diff --git a/package.json b/package.json
index 09c98f79..1f4c2f77 100644
--- a/package.json
+++ b/package.json
@@ -22,7 +22,6 @@
   "dependencies": {
     "bezier-easing": "^1.1.0",
     "clipboard": "^1.7.1",
-    "clunderscore": "^1.0.3",
     "compression": "^1.7.0",
     "diff-match-patch": "^1.0.0",
     "file-saver": "^1.3.3",
diff --git a/src/components/App.vue b/src/components/App.vue
index b15f1967..9d6434ef 100644
--- a/src/components/App.vue
+++ b/src/components/App.vue
@@ -22,6 +22,32 @@ Vue.directive('focus', {
   },
 });
 
+const setVisible = (el, value) => {
+  el.style.display = value ? '' : 'none';
+  if (value) {
+    el.removeAttribute('aria-hidden');
+  } else {
+    el.setAttribute('aria-hidden', 'true');
+  }
+};
+Vue.directive('show', {
+  bind(el, { value }) {
+    setVisible(el, value);
+  },
+  update(el, { value, oldValue }) {
+    if (value !== oldValue) {
+      setVisible(el, value);
+    }
+  },
+});
+
+Vue.directive('title', {
+  bind(el, { value }) {
+    el.title = value;
+    el.setAttribute('aria-label', value);
+  },
+});
+
 export default {
   components: {
     Layout,
diff --git a/src/components/ButtonBar.vue b/src/components/ButtonBar.vue
index 9690027a..24a62744 100644
--- a/src/components/ButtonBar.vue
+++ b/src/components/ButtonBar.vue
@@ -1,24 +1,24 @@
 <template>
   <div class="button-bar">
     <div class="button-bar__inner button-bar__inner--top">
-      <div class="button-bar__button" :class="{ 'button-bar__button--on': localSettings.showNavigationBar }" @click="toggleNavigationBar()">
+      <div class="button-bar__button" :class="{ 'button-bar__button--on': localSettings.showNavigationBar }" @click="toggleNavigationBar()" v-title="'Toggle navigation bar'">
         <icon-navigation-bar></icon-navigation-bar>
       </div>
-      <div class="button-bar__button" :class="{ 'button-bar__button--on': localSettings.showSidePreview }" @click="toggleSidePreview()">
+      <div class="button-bar__button" :class="{ 'button-bar__button--on': localSettings.showSidePreview }" @click="toggleSidePreview()" v-title="'Toggle side preview'">
         <icon-side-preview></icon-side-preview>
       </div>
-      <div class="button-bar__button" @click="toggleEditor(false)">
+      <div class="button-bar__button" @click="toggleEditor(false)" v-title="'Reader mode'">
         <icon-eye></icon-eye>
       </div>
     </div>
     <div class="button-bar__inner button-bar__inner--bottom">
-      <div class="button-bar__button" :class="{ 'button-bar__button--on': localSettings.focusMode }" @click="toggleFocusMode()">
+      <div class="button-bar__button" :class="{ 'button-bar__button--on': localSettings.focusMode }" @click="toggleFocusMode()" v-title="'Toggle focus mode'">
         <icon-target></icon-target>
       </div>
-      <div class="button-bar__button" :class="{ 'button-bar__button--on': localSettings.scrollSync }" @click="toggleScrollSync()">
+      <div class="button-bar__button" :class="{ 'button-bar__button--on': localSettings.scrollSync }" @click="toggleScrollSync()" v-title="'Toggle scroll sync'">
         <icon-scroll-sync></icon-scroll-sync>
       </div>
-      <div class="button-bar__button" :class="{ 'button-bar__button--on': localSettings.showStatusBar }" @click="toggleStatusBar()">
+      <div class="button-bar__button" :class="{ 'button-bar__button--on': localSettings.showStatusBar }" @click="toggleStatusBar()" v-title="'Toggle status bar'">
         <icon-status-bar></icon-status-bar>
       </div>
     </div>
diff --git a/src/components/Explorer.vue b/src/components/Explorer.vue
index 5f567aee..d8cde861 100644
--- a/src/components/Explorer.vue
+++ b/src/components/Explorer.vue
@@ -2,20 +2,20 @@
   <div class="explorer flex flex--column">
     <div class="side-title flex flex--row flex--space-between">
       <div class="flex flex--row">
-        <button class="side-title__button button" @click="newItem()">
+        <button class="side-title__button button" @click="newItem()" v-title="'New file'">
           <icon-file-plus></icon-file-plus>
         </button>
-        <button class="side-title__button button" @click="newItem(true)">
+        <button class="side-title__button button" @click="newItem(true)" v-title="'New folder'">
           <icon-folder-plus></icon-folder-plus>
         </button>
-        <button class="side-title__button button" @click="editItem()">
+        <button class="side-title__button button" @click="editItem()" v-title="'Rename'">
           <icon-pen></icon-pen>
         </button>
-        <button class="side-title__button button" @click="deleteItem()">
+        <button class="side-title__button button" @click="deleteItem()" v-title="'Remove'">
           <icon-delete></icon-delete>
         </button>
       </div>
-      <button class="side-title__button button" @click="toggleExplorer(false)">
+      <button class="side-title__button button" @click="toggleExplorer(false)" v-title="'Close explorer'">
         <icon-close></icon-close>
       </button>
     </div>
diff --git a/src/components/Layout.vue b/src/components/Layout.vue
index 4273ec2d..4da85037 100644
--- a/src/components/Layout.vue
+++ b/src/components/Layout.vue
@@ -1,7 +1,7 @@
 <template>
   <div class="layout">
     <div class="layout__panel flex flex--row" :class="{'flex--end': styles.showSideBar}">
-      <div class="layout__panel layout__panel--explorer" v-show="styles.showExplorer" :style="{ width: constants.explorerWidth + 'px' }">
+      <div class="layout__panel layout__panel--explorer" v-show="styles.showExplorer" :aria-hidden="!styles.showExplorer" :style="{ width: constants.explorerWidth + 'px' }">
         <explorer></explorer>
       </div>
       <div class="layout__panel flex flex--column" :style="{ width: styles.innerWidth + 'px' }">
diff --git a/src/components/Modal.vue b/src/components/Modal.vue
index c7d04528..1ed60e0d 100644
--- a/src/components/Modal.vue
+++ b/src/components/Modal.vue
@@ -1,5 +1,5 @@
 <template>
-  <div class="modal" @keyup.esc="onEscape">
+  <div class="modal" @keyup.esc="onEscape" @keydown.tab="onTab">
     <file-properties-modal v-if="config.type === 'fileProperties'"></file-properties-modal>
     <settings-modal v-else-if="config.type === 'settings'"></settings-modal>
     <templates-modal v-else-if="config.type === 'templates'"></templates-modal>
@@ -66,6 +66,10 @@ import BloggerPagePublishModal from './modals/BloggerPagePublishModal';
 import ZendeskAccountModal from './modals/ZendeskAccountModal';
 import ZendeskPublishModal from './modals/ZendeskPublishModal';
 
+const getTabbables = container => container.querySelectorAll('a[href], button, .textfield')
+  // Filter enabled and visible element
+  .cl_filter(el => !el.disabled && el.offsetParent !== null);
+
 export default {
   components: {
     FilePropertiesModal,
@@ -102,6 +106,18 @@ export default {
       this.config.reject();
       editorEngineSvc.clEditor.focus();
     },
+    onTab(evt) {
+      const tabbables = getTabbables(this.$el);
+      const firstTabbable = tabbables[0];
+      const lastTabbable = tabbables[tabbables.length - 1];
+      if (evt.shiftKey && firstTabbable === evt.target) {
+        evt.preventDefault();
+        lastTabbable.focus();
+      } else if (!evt.shiftKey && lastTabbable === evt.target) {
+        evt.preventDefault();
+        firstTabbable.focus();
+      }
+    },
     onFocusInOut(evt) {
       const isFocusIn = evt.type === 'focusin';
       if (evt.target.parentNode && evt.target.parentNode.parentNode) {
@@ -127,12 +143,8 @@ export default {
   mounted() {
     window.addEventListener('focusin', this.onFocusInOut);
     window.addEventListener('focusout', this.onFocusInOut);
-    const eltToFocus = this.$el.querySelector('input.text-input')
-      || this.$el.querySelector('.textfield')
-      || this.$el.querySelector('.button');
-    if (eltToFocus) {
-      eltToFocus.focus();
-    }
+    const tabbables = getTabbables(this.$el);
+    tabbables[0].focus();
   },
   destroyed() {
     window.removeEventListener('focusin', this.onFocusInOut);
@@ -237,6 +249,10 @@ export default {
   .form-entry--focused & {
     color: darken($link-color, 10%);
   }
+
+  .form-entry--error & {
+    color: darken($error-color, 10%);
+  }
 }
 
 .form-entry__field {
@@ -248,6 +264,10 @@ export default {
   .form-entry--focused & {
     border-color: $link-color;
   }
+
+  .form-entry--error & {
+    border-color: $error-color;
+  }
 }
 
 .form-entry__actions {
@@ -286,4 +306,51 @@ export default {
   line-height: 1.4;
   margin: 0.25em 0;
 }
+
+.tabs {
+  border-bottom: 1px solid $hr-color;
+  margin-bottom: 2em;
+
+  &::after {
+    content: '';
+    display: block;
+    clear: both;
+  }
+}
+
+.tabs__tab {
+  width: 50%;
+  float: left;
+  text-align: center;
+  line-height: 1.4;
+  font-weight: 400;
+  font-size: 1.1em;
+}
+
+.tabs__tab > a {
+  width: 100%;
+  text-decoration: none;
+  padding: 0.67em 0.33em;
+  cursor: pointer;
+  border-bottom: 2px solid transparent;
+  border-top-left-radius: $border-radius-base;
+  border-top-right-radius: $border-radius-base;
+  color: $link-color;
+
+  &:hover,
+  &:focus {
+    background-color: rgba(0, 0, 0, 0.067);
+  }
+}
+
+.tabs__tab--active > a {
+  border-bottom: 2px solid $link-color;
+  color: inherit;
+  cursor: auto;
+
+  &:hover,
+  &:focus {
+    background-color: transparent;
+  }
+}
 </style>
diff --git a/src/components/NavigationBar.vue b/src/components/NavigationBar.vue
index 55a93435..65a0e7db 100644
--- a/src/components/NavigationBar.vue
+++ b/src/components/NavigationBar.vue
@@ -1,12 +1,12 @@
 <template>
   <div class="navigation-bar" :class="{'navigation-bar--editor': styles.showEditor}">
     <div class="navigation-bar__inner navigation-bar__inner--left navigation-bar__inner--button">
-      <button class="navigation-bar__button button" @click="toggleExplorer()">
+      <button class="navigation-bar__button button" @click="toggleExplorer()" v-title="'Toggle explorer'">
         <icon-folder></icon-folder>
       </button>
     </div>
     <div class="navigation-bar__inner navigation-bar__inner--right navigation-bar__inner--button">
-      <button class="navigation-bar__button navigation-bar__button--stackedit button" @click="toggleSideBar()">
+      <button class="navigation-bar__button navigation-bar__button--stackedit button" @click="toggleSideBar()" v-title="'Toggle side bar'">
         <icon-provider provider-id="stackedit"></icon-provider>
       </button>
     </div>
@@ -19,55 +19,55 @@
       <div class="navigation-bar__title navigation-bar__title--text text-input" :style="{width: titleWidth + 'px'}">{{title}}</div>
       <input class="navigation-bar__title navigation-bar__title--input text-input" :class="{'navigation-bar__title--focus': titleFocus, 'navigation-bar__title--scrolling': titleScrolling}" :style="{width: titleWidth + 'px'}" @focus="editTitle(true)" @blur="editTitle(false)" @keyup.enter="submitTitle()" @keyup.esc="submitTitle(true)" @mouseenter="titleHover = true" @mouseleave="titleHover = false" v-model="title">
       <div class="flex flex--row" :class="{'navigation-bar__hidden': styles.hideLocations}">
-        <a class="navigation-bar__button navigation-bar__button--location button" :class="{'navigation-bar__button--blink': location.id === currentLocation.id}" v-for="location in syncLocations" :key="location.id" :href="location.url" target="_blank">
+        <a class="navigation-bar__button navigation-bar__button--location button" :class="{'navigation-bar__button--blink': location.id === currentLocation.id}" v-for="location in syncLocations" :key="location.id" :href="location.url" target="_blank" v-title="'Synchronized location'">
           <icon-provider :provider-id="location.providerId"></icon-provider>
         </a>
-        <button class="navigation-bar__button navigation-bar__button--sync button" :disabled="!isSyncPossible || isSyncRequested || offline" @click="requestSync">
+        <button class="navigation-bar__button navigation-bar__button--sync button" :disabled="!isSyncPossible || isSyncRequested || offline" @click="requestSync" v-title="'Synchronize now'">
           <icon-sync></icon-sync>
         </button>
-        <a class="navigation-bar__button navigation-bar__button--location button" :class="{'navigation-bar__button--blink': location.id === currentLocation.id}" v-for="location in publishLocations" :key="location.id" :href="location.url" target="_blank">
+        <a class="navigation-bar__button navigation-bar__button--location button" :class="{'navigation-bar__button--blink': location.id === currentLocation.id}" v-for="location in publishLocations" :key="location.id" :href="location.url" target="_blank" v-title="'Publish location'">
           <icon-provider :provider-id="location.providerId"></icon-provider>
         </a>
-        <button class="navigation-bar__button navigation-bar__button--publish button" :disabled="!publishLocations.length || isPublishRequested || offline" @click="requestPublish">
+        <button class="navigation-bar__button navigation-bar__button--publish button" :disabled="!publishLocations.length || isPublishRequested || offline" @click="requestPublish"v-title="'Publish now'">
           <icon-upload></icon-upload>
         </button>
       </div>
     </div>
     <div class="navigation-bar__inner navigation-bar__inner--edit-buttons">
-      <button class="navigation-bar__button button" @click="pagedownClick('bold')">
+      <button class="navigation-bar__button button" @click="pagedownClick('bold')" v-title="'Bold'">
         <icon-format-bold></icon-format-bold>
       </button>
-      <button class="navigation-bar__button button" @click="pagedownClick('italic')">
+      <button class="navigation-bar__button button" @click="pagedownClick('italic')" v-title="'Italic'">
         <icon-format-italic></icon-format-italic>
       </button>
-      <button class="navigation-bar__button button" @click="pagedownClick('strikethrough')">
+      <button class="navigation-bar__button button" @click="pagedownClick('strikethrough')" v-title="'Strikethrough'">
         <icon-format-strikethrough></icon-format-strikethrough>
       </button>
-      <button class="navigation-bar__button button" @click="pagedownClick('heading')">
+      <button class="navigation-bar__button button" @click="pagedownClick('heading')" v-title="'Heading'">
         <icon-format-size></icon-format-size>
       </button>
-      <button class="navigation-bar__button button" @click="pagedownClick('ulist')">
+      <button class="navigation-bar__button button" @click="pagedownClick('ulist')" v-title="'Unordered list'">
         <icon-format-list-bulleted></icon-format-list-bulleted>
       </button>
-      <button class="navigation-bar__button button" @click="pagedownClick('olist')">
+      <button class="navigation-bar__button button" @click="pagedownClick('olist')" v-title="'Ordered list'">
         <icon-format-list-numbers></icon-format-list-numbers>
       </button>
-      <button class="navigation-bar__button button" @click="pagedownClick('table')">
+      <button class="navigation-bar__button button" @click="pagedownClick('table')" v-title="'Table'">
         <icon-table></icon-table>
       </button>
-      <button class="navigation-bar__button button" @click="pagedownClick('quote')">
+      <button class="navigation-bar__button button" @click="pagedownClick('quote')" v-title="'Blockquote'">
         <icon-format-quote-close></icon-format-quote-close>
       </button>
-      <button class="navigation-bar__button button" @click="pagedownClick('code')">
+      <button class="navigation-bar__button button" @click="pagedownClick('code')" v-title="'Code'">
         <icon-code-tags></icon-code-tags>
       </button>
-      <button class="navigation-bar__button button" @click="pagedownClick('link')">
+      <button class="navigation-bar__button button" @click="pagedownClick('link')" v-title="'Link'">
         <icon-link-variant></icon-link-variant>
       </button>
-      <button class="navigation-bar__button button" @click="pagedownClick('image')">
+      <button class="navigation-bar__button button" @click="pagedownClick('image')" v-title="'Image'">
         <icon-file-image></icon-file-image>
       </button>
-      <button class="navigation-bar__button button" @click="pagedownClick('hr')">
+      <button class="navigation-bar__button button" @click="pagedownClick('hr')" v-title="'Horizontal rule'">
         <icon-format-horizontal-rule></icon-format-horizontal-rule>
       </button>
     </div>
@@ -368,14 +368,14 @@ export default {
   }
 }
 
-$r: 9px;
+$r: 10px;
 $d: $r * 2;
 $b: $d/10;
 $t: 3000ms;
 
 .navigation-bar__spinner {
   width: 22px;
-  margin: 8px 0 0 8px;
+  margin: 7px 0 0 8px;
   color: #b2b2b2;
 
   .icon {
diff --git a/src/components/SideBar.vue b/src/components/SideBar.vue
index 5d2ee696..d31f4f98 100644
--- a/src/components/SideBar.vue
+++ b/src/components/SideBar.vue
@@ -1,13 +1,13 @@
 <template>
   <div class="side-bar flex flex--column">
     <div class="side-title flex flex--row">
-      <button v-if="panel !== 'menu'" class="side-title__button button" @click="setPanel('menu')">
+      <button v-if="panel !== 'menu'" class="side-title__button button" @click="setPanel('menu')" v-title="'Main menu'">
         <icon-arrow-left></icon-arrow-left>
       </button>
       <div class="side-title__title">
         {{panelName}}
       </div>
-      <button class="side-title__button button" @click="toggleSideBar(false)">
+      <button class="side-title__button button" @click="toggleSideBar(false)" v-title="'Close side bar'">
         <icon-close></icon-close>
       </button>
     </div>
diff --git a/src/components/StatusBar.vue b/src/components/StatusBar.vue
index 99d321e1..3e10ad2f 100644
--- a/src/components/StatusBar.vue
+++ b/src/components/StatusBar.vue
@@ -3,7 +3,7 @@
     <div class="stat-panel__block stat-panel__block--left" v-if="styles.showEditor">
       <span class="stat-panel__block-name">
         Markdown
-        <small v-show="textSelection">(selection)</small>
+        <small v-if="textSelection">(selection)</small>
       </span>
       <span v-for="stat in textStats" :key="stat.id">
         <span class="stat-panel__value">{{stat.value}}</span> {{stat.name}}
@@ -13,7 +13,7 @@
     <div class="stat-panel__block stat-panel__block--right">
       <span class="stat-panel__block-name">
         HTML
-        <small v-show="htmlSelection">(selection)</small>
+        <small v-if="htmlSelection">(selection)</small>
       </span>
       <span v-for="stat in htmlStats" :key="stat.id">
         <span class="stat-panel__value">{{stat.value}}</span> {{stat.name}}
diff --git a/src/components/common/app.scss b/src/components/common/app.scss
index 6b49215e..d4067513 100644
--- a/src/components/common/app.scss
+++ b/src/components/common/app.scss
@@ -189,48 +189,6 @@ textarea {
   width: 100%;
 }
 
-.tabs {
-  border-bottom: 1px solid $hr-color;
-  margin-bottom: 2em;
-
-  &::after {
-    content: '';
-    display: block;
-    clear: both;
-  }
-}
-
-.tabs__tab {
-  width: 50%;
-  float: left;
-  text-align: center;
-  line-height: 1.4;
-  padding: 0.67em 0.33em;
-  cursor: pointer;
-  border-bottom: 2px solid transparent;
-  border-top-left-radius: $border-radius-base;
-  border-top-right-radius: $border-radius-base;
-  color: $link-color;
-  font-weight: 400;
-  font-size: 1.1em;
-
-  &:hover,
-  &:focus {
-    background-color: rgba(0, 0, 0, 0.067);
-  }
-}
-
-.tabs__tab--active {
-  border-bottom: 2px solid $link-color;
-  color: inherit;
-  cursor: auto;
-
-  &:hover,
-  &:focus {
-    background-color: transparent;
-  }
-}
-
 .logo-background {
   background: no-repeat center url('../assets/logo.svg');
   background-size: contain;
diff --git a/src/components/modals/AboutModal.vue b/src/components/modals/AboutModal.vue
index 0ba4ceed..2dabac28 100644
--- a/src/components/modals/AboutModal.vue
+++ b/src/components/modals/AboutModal.vue
@@ -1,5 +1,5 @@
 <template>
-  <div class="modal__inner-1 modal__inner-1--about-modal">
+  <div class="modal__inner-1 modal__inner-1--about-modal" role="dialog" aria-label="About">
     <div class="modal__inner-2">
       <div class="logo-background"></div>
       <div class="app-version">v{{version}} — © 2017 Benoit Schweblin</div>
diff --git a/src/components/modals/BloggerPagePublishModal.vue b/src/components/modals/BloggerPagePublishModal.vue
index fa3fb177..71173e38 100644
--- a/src/components/modals/BloggerPagePublishModal.vue
+++ b/src/components/modals/BloggerPagePublishModal.vue
@@ -1,11 +1,11 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Publish to Blogger Page">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="bloggerPage"></icon-provider>
       </div>
       <p>This will publish <b>{{currentFileName}}</b> to your <b>Blogger Page</b>.</p>
-      <form-entry label="Blog URL">
+      <form-entry label="Blog URL" error="blogUrl">
         <input slot="field" class="textfield" type="text" v-model.trim="blogUrl" @keyup.enter="resolve()">
         <div class="form-entry__info">
           <b>Example:</b> http://example.blogger.com/
@@ -49,7 +49,9 @@ export default modalTemplate({
   },
   methods: {
     resolve() {
-      if (this.blogUrl) {
+      if (!this.blogUrl) {
+        this.setError('blogUrl');
+      } else {
         // Return new location
         const location = bloggerPageProvider.makeLocation(
           this.config.token, this.blogUrl, this.pageId);
diff --git a/src/components/modals/BloggerPublishModal.vue b/src/components/modals/BloggerPublishModal.vue
index a1ecde82..cc3d0ee3 100644
--- a/src/components/modals/BloggerPublishModal.vue
+++ b/src/components/modals/BloggerPublishModal.vue
@@ -1,11 +1,11 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Publish to Blogger">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="blogger"></icon-provider>
       </div>
       <p>This will publish <b>{{currentFileName}}</b> to your <b>Blogger</b> site.</p>
-      <form-entry label="Blog URL">
+      <form-entry label="Blog URL" error="blogUrl">
         <input slot="field" class="textfield" type="text" v-model.trim="blogUrl" @keyup.enter="resolve()">
         <div class="form-entry__info">
           <b>Example:</b> http://example.blogger.com/
@@ -50,7 +50,9 @@ export default modalTemplate({
   },
   methods: {
     resolve() {
-      if (this.blogUrl) {
+      if (!this.blogUrl) {
+        this.setError('blogUrl');
+      } else {
         // Return new location
         const location = bloggerProvider.makeLocation(
           this.config.token, this.blogUrl, this.postId);
diff --git a/src/components/modals/DropboxAccountModal.vue b/src/components/modals/DropboxAccountModal.vue
index 2b5cc560..d28eb98e 100644
--- a/src/components/modals/DropboxAccountModal.vue
+++ b/src/components/modals/DropboxAccountModal.vue
@@ -1,5 +1,5 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Link Dropbox account">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="dropbox"></icon-provider>
diff --git a/src/components/modals/DropboxPublishModal.vue b/src/components/modals/DropboxPublishModal.vue
index 00401a5f..3aff3650 100644
--- a/src/components/modals/DropboxPublishModal.vue
+++ b/src/components/modals/DropboxPublishModal.vue
@@ -1,11 +1,11 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Publish to Dropbox">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="dropbox"></icon-provider>
       </div>
       <p>This will publish <b>{{currentFileName}}</b> to your <b>Dropbox</b>.</p>
-      <form-entry label="File path">
+      <form-entry label="File path" error="path">
         <input slot="field" class="textfield" type="text" v-model.trim="path" @keyup.enter="resolve()">
         <div class="form-entry__info">
           <b>Example:</b> {{config.token.fullAccess ? '' : '/Applications/StackEdit (restricted)'}}/path/to/My Document.html<br>
@@ -46,7 +46,9 @@ export default modalTemplate({
   },
   methods: {
     resolve() {
-      if (dropboxProvider.checkPath(this.path)) {
+      if (!dropboxProvider.checkPath(this.path)) {
+        this.setError('path');
+      } else {
         // Return new location
         const location = dropboxProvider.makeLocation(this.config.token, this.path);
         location.templateId = this.selectedTemplate;
diff --git a/src/components/modals/DropboxSyncModal.vue b/src/components/modals/DropboxSyncModal.vue
index 27d6085c..caadb5c8 100644
--- a/src/components/modals/DropboxSyncModal.vue
+++ b/src/components/modals/DropboxSyncModal.vue
@@ -1,11 +1,11 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Synchronize with Dropbox">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="dropbox"></icon-provider>
       </div>
       <p>This will save <b>{{currentFileName}}</b> to your <b>Dropbox</b> and keep it synchronized.</p>
-      <form-entry label="File path">
+      <form-entry label="File path" error="path">
         <input slot="field" class="textfield" type="text" v-model.trim="path" @keyup.enter="resolve()">
         <div class="form-entry__info">
           <b>Example:</b> {{config.token.fullAccess ? '' : '/Applications/StackEdit (restricted)'}}/path/to/My Document.md<br>
@@ -33,7 +33,9 @@ export default modalTemplate({
   },
   methods: {
     resolve() {
-      if (dropboxProvider.checkPath(this.path)) {
+      if (!dropboxProvider.checkPath(this.path)) {
+        this.setError('path');
+      } else {
         // Return new location
         const location = dropboxProvider.makeLocation(this.config.token, this.path);
         this.config.resolve(location);
diff --git a/src/components/modals/FilePropertiesModal.vue b/src/components/modals/FilePropertiesModal.vue
index c79ff0e6..d2f210d4 100644
--- a/src/components/modals/FilePropertiesModal.vue
+++ b/src/components/modals/FilePropertiesModal.vue
@@ -1,19 +1,24 @@
 <template>
-  <div class="modal__inner-1 modal__inner-1--file-properties">
+  <div class="modal__inner-1 modal__inner-1--file-properties" role="dialog" aria-label="File properties">
     <div class="modal__inner-2">
       <div class="tabs flex flex--row">
-        <div class="tabs__tab flex flex--column flex--center" :class="{'tabs__tab--active': tab === 'custom'}" @click="tab = 'custom'">
+        <tab :active="tab === 'custom'" @click="tab = 'custom'">
           Current file properties
-        </div>
-        <div class="tabs__tab flex flex--column flex--center" :class="{'tabs__tab--active': tab === 'default'}" @click="tab = 'default'">
+        </tab>
+        <tab :active="tab === 'default'" @click="tab = 'default'">
           Default properties
-        </div>
+        </tab>
       </div>
-      <div class="form-entry">
+      <div class="form-entry" v-if="tab === 'custom'" role="tabpanel" aria-label="Current file properties">
         <label class="form-entry__label">YAML</label>
         <div class="form-entry__field">
-          <code-editor v-if="tab === 'custom'" lang="yaml" :value="customProperties" key="custom-properties" @changed="setCustomProperties"></code-editor>
-          <code-editor v-else lang="yaml" :value="defaultProperties" disabled="true" key="default-properties"></code-editor>
+          <code-editor lang="yaml" :value="customProperties" key="custom-properties" @changed="setCustomProperties"></code-editor>
+        </div>
+      </div>
+      <div class="form-entry" v-else-if="tab === 'default'" role="tabpanel" aria-label="Default properties">
+        <label class="form-entry__label">YAML</label>
+        <div class="form-entry__field">
+          <code-editor lang="yaml" :value="defaultProperties" key="default-properties" disabled="true"></code-editor>
         </div>
       </div>
       <div class="modal__error modal__error--file-properties">{{error}}</div>
@@ -28,6 +33,7 @@
 <script>
 import yaml from 'js-yaml';
 import { mapGetters } from 'vuex';
+import Tab from './Tab';
 import CodeEditor from '../CodeEditor';
 import defaultProperties from '../../data/defaultFileProperties.yml';
 
@@ -35,6 +41,7 @@ const emptyProperties = '# Add custom properties for the current file here to ov
 
 export default {
   components: {
+    Tab,
     CodeEditor,
   },
   data: () => ({
diff --git a/src/components/modals/FormEntry.vue b/src/components/modals/FormEntry.vue
index 9d18a722..5c129d02 100644
--- a/src/components/modals/FormEntry.vue
+++ b/src/components/modals/FormEntry.vue
@@ -1,5 +1,5 @@
 <template>
-  <div class="form-entry">
+  <div class="form-entry" :error="error">
     <label class="form-entry__label" :for="uid">{{label}}</label>
     <div class="form-entry__field">
       <slot name="field"></slot>
@@ -12,7 +12,7 @@
 import utils from '../../services/utils';
 
 export default {
-  props: ['label'],
+  props: ['label', 'error'],
   data: () => ({
     uid: utils.uid(),
   }),
diff --git a/src/components/modals/GistPublishModal.vue b/src/components/modals/GistPublishModal.vue
index f9fc2a5c..ce14d303 100644
--- a/src/components/modals/GistPublishModal.vue
+++ b/src/components/modals/GistPublishModal.vue
@@ -1,11 +1,11 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Publish to Gist">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="gist"></icon-provider>
       </div>
       <p>This will publish <b>{{currentFileName}}</b> to a <b>Gist</b>.</p>
-      <form-entry label="Filename">
+      <form-entry label="Filename" error="filename">
         <input slot="field" class="textfield" type="text" v-model.trim="filename" @keyup.enter="resolve()">
       </form-entry>
       <div class="form-entry">
@@ -60,7 +60,9 @@ export default modalTemplate({
   },
   methods: {
     resolve() {
-      if (this.filename) {
+      if (!this.filename) {
+        this.setError('filename');
+      } else {
         // Return new location
         const location = gistProvider.makeLocation(
           this.config.token, this.filename, this.isPublic, this.gistId);
diff --git a/src/components/modals/GistSyncModal.vue b/src/components/modals/GistSyncModal.vue
index 4ba24702..936b11c1 100644
--- a/src/components/modals/GistSyncModal.vue
+++ b/src/components/modals/GistSyncModal.vue
@@ -1,11 +1,11 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Synchronize with Gist">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="gist"></icon-provider>
       </div>
       <p>This will save <b>{{currentFileName}}</b> to a <b>Gist</b> and keep it synchronized.</p>
-      <form-entry label="Filename">
+      <form-entry label="Filename" error="filename">
         <input slot="field" class="textfield" type="text" v-model.trim="filename" @keyup.enter="resolve()">
       </form-entry>
       <div class="form-entry">
@@ -46,7 +46,9 @@ export default modalTemplate({
   },
   methods: {
     resolve() {
-      if (this.filename) {
+      if (!this.filename) {
+        this.setError('filename');
+      } else {
         // Return new location
         const location = gistProvider.makeLocation(
           this.config.token, this.filename, this.isPublic, this.gistId);
diff --git a/src/components/modals/GithubAccountModal.vue b/src/components/modals/GithubAccountModal.vue
index b81087fa..8f923d84 100644
--- a/src/components/modals/GithubAccountModal.vue
+++ b/src/components/modals/GithubAccountModal.vue
@@ -1,10 +1,10 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Link GitHub account">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="github"></icon-provider>
       </div>
-      <p>This will link your <b>Github</b> account to your <b>StackEdit</b> workspace.</p>
+      <p>This will link your <b>GitHub</b> account to your <b>StackEdit</b> workspace.</p>
       <div class="form-entry">
         <div class="form-entry__checkbox">
           <label>
diff --git a/src/components/modals/GithubPublishModal.vue b/src/components/modals/GithubPublishModal.vue
index 865bfc53..84fcd2ee 100644
--- a/src/components/modals/GithubPublishModal.vue
+++ b/src/components/modals/GithubPublishModal.vue
@@ -1,11 +1,11 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Publish to GitHub">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="github"></icon-provider>
       </div>
       <p>This will publish <b>{{currentFileName}}</b> to your <b>GitHub</b> repository.</p>
-      <form-entry label="Repository URL">
+      <form-entry label="Repository URL" error="repoUrl">
         <input slot="field" class="textfield" type="text" v-model.trim="repoUrl" @keyup.enter="resolve()">
         <div class="form-entry__info">
           <b>Example:</b> https://github.com/benweet/stackedit
@@ -17,7 +17,7 @@
           If not provided, the master branch will be used.
         </div>
       </form-entry>
-      <form-entry label="File path">
+      <form-entry label="File path" error="path">
         <input slot="field" class="textfield" type="text" v-model.trim="path" @keyup.enter="resolve()">
         <div class="form-entry__info">
           <b>Example:</b> docs/README.md<br>
@@ -60,9 +60,17 @@ export default modalTemplate({
   },
   methods: {
     resolve() {
+      if (!this.repoUrl) {
+        this.setError('repoUrl');
+      }
+      if (!this.path) {
+        this.setError('path');
+      }
       if (this.repoUrl && this.path) {
-        const parsedRepo = this.repoUrl.match(/[/:]?([^/:]+)\/([^/]+?)(?:\.git)?$/);
-        if (parsedRepo) {
+        const parsedRepo = this.repoUrl.match(/[/:]?([^/:]+)\/([^/]+?)(?:\.git|\/)?$/);
+        if (!parsedRepo) {
+          this.setError('repoUrl');
+        } else {
           // Return new location
           const location = githubProvider.makeLocation(
             this.config.token, parsedRepo[1], parsedRepo[2], this.branch || 'master', this.path);
diff --git a/src/components/modals/GithubSyncModal.vue b/src/components/modals/GithubSyncModal.vue
index 7e691bd5..3553b612 100644
--- a/src/components/modals/GithubSyncModal.vue
+++ b/src/components/modals/GithubSyncModal.vue
@@ -1,11 +1,11 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Synchronize with GitHub">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="github"></icon-provider>
       </div>
       <p>This will save <b>{{currentFileName}}</b> to your <b>GitHub</b> repository and keep it synchronized.</p>
-      <form-entry label="Repository URL">
+      <form-entry label="Repository URL" error="repoUrl">
         <input slot="field" class="textfield" type="text" v-model.trim="repoUrl" @keyup.enter="resolve()">
         <div class="form-entry__info">
           <b>Example:</b> https://github.com/benweet/stackedit
@@ -17,7 +17,7 @@
           If not provided, the master branch will be used.
         </div>
       </form-entry>
-      <form-entry label="File path">
+      <form-entry label="File path" error="path">
         <input slot="field" class="textfield" type="text" v-model.trim="path" @keyup.enter="resolve()">
         <div class="form-entry__info">
           <b>Example:</b> docs/README.md<br>
@@ -49,9 +49,17 @@ export default modalTemplate({
   },
   methods: {
     resolve() {
+      if (!this.repoUrl) {
+        this.setError('repoUrl');
+      }
+      if (!this.path) {
+        this.setError('path');
+      }
       if (this.repoUrl && this.path) {
-        const parsedRepo = this.repoUrl.match(/[/:]?([^/:]+)\/([^/]+?)(?:\.git)?$/);
-        if (parsedRepo) {
+        const parsedRepo = this.repoUrl.match(/[/:]?([^/:]+)\/([^/]+?)(?:\.git|\/)?$/);
+        if (!parsedRepo) {
+          this.setError('repoUrl');
+        } else {
           // Return new location
           const location = githubProvider.makeLocation(
             this.config.token, parsedRepo[1], parsedRepo[2], this.branch || 'master', this.path);
diff --git a/src/components/modals/GoogleDrivePublishModal.vue b/src/components/modals/GoogleDrivePublishModal.vue
index 1f7c995f..50b77555 100644
--- a/src/components/modals/GoogleDrivePublishModal.vue
+++ b/src/components/modals/GoogleDrivePublishModal.vue
@@ -1,5 +1,5 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Publish to Google Drive">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="googleDrive"></icon-provider>
diff --git a/src/components/modals/GoogleDriveSyncModal.vue b/src/components/modals/GoogleDriveSyncModal.vue
index 3ae07ddd..61411c6d 100644
--- a/src/components/modals/GoogleDriveSyncModal.vue
+++ b/src/components/modals/GoogleDriveSyncModal.vue
@@ -1,5 +1,5 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Synchronize with Google Drive">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="googleDrive"></icon-provider>
diff --git a/src/components/modals/GooglePhotoModal.vue b/src/components/modals/GooglePhotoModal.vue
index 03d24984..5ecf4cfc 100644
--- a/src/components/modals/GooglePhotoModal.vue
+++ b/src/components/modals/GooglePhotoModal.vue
@@ -1,5 +1,5 @@
 <template>
-  <div class="modal__inner-1 modal__inner-1--google-photo">
+  <div class="modal__inner-1 modal__inner-1--google-photo" role="dialog" aria-label="Import Google Photo">
     <div class="modal__inner-2">
       <div class="google-photo__tumbnail" :style="{'background-image': thumbnailUrl}"></div>
       <form-entry label="Title (optional)">
diff --git a/src/components/modals/HtmlExportModal.vue b/src/components/modals/HtmlExportModal.vue
index 09f6a76b..273ef948 100644
--- a/src/components/modals/HtmlExportModal.vue
+++ b/src/components/modals/HtmlExportModal.vue
@@ -1,5 +1,5 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Export to HTML">
     <div class="modal__inner-2">
       <form-entry label="Template">
         <select slot="field" class="textfield" v-model="selectedTemplate" @keyup.enter="resolve()">
diff --git a/src/components/modals/ImageModal.vue b/src/components/modals/ImageModal.vue
index be0b7ad5..97d14a61 100644
--- a/src/components/modals/ImageModal.vue
+++ b/src/components/modals/ImageModal.vue
@@ -1,8 +1,8 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Insert image">
     <div class="modal__inner-2">
       <p>Please provide a <b>URL</b> for your image.
-      <form-entry label="URL">
+      <form-entry label="URL" error="url">
         <input slot="field" class="textfield" type="text" v-model.trim="url" @keyup.enter="resolve()">
       </form-entry>
       <menu-entry @click.native="openGooglePhotos(token)" v-for="token in googlePhotosTokens" :key="token.sub">
@@ -23,23 +23,18 @@
 </template>
 
 <script>
-import { mapGetters } from 'vuex';
+import modalTemplate from './modalTemplate';
 import MenuEntry from '../menus/MenuEntry';
-import FormEntry from './FormEntry';
 import googleHelper from '../../services/providers/helpers/googleHelper';
 
-export default {
+export default modalTemplate({
   components: {
-    FormEntry,
     MenuEntry,
   },
   data: () => ({
     url: '',
   }),
   computed: {
-    ...mapGetters('modal', [
-      'config',
-    ]),
     googlePhotosTokens() {
       const googleToken = this.$store.getters['data/googleTokens'];
       return Object.keys(googleToken)
@@ -50,7 +45,9 @@ export default {
   },
   methods: {
     resolve() {
-      if (this.url) {
+      if (!this.url) {
+        this.setError('url');
+      } else {
         const callback = this.config.callback;
         this.config.resolve();
         callback(this.url);
@@ -75,5 +72,5 @@ export default {
         }));
     },
   },
-};
+});
 </script>
diff --git a/src/components/modals/LinkModal.vue b/src/components/modals/LinkModal.vue
index cd8a66f4..53262bf6 100644
--- a/src/components/modals/LinkModal.vue
+++ b/src/components/modals/LinkModal.vue
@@ -1,8 +1,8 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Insert link">
     <div class="modal__inner-2">
       <p>Please provide a <b>URL</b> for your link.
-      <form-entry label="URL">
+      <form-entry label="URL" error="url">
         <input slot="field" class="textfield" type="text" v-model.trim="url" @keyup.enter="resolve()">
       </form-entry>
       <div class="modal__button-bar">
@@ -14,22 +14,17 @@
 </template>
 
 <script>
-import { mapGetters } from 'vuex';
-import FormEntry from './FormEntry';
+import modalTemplate from './modalTemplate';
 
-export default {
-  components: {
-    FormEntry,
-  },
+export default modalTemplate({
   data: () => ({
     url: '',
   }),
-  computed: mapGetters('modal', [
-    'config',
-  ]),
   methods: {
     resolve() {
-      if (this.url) {
+      if (!this.url) {
+        this.setError('url');
+      } else {
         const callback = this.config.callback;
         this.config.resolve();
         callback(this.url);
@@ -41,5 +36,5 @@ export default {
       callback(null);
     },
   },
-};
+});
 </script>
diff --git a/src/components/modals/PublishManagementModal.vue b/src/components/modals/PublishManagementModal.vue
index 64c6aee5..877ebf3b 100644
--- a/src/components/modals/PublishManagementModal.vue
+++ b/src/components/modals/PublishManagementModal.vue
@@ -1,5 +1,5 @@
 <template>
-  <div class="modal__inner-1 modal__inner-1--publish-management">
+  <div class="modal__inner-1 modal__inner-1--publish-management" role="dialog" aria-label="Manage publication locations">
     <div class="modal__inner-2">
       <p v-if="publishLocations.length"><b>{{currentFileName}}</b> is published to the following location(s):</p>
       <p v-else><b>{{currentFileName}}</b> is not published yet.</p>
diff --git a/src/components/modals/SettingsModal.vue b/src/components/modals/SettingsModal.vue
index 3ed1fe94..612fab76 100644
--- a/src/components/modals/SettingsModal.vue
+++ b/src/components/modals/SettingsModal.vue
@@ -1,19 +1,24 @@
 <template>
-  <div class="modal__inner-1 modal__inner-1--settings">
+  <div class="modal__inner-1 modal__inner-1--settings" role="dialog" aria-label="Settings">
     <div class="modal__inner-2">
       <div class="tabs flex flex--row">
-        <div class="tabs__tab flex flex--column flex--center" :class="{'tabs__tab--active': tab === 'custom'}" @click="tab = 'custom'">
+        <tab :active="tab === 'custom'" @click="tab = 'custom'">
           Custom settings
-        </div>
-        <div class="tabs__tab flex flex--column flex--center" :class="{'tabs__tab--active': tab === 'default'}" @click="tab = 'default'">
+        </tab>
+        <tab :active="tab === 'default'" @click="tab = 'default'">
           Default settings
-        </div>
+        </tab>
       </div>
-      <div class="form-entry">
+      <div class="form-entry" v-if="tab === 'custom'" role="tabpanel" aria-label="Custom settings">
         <label class="form-entry__label">YAML</label>
         <div class="form-entry__field form-entry__field--code-editor">
-          <code-editor v-if="tab === 'custom'" lang="yaml" :value="customSettings" key="custom-settings" @changed="setCustomSettings"></code-editor>
-          <code-editor v-else lang="yaml" :value="defaultSettings" disabled="true" key="default-settings"></code-editor>
+          <code-editor lang="yaml" :value="customSettings" key="custom-settings" @changed="setCustomSettings"></code-editor>
+        </div>
+      </div>
+      <div class="form-entry" v-else-if="tab === 'default'" role="tabpanel" aria-label="Default settings">
+        <label class="form-entry__label">YAML</label>
+        <div class="form-entry__field form-entry__field--code-editor">
+          <code-editor lang="yaml" :value="defaultSettings" key="default-settings" disabled="true"></code-editor>
         </div>
       </div>
       <div class="modal__error modal__error--settings">{{error}}</div>
@@ -28,6 +33,7 @@
 <script>
 import yaml from 'js-yaml';
 import { mapGetters } from 'vuex';
+import Tab from './Tab';
 import CodeEditor from '../CodeEditor';
 import defaultSettings from '../../data/defaultSettings.yml';
 
@@ -35,6 +41,7 @@ const emptySettings = '# Add your custom settings here to override the default s
 
 export default {
   components: {
+    Tab,
     CodeEditor,
   },
   data: () => ({
diff --git a/src/components/modals/SyncManagementModal.vue b/src/components/modals/SyncManagementModal.vue
index 7f82c9fa..12b14e97 100644
--- a/src/components/modals/SyncManagementModal.vue
+++ b/src/components/modals/SyncManagementModal.vue
@@ -1,5 +1,5 @@
 <template>
-  <div class="modal__inner-1 modal__inner-1--sync-management">
+  <div class="modal__inner-1 modal__inner-1--sync-management" role="dialog" aria-label="Manage synchronized locations">
     <div class="modal__inner-2">
       <p v-if="syncLocations.length"><b>{{currentFileName}}</b> is synchronized with the following location(s):</p>
       <p v-else><b>{{currentFileName}}</b> is not synchronized yet.</p>
diff --git a/src/components/modals/Tab.vue b/src/components/modals/Tab.vue
new file mode 100644
index 00000000..6d5d55e5
--- /dev/null
+++ b/src/components/modals/Tab.vue
@@ -0,0 +1,13 @@
+<template>
+  <div class="tabs__tab flex flex--row" :class="{'tabs__tab--active': active}" role="tab">
+    <a class="flex flex--column flex--center" href="javascript:void(0)" @click="$emit('click')">
+      <slot></slot>
+    </a>
+  </div>
+</template>
+
+<script>
+export default {
+  props: ['active'],
+};
+</script>
diff --git a/src/components/modals/TemplatesModal.vue b/src/components/modals/TemplatesModal.vue
index 3e9aa0d2..2e637a79 100644
--- a/src/components/modals/TemplatesModal.vue
+++ b/src/components/modals/TemplatesModal.vue
@@ -1,5 +1,5 @@
 <template>
-  <div class="modal__inner-1 modal__inner-1--templates">
+  <div class="modal__inner-1 modal__inner-1--templates" role="dialog" aria-label="Manage templates">
     <div class="modal__inner-2">
       <div class="form-entry">
         <label class="form-entry__label" for="template">Template</label>
diff --git a/src/components/modals/WordpressPublishModal.vue b/src/components/modals/WordpressPublishModal.vue
index b42dd913..35c03050 100644
--- a/src/components/modals/WordpressPublishModal.vue
+++ b/src/components/modals/WordpressPublishModal.vue
@@ -1,11 +1,11 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Publish to WordPress">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="wordpress"></icon-provider>
       </div>
       <p>This will publish <b>{{currentFileName}}</b> to your <b>WordPress</b> site.</p>
-      <form-entry label="Site domain">
+      <form-entry label="Site domain" error="domain">
         <input slot="field" class="textfield" type="text" v-model.trim="domain" @keyup.enter="resolve()">
         <div class="form-entry__info">
           <b>Example:</b> example.wordpress.com<br>
@@ -52,7 +52,9 @@ export default modalTemplate({
   },
   methods: {
     resolve() {
-      if (this.domain) {
+      if (!this.domain) {
+        this.setError('domain');
+      } else {
         // Return new location
         const location = wordpressProvider.makeLocation(
           this.config.token, this.domain, this.postId);
diff --git a/src/components/modals/ZendeskAccountModal.vue b/src/components/modals/ZendeskAccountModal.vue
index 3344be75..e7f8f0c7 100644
--- a/src/components/modals/ZendeskAccountModal.vue
+++ b/src/components/modals/ZendeskAccountModal.vue
@@ -1,17 +1,17 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Link Zendesk account">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="zendesk"></icon-provider>
       </div>
       <p>This will link your <b>Zendesk</b> account to your <b>StackEdit</b> workspace.</p>
-      <form-entry label="Site URL">
+      <form-entry label="Site URL" error="siteUrl">
         <input slot="field" class="textfield" type="text" v-model.trim="siteUrl" @keyup.enter="resolve()">
         <div class="form-entry__info">
           <b>Example:</b> https://example.zendesk.com/
         </div>
       </form-entry>
-      <form-entry label="Client Unique Identifier">
+      <form-entry label="Client Unique Identifier" error="clientId">
         <input slot="field" class="textfield" type="text" v-model.trim="clientId" @keyup.enter="resolve()">
         <div class="form-entry__info">
           You have to configure an OAuth Client with redirect URL <b>{{redirectUrl}}</b><br>
@@ -40,9 +40,17 @@ export default modalTemplate({
   },
   methods: {
     resolve() {
+      if (!this.siteUrl) {
+        this.setError('siteUrl');
+      }
+      if (!this.clientId) {
+        this.setError('clientId');
+      }
       if (this.siteUrl && this.clientId) {
         const parsedUrl = this.siteUrl.match(/^https:\/\/([^.]+)\.zendesk\.com/);
-        if (parsedUrl) {
+        if (!parsedUrl) {
+          this.setError('siteUrl');
+        } else {
           this.config.resolve({
             subdomain: parsedUrl[1],
             clientId: this.clientId,
diff --git a/src/components/modals/ZendeskPublishModal.vue b/src/components/modals/ZendeskPublishModal.vue
index 4211c6cd..5a8461ec 100644
--- a/src/components/modals/ZendeskPublishModal.vue
+++ b/src/components/modals/ZendeskPublishModal.vue
@@ -1,11 +1,11 @@
 <template>
-  <div class="modal__inner-1">
+  <div class="modal__inner-1" role="dialog" aria-label="Publish to Zendesk">
     <div class="modal__inner-2">
       <div class="modal__image">
         <icon-provider provider-id="zendesk"></icon-provider>
       </div>
       <p>This will publish <b>{{currentFileName}}</b> to your <b>Zendesk Help Center</b>.</p>
-      <form-entry label="Section ID">
+      <form-entry label="Section ID" error="sectionId">
         <input slot="field" class="textfield" type="text" v-model.trim="sectionId" @keyup.enter="resolve()">
         <div class="form-entry__info">
           https://example.zendesk.com/hc/en-us/sections/<b>21857469</b>-Section-name
@@ -57,7 +57,9 @@ export default modalTemplate({
   },
   methods: {
     resolve() {
-      if (this.sectionId || this.articleId) {
+      if (!this.sectionId && !this.articleId) {
+        this.setError('sectionId');
+      } else {
         // Return new location
         const location = zendeskProvider.makeLocation(
           this.config.token, this.sectionId, this.locale || 'en-us', this.articleId);
diff --git a/src/components/modals/modalTemplate.js b/src/components/modals/modalTemplate.js
index 8745b0d0..a2ba5017 100644
--- a/src/components/modals/modalTemplate.js
+++ b/src/components/modals/modalTemplate.js
@@ -4,7 +4,12 @@ import store from '../../store';
 export default (desc) => {
   const component = {
     ...desc,
+    data: () => ({
+      ...desc.data ? desc.data() : {},
+      errorTimeouts: {},
+    }),
     components: {
+      ...desc.components || {},
       FormEntry,
     },
     computed: {
@@ -19,6 +24,16 @@ export default (desc) => {
     methods: {
       ...desc.methods || {},
       openFileProperties: () => store.dispatch('modal/open', 'fileProperties'),
+      setError(name) {
+        clearTimeout(this.errorTimeouts[name]);
+        const formEntry = this.$el.querySelector(`.form-entry[error=${name}]`);
+        if (formEntry) {
+          formEntry.classList.add('form-entry--error');
+          this.errorTimeouts[name] = setTimeout(() => {
+            formEntry.classList.remove('form-entry--error');
+          }, 1000);
+        }
+      },
     },
   };
   Object.keys(desc.computedLocalSettings || {}).forEach((key) => {
diff --git a/src/libs/cledit.js b/src/libs/cledit.js
index 966e11f2..fd052beb 100644
--- a/src/libs/cledit.js
+++ b/src/libs/cledit.js
@@ -1,4 +1,4 @@
-import 'clunderscore';
+import './clunderscore';
 import cledit from './cleditCore';
 import './cleditHighlighter';
 import './cleditKeystroke';
diff --git a/src/libs/clunderscore.js b/src/libs/clunderscore.js
index d6667167..0271f6b3 100644
--- a/src/libs/clunderscore.js
+++ b/src/libs/clunderscore.js
@@ -59,6 +59,10 @@ liveCollectionProperties.cl_map = function (cb) {
     return slice.call(this).cl_map(cb)
 }
 
+liveCollectionProperties.cl_filter = function (cb) {
+    return slice.call(this).cl_filter(cb)
+}
+
 liveCollectionProperties.cl_reduce = function (cb, memo) {
     return slice.call(this).cl_reduce(cb, memo)
 }
diff --git a/src/services/localDbSvc.js b/src/services/localDbSvc.js
index c0c4f781..4564be31 100644
--- a/src/services/localDbSvc.js
+++ b/src/services/localDbSvc.js
@@ -107,9 +107,6 @@ const localDbSvc = {
       this.connection.createTx((tx) => {
         this.readAll(tx, (storeItemMap) => {
           this.writeAll(storeItemMap, tx);
-          if (!store.state.ready) {
-            store.commit('setReady');
-          }
           resolve();
         });
       }, () => reject(new Error('Local DB access error.')));
@@ -316,57 +313,74 @@ const ifNoId = cb => (obj) => {
 
 // Load the DB on boot
 localDbSvc.sync()
-  // And watch file changing
-  .then(() => store.watch(
-    () => store.getters['file/current'].id,
-    () => Promise.resolve(store.getters['file/current'])
-      // If current file has no ID, get the most recent file
-      .then(ifNoId(() => store.getters['file/lastOpened']))
-      // If still no ID, create a new file
-      .then(ifNoId(() => {
-        const id = utils.uid();
-        store.commit('content/setItem', {
-          id: `${id}/content`,
-          text: welcomeFile,
-        });
-        store.commit('file/setItem', {
-          id,
-          name: 'Welcome file',
-        });
-        return store.state.file.itemMap[id];
-      }))
-      .then((currentFile) => {
-        // Fix current file ID
-        if (store.getters['file/current'].id !== currentFile.id) {
-          store.commit('file/setCurrentId', currentFile.id);
-          // Wait for the next watch tick
-          return null;
+  .then(() => {
+    store.commit('setReady');
+
+    // If app was last opened 7 days ago and synchronization is off
+    if (!store.getters['data/loginToken'] &&
+      (utils.lastOpened + utils.cleanTrashAfter < Date.now())
+    ) {
+      // Clean files
+      store.getters['file/items'].forEach((file) => {
+        // If file is in the trash
+        if (file.parentId === 'trash') {
+          store.dispatch('deleteFile', file.id);
         }
-        return Promise.resolve()
-          // Load contentState from DB
-          .then(() => localDbSvc.loadContentState(currentFile.id))
-          // Load syncedContent from DB
-          .then(() => localDbSvc.loadSyncedContent(currentFile.id))
-          // Load content from DB
-          .then(() => localDbSvc.loadItem(`${currentFile.id}/content`))
-          .then(
-            // Success, set last opened file
-            () => store.dispatch('data/setLastOpenedId', currentFile.id),
-            (err) => {
-              // Failure (content is not available), go back to previous file
-              const lastOpenedFile = store.getters['file/lastOpened'];
-              store.commit('file/setCurrentId', lastOpenedFile.id);
-              throw err;
-            },
-          );
-      })
-      .catch((err) => {
-        console.error(err); // eslint-disable-line no-console
-        store.dispatch('notification/error', err);
-      }),
-    {
-      immediate: true,
-    }));
+      });
+    }
+
+    // watch file changing
+    store.watch(
+      () => store.getters['file/current'].id,
+      () => Promise.resolve(store.getters['file/current'])
+        // If current file has no ID, get the most recent file
+        .then(ifNoId(() => store.getters['file/lastOpened']))
+        // If still no ID, create a new file
+        .then(ifNoId(() => {
+          const id = utils.uid();
+          store.commit('content/setItem', {
+            id: `${id}/content`,
+            text: welcomeFile,
+          });
+          store.commit('file/setItem', {
+            id,
+            name: 'Welcome file',
+          });
+          return store.state.file.itemMap[id];
+        }))
+        .then((currentFile) => {
+          // Fix current file ID
+          if (store.getters['file/current'].id !== currentFile.id) {
+            store.commit('file/setCurrentId', currentFile.id);
+            // Wait for the next watch tick
+            return null;
+          }
+          return Promise.resolve()
+            // Load contentState from DB
+            .then(() => localDbSvc.loadContentState(currentFile.id))
+            // Load syncedContent from DB
+            .then(() => localDbSvc.loadSyncedContent(currentFile.id))
+            // Load content from DB
+            .then(() => localDbSvc.loadItem(`${currentFile.id}/content`))
+            .then(
+              // Success, set last opened file
+              () => store.dispatch('data/setLastOpenedId', currentFile.id),
+              (err) => {
+                // Failure (content is not available), go back to previous file
+                const lastOpenedFile = store.getters['file/lastOpened'];
+                store.commit('file/setCurrentId', lastOpenedFile.id);
+                throw err;
+              },
+            );
+        })
+        .catch((err) => {
+          console.error(err); // eslint-disable-line no-console
+          store.dispatch('notification/error', err);
+        }),
+      {
+        immediate: true,
+      });
+  });
 
 // Sync local DB periodically
 utils.setInterval(() => localDbSvc.sync(), 1000);
diff --git a/src/services/providers/githubProvider.js b/src/services/providers/githubProvider.js
index 10814488..13c4dbc7 100644
--- a/src/services/providers/githubProvider.js
+++ b/src/services/providers/githubProvider.js
@@ -28,17 +28,24 @@ export default providerRegistry.register({
       .catch(() => null); // Ignore error, without the sha upload is going to fail anyway
   },
   uploadContent(token, content, syncLocation) {
-    const sha = savedSha[syncLocation.id];
-    delete savedSha[syncLocation.id];
-    return githubHelper.uploadFile(
-      token,
-      syncLocation.owner,
-      syncLocation.repo,
-      syncLocation.branch,
-      syncLocation.path,
-      providerUtils.serializeContent(content),
-      sha,
-    )
+    let result = Promise.resolve();
+    if (!savedSha[syncLocation.id]) {
+      result = this.downloadContent(token, syncLocation); // Get the last sha
+    }
+    return result
+      .then(() => {
+        const sha = savedSha[syncLocation.id];
+        delete savedSha[syncLocation.id];
+        return githubHelper.uploadFile(
+          token,
+          syncLocation.owner,
+          syncLocation.repo,
+          syncLocation.branch,
+          syncLocation.path,
+          providerUtils.serializeContent(content),
+          sha,
+        );
+      })
       .then(() => syncLocation);
   },
   publish(token, html, metadata, publishLocation) {
diff --git a/src/services/providers/providerUtils.js b/src/services/providers/providerUtils.js
index 959e6691..f37a6375 100644
--- a/src/services/providers/providerUtils.js
+++ b/src/services/providers/providerUtils.js
@@ -40,6 +40,10 @@ export default {
         // Ignore
       }
     }
+    result.hash = utils.hash(utils.serializeObject({
+      ...result,
+      hash: undefined,
+    }));
     return result;
   },
 };
diff --git a/src/services/syncSvc.js b/src/services/syncSvc.js
index a7c897da..6ed01636 100644
--- a/src/services/syncSvc.js
+++ b/src/services/syncSvc.js
@@ -7,7 +7,7 @@ import mainProvider from './providers/googleDriveAppDataProvider';
 
 const lastSyncActivityKey = `${utils.workspaceId}/lastSyncActivity`;
 let lastSyncActivity;
-const getStoredLastSyncActivity = () => parseInt(localStorage[lastSyncActivityKey], 10) || 0;
+const getLastStoredSyncActivity = () => parseInt(localStorage[lastSyncActivityKey], 10) || 0;
 const inactivityThreshold = 3 * 1000; // 3 sec
 const restartSyncAfter = 30 * 1000; // 30 sec
 const autoSyncAfter = utils.randomize(60 * 1000); // 60 sec
@@ -19,13 +19,13 @@ const isSyncPossible = () => !store.state.offline &&
   (isDataSyncPossible() || hasCurrentFileSyncLocations());
 
 function isSyncWindow() {
-  const storedLastSyncActivity = getStoredLastSyncActivity();
+  const storedLastSyncActivity = getLastStoredSyncActivity();
   return lastSyncActivity === storedLastSyncActivity ||
     Date.now() > inactivityThreshold + storedLastSyncActivity;
 }
 
 function isAutoSyncReady() {
-  const storedLastSyncActivity = getStoredLastSyncActivity();
+  const storedLastSyncActivity = getLastStoredSyncActivity();
   return Date.now() > autoSyncAfter + storedLastSyncActivity;
 }
 
@@ -542,6 +542,20 @@ function requestSync() {
           return;
         }
 
+        // Determine if we have to clean files
+        const fileHashesToClean = {};
+        if (getLastStoredSyncActivity() + utils.cleanTrashAfter < Date.now()) {
+          // Last synchronization happened 7 days ago
+          const syncDataByItemId = store.getters['data/syncDataByItemId'];
+          store.getters['file/items'].forEach((file) => {
+            // If file is in the trash and has not been modified since it was last synced
+            const syncData = syncDataByItemId[file.id];
+            if (syncData && file.parentId === 'trash' && file.hash === syncData.hash) {
+              fileHashesToClean[file.id] = file.hash;
+            }
+          });
+        }
+
         // Call setLastSyncActivity periodically
         intervalId = utils.setInterval(() => setLastSyncActivity(), 1000);
         setLastSyncActivity();
@@ -549,6 +563,7 @@ function requestSync() {
           clearInterval(intervalId);
           cb(res);
         };
+
         Promise.resolve()
           .then(() => {
             if (isDataSyncPossible()) {
@@ -562,6 +577,15 @@ function requestSync() {
             }
             return null;
           })
+          .then(() => {
+            // Clean files
+            Object.keys(fileHashesToClean).forEach((fileId) => {
+              const file = store.state.file.itemMap[fileId];
+              if (file && file.hash === fileHashesToClean[fileId]) {
+                store.dispatch('deleteFile', fileId);
+              }
+            });
+          })
           .then(cleaner(resolve), cleaner(reject));
       }
     };
diff --git a/src/services/utils.js b/src/services/utils.js
index 817c78ae..3c2a32a3 100644
--- a/src/services/utils.js
+++ b/src/services/utils.js
@@ -24,6 +24,7 @@ window.document.addEventListener('touchstart', setLastActivity);
 // For isWindowFocused
 let lastFocus;
 const lastFocusKey = `${workspaceId}/lastWindowFocus`;
+const lastOpened = parseInt(localStorage[lastFocusKey], 10) || 0;
 const setLastFocus = () => {
   lastFocus = Date.now();
   localStorage[lastFocusKey] = lastFocus;
@@ -39,6 +40,8 @@ export default {
   workspaceId,
   origin,
   oauth2RedirectUri: `${origin}/oauth2/callback`,
+  lastOpened,
+  cleanTrashAfter: 7 * 1000, // 7 days
   types: [
     'contentState',
     'syncedContent',
diff --git a/src/store/index.js b/src/store/index.js
index 64e8714a..79797898 100644
--- a/src/store/index.js
+++ b/src/store/index.js
@@ -56,6 +56,18 @@ const store = new Vuex.Store({
       }
       return Promise.resolve();
     },
+    deleteFile({ getters, commit }, fileId) {
+      commit('file/deleteItem', fileId);
+      commit('content/deleteItem', `${fileId}/content`);
+      commit('syncedContent/deleteItem', `${fileId}/syncedContent`);
+      commit('contentState/deleteItem', `${fileId}/contentState`);
+      getters['syncLocation/items']
+        .filter(item => item.fileId === fileId)
+        .forEach(item => commit('syncLocation/deleteItem', item.id));
+      getters['publishLocation/items']
+        .filter(item => item.fileId === fileId)
+        .forEach(item => commit('publishLocation/deleteItem', item.id));
+    },
   },
   modules: {
     contentState,