diff --git a/app/assets/javascripts/discourse/components/composer-messages.js.es6 b/app/assets/javascripts/discourse/components/composer-messages.js.es6
index cf0fdaad8fc..1ac68616f8e 100644
--- a/app/assets/javascripts/discourse/components/composer-messages.js.es6
+++ b/app/assets/javascripts/discourse/components/composer-messages.js.es6
@@ -13,7 +13,7 @@ export default Ember.Component.extend({
   _yourselfConfirm: null,
   similarTopics: null,
 
-  hidden: Ember.computed.not("composer.viewOpen"),
+  hidden: Ember.computed.not("composer.viewOpenOrFullscreen"),
 
   didInsertElement() {
     this._super();
diff --git a/app/assets/javascripts/discourse/components/composer-toggles.js.es6 b/app/assets/javascripts/discourse/components/composer-toggles.js.es6
index 918cfe2baba..e1172df2e29 100644
--- a/app/assets/javascripts/discourse/components/composer-toggles.js.es6
+++ b/app/assets/javascripts/discourse/components/composer-toggles.js.es6
@@ -4,18 +4,28 @@ export default Ember.Component.extend({
   tagName: "",
 
   @computed("composeState")
-  title(composeState) {
-    if (composeState === "draft" || composeState === "saving") {
-      return "composer.abandon";
-    }
-    return "composer.collapse";
+  toggleTitle(composeState) {
+    return composeState === "draft" || composeState === "saving"
+      ? "composer.abandon"
+      : "composer.collapse";
+  },
+
+  @computed("composeState")
+  fullscreenTitle(composeState) {
+    return composeState === "fullscreen"
+      ? "composer.exit_fullscreen"
+      : "composer.enter_fullscreen";
   },
 
   @computed("composeState")
   toggleIcon(composeState) {
-    if (composeState === "draft" || composeState === "saving") {
-      return "times";
-    }
-    return "chevron-down";
+    return composeState === "draft" || composeState === "saving"
+      ? "times"
+      : "chevron-down";
+  },
+
+  @computed("composeState")
+  fullscreenIcon(composeState) {
+    return composeState === "fullscreen" ? "compress" : "expand";
   }
 });
diff --git a/app/assets/javascripts/discourse/controllers/composer.js.es6 b/app/assets/javascripts/discourse/controllers/composer.js.es6
index 1a6bf47dd0f..8a0946c5e9d 100644
--- a/app/assets/javascripts/discourse/controllers/composer.js.es6
+++ b/app/assets/javascripts/discourse/controllers/composer.js.es6
@@ -231,7 +231,7 @@ export default Ember.Controller.extend({
 
   @computed("model.composeState", "model.creatingTopic")
   popupMenuOptions(composeState) {
-    if (composeState === "open") {
+    if (composeState === "open" || composeState === "fullscreen") {
       let options = [];
 
       options.push(
@@ -386,7 +386,10 @@ export default Ember.Controller.extend({
       ) {
         this.close();
       } else {
-        if (this.get("model.composeState") === Composer.OPEN) {
+        if (
+          this.get("model.composeState") === Composer.OPEN ||
+          this.get("model.composeState") === Composer.FULLSCREEN
+        ) {
           this.shrink();
         } else {
           this.cancelComposer();
@@ -396,6 +399,11 @@ export default Ember.Controller.extend({
       return false;
     },
 
+    fullscreenComposer() {
+      this.toggleFullscreen();
+      return false;
+    },
+
     // Import a quote from the post
     importQuote(toolbarEvent) {
       const postStream = this.get("topic.postStream");
@@ -457,7 +465,7 @@ export default Ember.Controller.extend({
         return;
       }
 
-      if (this.get("model.viewOpen")) {
+      if (this.get("model.viewOpen") || this.get("model.viewFullscreen")) {
         this.shrink();
       }
     },
@@ -881,6 +889,10 @@ export default Ember.Controller.extend({
           }
         ]);
       } else {
+        // in case the composer is
+        // cancelled while in fullscreen
+        $("html").removeClass("fullscreen-composer");
+
         // it is possible there is some sort of crazy draft with no body ... just give up on it
         this.destroyDraft();
         this.get("model").clearState();
@@ -947,6 +959,15 @@ export default Ember.Controller.extend({
     this.set("model.composeState", Composer.DRAFT);
   },
 
+  toggleFullscreen() {
+    this._saveDraft();
+    if (this.get("model.composeState") === Composer.FULLSCREEN) {
+      this.set("model.composeState", Composer.OPEN);
+    } else {
+      this.set("model.composeState", Composer.FULLSCREEN);
+    }
+  },
+
   close() {
     this.setProperties({ model: null, lastValidatedAt: null });
   },
diff --git a/app/assets/javascripts/discourse/lib/keyboard-shortcuts.js.es6 b/app/assets/javascripts/discourse/lib/keyboard-shortcuts.js.es6
index 01b9e3372e3..31f1c9a2140 100644
--- a/app/assets/javascripts/discourse/lib/keyboard-shortcuts.js.es6
+++ b/app/assets/javascripts/discourse/lib/keyboard-shortcuts.js.es6
@@ -65,6 +65,7 @@ const bindings = {
   "shift+s": { click: "#topic-footer-buttons button.share", anonymous: true }, // share topic
   "shift+u": { handler: "goToUnreadPost" },
   "shift+z shift+z": { handler: "logout" },
+  "shift+f11": { handler: "fullscreenComposer" },
   t: { postAction: "replyAsNewTopic" },
   u: { handler: "goBack", anonymous: true },
   "x r": {
@@ -212,6 +213,13 @@ export default {
     }
   },
 
+  fullscreenComposer() {
+    const composer = this.container.lookup("controller:composer");
+    if (composer.get("model")) {
+      composer.toggleFullscreen();
+    }
+  },
+
   pinUnpinTopic() {
     this.container.lookup("controller:topic").togglePinnedState();
   },
diff --git a/app/assets/javascripts/discourse/models/composer.js.es6 b/app/assets/javascripts/discourse/models/composer.js.es6
index 483bb66eef7..a86e48de2d3 100644
--- a/app/assets/javascripts/discourse/models/composer.js.es6
+++ b/app/assets/javascripts/discourse/models/composer.js.es6
@@ -26,6 +26,7 @@ const CLOSED = "closed",
   SAVING = "saving",
   OPEN = "open",
   DRAFT = "draft",
+  FULLSCREEN = "fullscreen",
   // When creating, these fields are moved into the post model from the composer model
   _create_serializer = {
     raw: "reply",
@@ -144,15 +145,24 @@ const Composer = RestModel.extend({
 
   viewOpen: Em.computed.equal("composeState", OPEN),
   viewDraft: Em.computed.equal("composeState", DRAFT),
+  viewFullscreen: Em.computed.equal("composeState", FULLSCREEN),
+  viewOpenOrFullscreen: Em.computed.or("viewOpen", "viewFullscreen"),
 
   composeStateChanged: function() {
-    var oldOpen = this.get("composerOpened");
+    let oldOpen = this.get("composerOpened"),
+      elem = $("html");
+
+    if (this.get("composeState") === FULLSCREEN) {
+      elem.addClass("fullscreen-composer");
+    } else {
+      elem.removeClass("fullscreen-composer");
+    }
 
     if (this.get("composeState") === OPEN) {
       this.set("composerOpened", oldOpen || new Date());
     } else {
       if (oldOpen) {
-        var oldTotal = this.get("composerTotalOpened") || 0;
+        let oldTotal = this.get("composerTotalOpened") || 0;
         this.set("composerTotalOpened", oldTotal + (new Date() - oldOpen));
       }
       this.set("composerOpened", null);
@@ -160,9 +170,8 @@ const Composer = RestModel.extend({
   }.observes("composeState"),
 
   composerTime: function() {
-    var total = this.get("composerTotalOpened") || 0;
-
-    var oldOpen = this.get("composerOpened");
+    let total = this.get("composerTotalOpened") || 0,
+      oldOpen = this.get("composerOpened");
     if (oldOpen) {
       total += new Date() - oldOpen;
     }
@@ -183,7 +192,7 @@ const Composer = RestModel.extend({
   // view detected user is typing
   typing: _.throttle(
     function() {
-      var typingTime = this.get("typingTime") || 0;
+      let typingTime = this.get("typingTime") || 0;
       this.set("typingTime", typingTime + 100);
     },
     100,
@@ -1041,6 +1050,7 @@ Composer.reopenClass({
   SAVING,
   OPEN,
   DRAFT,
+  FULLSCREEN,
 
   // The actions the composer can take
   CREATE_TOPIC,
diff --git a/app/assets/javascripts/discourse/templates/components/composer-toggles.hbs b/app/assets/javascripts/discourse/templates/components/composer-toggles.hbs
index 93263ae3cbe..a9efe1f6d58 100644
--- a/app/assets/javascripts/discourse/templates/components/composer-toggles.hbs
+++ b/app/assets/javascripts/discourse/templates/components/composer-toggles.hbs
@@ -10,5 +10,13 @@
     class="toggler"
     icon=toggleIcon
     action=toggleComposer
-    title=title}}
+    title=toggleTitle}}
+
+  {{#unless site.mobileView}}
+    {{flat-button
+      class="toggle-fullscreen"
+      icon=fullscreenIcon
+      action=toggleFullscreen
+      title=fullscreenTitle}}
+  {{/unless}}
 </div>
diff --git a/app/assets/javascripts/discourse/templates/composer.hbs b/app/assets/javascripts/discourse/templates/composer.hbs
index dc71db36f76..d60ed2e804d 100644
--- a/app/assets/javascripts/discourse/templates/composer.hbs
+++ b/app/assets/javascripts/discourse/templates/composer.hbs
@@ -9,73 +9,77 @@
       {{composer-messages composer=model
                           messageCount=messageCount
                           addLinkLookup="addLinkLookup"}}
-      {{#if model.viewOpen}}
+      {{#if model.viewOpenOrFullscreen}}
         <div class="reply-area {{if canEditTags 'with-tags'}}">
           <div class='composer-fields'>
             {{plugin-outlet name="composer-open" args=(hash model=model)}}
             <div class='reply-to'>
-              <div class="reply-details">
-                {{composer-action-title model=model canWhisper=canWhisper tabindex=8}}
+              {{#unless model.viewFullscreen}}
+                <div class="reply-details">
+                  {{composer-action-title model=model canWhisper=canWhisper tabindex=8}}
 
-                {{#unless site.mobileView}}
-                  {{#if whisperOrUnlistTopicText}}
-                    <span class='whisper'>({{whisperOrUnlistTopicText}})</span>
-                  {{/if}}
-                  {{#if model.noBump}}
-                    <span class="no-bump">{{d-icon "anchor"}}</span>
-                  {{/if}}
-                {{/unless}}
+                  {{#unless site.mobileView}}
+                    {{#if whisperOrUnlistTopicText}}
+                      <span class='whisper'>({{whisperOrUnlistTopicText}})</span>
+                    {{/if}}
+                    {{#if model.noBump}}
+                      <span class="no-bump">{{d-icon "anchor"}}</span>
+                    {{/if}}
+                  {{/unless}}
 
-                {{#if canEdit}}
-                  {{#link-to-input onClick=(action "displayEditReason") showInput=showEditReason key="composer.show_edit_reason" class="display-edit-reason"}}
-                    {{text-field value=editReason tabindex="7" id="edit-reason" maxlength="255" placeholderKey="composer.edit_reason_placeholder"}}
-                  {{/link-to-input}}
-                {{/if}}
-              </div>
+                  {{#if canEdit}}
+                    {{#link-to-input onClick=(action "displayEditReason") showInput=showEditReason key="composer.show_edit_reason" class="display-edit-reason"}}
+                      {{text-field value=editReason tabindex="7" id="edit-reason" maxlength="255" placeholderKey="composer.edit_reason_placeholder"}}
+                    {{/link-to-input}}
+                  {{/if}}
+                </div>
+              {{/unless}}
               {{composer-toggles composeState=model.composeState
                         toggleComposer=(action "toggle")
-                        toggleToolbar=(action "toggleToolbar")}}
+                        toggleToolbar=(action "toggleToolbar")
+                        toggleFullscreen=(action "fullscreenComposer")}}
             </div>
+            {{#unless model.viewFullscreen}}
+              {{#if model.canEditTitle}}
+                {{#if model.creatingPrivateMessage}}
+                  <div class='user-selector'>
+                    {{composer-user-selector topicId=topicModel.id
+                                             usernames=model.targetUsernames
+                                             hasGroups=model.hasTargetGroups
+                                             focusTarget=focusTarget
+                                             class="users-input"}}
+                    {{#if showWarning}}
+                      <label class='add-warning'>
+                        {{input type="checkbox" checked=model.isWarning tabindex="3"}}
+                        {{i18n "composer.add_warning"}}
+                      </label>
+                    {{/if}}
+                  </div>
+                {{/if}}
 
-            {{#if model.canEditTitle}}
-              {{#if model.creatingPrivateMessage}}
-                <div class='user-selector'>
-                  {{composer-user-selector topicId=topicModel.id
-                                           usernames=model.targetUsernames
-                                           hasGroups=model.hasTargetGroups
-                                           focusTarget=focusTarget
-                                           class="users-input"}}
-                  {{#if showWarning}}
-                    <label class='add-warning'>
-                      {{input type="checkbox" checked=model.isWarning tabindex="3"}}
-                      {{i18n "composer.add_warning"}}
-                    </label>
+                <div class="title-and-category {{if showPreview 'with-preview'}}">
+
+                  {{composer-title composer=model lastValidatedAt=lastValidatedAt focusTarget=focusTarget}}
+
+                  {{#if model.showCategoryChooser}}
+                    <div class="category-input">
+                      {{category-chooser
+                        fullWidthOnMobile=true
+                        value=model.categoryId
+                        scopedCategoryId=scopedCategoryId
+                        tabindex="3"}}
+                      {{popup-input-tip validation=categoryValidation}}
+                    </div>
+                  {{/if}}
+                  {{#if canEditTags}}
+                    {{mini-tag-chooser tags=model.tags tabindex="4" categoryId=model.categoryId minimum=model.minimumRequiredTags}}
+                    {{popup-input-tip validation=tagValidation}}
                   {{/if}}
                 </div>
               {{/if}}
 
-              <div class="title-and-category {{if showPreview 'with-preview'}}">
-
-                {{composer-title composer=model lastValidatedAt=lastValidatedAt focusTarget=focusTarget}}
-
-                {{#if model.showCategoryChooser}}
-                  <div class="category-input">
-                    {{category-chooser
-                      fullWidthOnMobile=true
-                      value=model.categoryId
-                      scopedCategoryId=scopedCategoryId
-                      tabindex="3"}}
-                    {{popup-input-tip validation=categoryValidation}}
-                  </div>
-                {{/if}}
-                {{#if canEditTags}}
-                  {{mini-tag-chooser tags=model.tags tabindex="4" categoryId=model.categoryId minimum=model.minimumRequiredTags}}
-                  {{popup-input-tip validation=tagValidation}}
-                {{/if}}
-              </div>
-            {{/if}}
-
-            {{plugin-outlet name="composer-fields" args=(hash model=model)}}
+              {{plugin-outlet name="composer-fields" args=(hash model=model)}}
+            {{/unless}}
 
           </div>
 
@@ -104,21 +108,24 @@
             {{plugin-outlet name="composer-fields-below" args=(hash model=model)}}
 
             <div class='save-or-cancel'>
-              {{composer-save-button action=(action "save")
-                                     icon=model.saveIcon
-                                     label=model.saveLabel
-                                     disableSubmit=disableSubmit}}
-            {{#if site.mobileView}}
-              <a href {{action "cancel"}} class='cancel' tabindex="6" title="{{i18n 'cancel'}}">
-                {{#if canEdit}}
-                  {{d-icon "times"}}
-                {{else}}
-                  {{d-icon "trash-o"}}
-                {{/if}}
-              </a>
-            {{else}}
-              <a href {{action "cancel"}} class='cancel' tabindex="6" >{{i18n 'cancel'}}</a>
-            {{/if}}
+              {{#unless model.viewFullscreen}}
+                {{composer-save-button action=(action "save")
+                                       icon=model.saveIcon
+                                       label=model.saveLabel
+                                       disableSubmit=disableSubmit}}
+
+              {{#if site.mobileView}}
+                <a href {{action "cancel"}} class='cancel' tabindex="6" title="{{i18n 'cancel'}}">
+                  {{#if canEdit}}
+                    {{d-icon "times"}}
+                  {{else}}
+                    {{d-icon "trash-o"}}
+                  {{/if}}
+                </a>
+              {{else}}
+                <a href {{action "cancel"}} class='cancel' tabindex="6" >{{i18n 'cancel'}}</a>
+              {{/if}}
+            {{/unless}}
 
 
               {{#if site.mobileView}}
@@ -165,7 +172,7 @@
           </div>
         </div>
 
-      {{else}}
+        {{else}}
         <div class='saving-text'>
           {{#if model.createdPost}}
             {{i18n 'composer.saved'}} <a class='permalink' href="{{unbound createdPost.url}}" {{action "viewNewReply"}}>{{i18n 'composer.view_new_post'}}</a>
@@ -183,6 +190,7 @@
         </div>
 
         {{composer-toggles composeState=model.composeState
+          toggleFullscreen=(action "fullscreenComposer")
           toggleComposer=(action "toggle")
           toggleToolbar=(action "toggleToolbar")}}
 
diff --git a/app/assets/javascripts/discourse/templates/modal/keyboard-shortcuts-help.hbs b/app/assets/javascripts/discourse/templates/modal/keyboard-shortcuts-help.hbs
index 9d5ae70e07c..58b432b06ad 100644
--- a/app/assets/javascripts/discourse/templates/modal/keyboard-shortcuts-help.hbs
+++ b/app/assets/javascripts/discourse/templates/modal/keyboard-shortcuts-help.hbs
@@ -40,6 +40,7 @@
       <h4>{{i18n 'keyboard_shortcuts_help.composing.title'}}</h4>
       <ul>
         <li>{{{i18n 'keyboard_shortcuts_help.composing.return'}}}</li>
+        <li>{{{i18n 'keyboard_shortcuts_help.composing.fullscreen'}}}</li>
         <li>{{{i18n 'keyboard_shortcuts_help.application.create'}}}</li>
         <li>{{{i18n 'keyboard_shortcuts_help.actions.reply_as_new_topic'}}}</li>
         <li>{{{i18n 'keyboard_shortcuts_help.actions.reply_topic'}}}</li>
diff --git a/app/assets/stylesheets/common/base/compose.scss b/app/assets/stylesheets/common/base/compose.scss
index 18b898a8c5b..ba0e013c8bf 100644
--- a/app/assets/stylesheets/common/base/compose.scss
+++ b/app/assets/stylesheets/common/base/compose.scss
@@ -147,7 +147,7 @@
       margin-left: auto;
       margin-right: -5px;
       button {
-        padding: 0 8px;
+        padding: 0 2px;
       }
     }
   }
diff --git a/app/assets/stylesheets/desktop/compose.scss b/app/assets/stylesheets/desktop/compose.scss
index 551b28b8b3b..21152aa007d 100644
--- a/app/assets/stylesheets/desktop/compose.scss
+++ b/app/assets/stylesheets/desktop/compose.scss
@@ -203,3 +203,53 @@
   flex-grow: 1;
   text-align: right;
 }
+
+// fullscreen composer styles
+.fullscreen-composer {
+  overflow: hidden;
+
+  .profiler-results {
+    display: none;
+  }
+  #reply-control {
+    &.fullscreen {
+      // important needed because of inline styles when height is changed manually with grippie
+      height: 100vh !important;
+      z-index: z("header") + 1;
+      .d-editor-preview-wrapper {
+        margin-top: 1%;
+      }
+      .reply-to {
+        border-bottom: 1px solid $primary-low;
+        padding-bottom: 3px;
+        margin: 0;
+        .composer-controls {
+          margin-right: 0;
+        }
+      }
+      .d-editor-textarea-wrapper {
+        border: none;
+      }
+      &.show-preview .d-editor-textarea-wrapper {
+        border-right: 1px solid $primary-low;
+      }
+      #draft-status,
+      #file-uploading {
+        margin-left: 0;
+        text-align: initial;
+      }
+      .composer-popup {
+        top: 30px;
+      }
+      &:before {
+        content: "";
+        background: $secondary;
+        width: 100%;
+        height: 100%;
+        position: fixed;
+        z-index: -1;
+        left: 0;
+      }
+    }
+  }
+}
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index 157b35bb0be..806b24ad8cf 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -1427,6 +1427,8 @@ en:
       help: "Markdown Editing Help"
       collapse: "minimize the composer panel"
       abandon: "close composer and discard draft"
+      enter_fullscreen: "enter fullscreen composer"
+      exit_fullscreen: "exit fullscreen composer"
       modal_ok: "OK"
       modal_cancel: "Cancel"
       cant_send_pm: "Sorry, you can't send a message to %{username}."
@@ -2613,6 +2615,7 @@ en:
       composing:
         title: 'Composing'
         return: '<b>shift</b>+<b>c</b> Return to composer'
+        fullscreen: '<b>shift</b>+<b>F11</b> Fullscreen composer'
       actions:
         title: 'Actions'
         bookmark_topic: '<b>f</b> Toggle bookmark topic'