diff --git a/CHANGELOG.asciidoc b/CHANGELOG.asciidoc
index 644af7ad5..98b0b7220 100644
--- a/CHANGELOG.asciidoc
+++ b/CHANGELOG.asciidoc
@@ -27,6 +27,7 @@ Added
 - Proxy support for QtWebEngine with Qt >= 5.8
 - Support for the `content -> cookies-store`  option with QtWebEngine
 - Support for the `storage -> cache-size` option with QtWebEngine
+- Support for the HTML5 fullscreen API (e.g. youtube videos) with QtWebEngine
 
 Changed
 ~~~~~~~
diff --git a/doc/help/commands.asciidoc b/doc/help/commands.asciidoc
index 0e993b723..d6db9f350 100644
--- a/doc/help/commands.asciidoc
+++ b/doc/help/commands.asciidoc
@@ -319,8 +319,13 @@ How many pages to go forward.
 
 [[fullscreen]]
 === fullscreen
+Syntax: +:fullscreen [*--leave*]+
+
 Toggle fullscreen mode.
 
+==== optional arguments
+* +*-l*+, +*--leave*+: Only leave fullscreen if it was entered by the page.
+
 [[help]]
 === help
 Syntax: +:help [*--tab*] [*--bg*] [*--window*] ['topic']+
diff --git a/qutebrowser/browser/browsertab.py b/qutebrowser/browser/browsertab.py
index b60267829..0e6d4b009 100644
--- a/qutebrowser/browser/browsertab.py
+++ b/qutebrowser/browser/browsertab.py
@@ -94,6 +94,18 @@ class TabData:
         self.override_target = None
 
 
+class AbstractAction:
+
+    """Attribute of AbstractTab for Qt WebActions."""
+
+    def __init__(self):
+        self._widget = None
+
+    def exit_fullscreen(self):
+        """Exit the fullscreen mode."""
+        raise NotImplementedError
+
+
 class AbstractPrinting:
 
     """Attribute of AbstractTab for printing the page."""
@@ -513,6 +525,9 @@ class AbstractTab(QWidget):
         new_tab_requested: Emitted when a new tab should be opened with the
                            given URL.
         load_status_changed: The loading status changed
+        fullscreen_requested: Fullscreen display was requested by the page.
+                              arg: True if fullscreen should be turned on,
+                                   False if it should be turned off.
     """
 
     window_close_requested = pyqtSignal()
@@ -528,6 +543,7 @@ class AbstractTab(QWidget):
     shutting_down = pyqtSignal()
     contents_size_changed = pyqtSignal(QSizeF)
     add_history_item = pyqtSignal(QUrl, QUrl, str)  # url, requested url, title
+    fullscreen_requested = pyqtSignal(bool)
 
     def __init__(self, win_id, mode_manager, parent=None):
         self.win_id = win_id
@@ -548,6 +564,7 @@ class AbstractTab(QWidget):
         # self.search = AbstractSearch(parent=self)
         # self.printing = AbstractPrinting()
         # self.elements = AbstractElements(self)
+        # self.action = AbstractAction()
 
         self.data = TabData()
         self._layout = miscwidgets.WrapperLayout(self)
@@ -576,6 +593,7 @@ class AbstractTab(QWidget):
         self.zoom._widget = widget
         self.search._widget = widget
         self.printing._widget = widget
+        self.action._widget = widget
         self.elements._widget = widget
 
         self._install_event_filter()
diff --git a/qutebrowser/browser/commands.py b/qutebrowser/browser/commands.py
index b01313cc0..fc131151f 100644
--- a/qutebrowser/browser/commands.py
+++ b/qutebrowser/browser/commands.py
@@ -2069,3 +2069,24 @@ class CommandDispatcher:
         """
         if bg or tab or window or url != old_url:
             self.openurl(url=url, bg=bg, tab=tab, window=window)
+
+    @cmdutils.register(instance='command-dispatcher', scope='window')
+    def fullscreen(self, leave=False):
+        """Toggle fullscreen mode.
+
+        Args:
+            leave: Only leave fullscreen if it was entered by the page.
+        """
+        if leave:
+            tab = self._current_widget()
+            try:
+                tab.action.exit_fullscreen()
+            except browsertab.UnsupportedOperationError:
+                pass
+            return
+
+        window = self._tabbed_browser.window()
+        if window.isFullScreen():
+            window.showNormal()
+        else:
+            window.showFullScreen()
diff --git a/qutebrowser/browser/webengine/webenginesettings.py b/qutebrowser/browser/webengine/webenginesettings.py
index 9db3e9d05..2be642b17 100644
--- a/qutebrowser/browser/webengine/webenginesettings.py
+++ b/qutebrowser/browser/webengine/webenginesettings.py
@@ -164,6 +164,8 @@ def init(args):
     # https://bugreports.qt.io/browse/QTBUG-58650
     PersistentCookiePolicy().set(config.get('content', 'cookies-store'))
 
+    Attribute(QWebEngineSettings.FullScreenSupportEnabled).set(True)
+
     websettings.init_mappings(MAPPINGS)
     objreg.get('config').changed.connect(update_settings)
 
diff --git a/qutebrowser/browser/webengine/webenginetab.py b/qutebrowser/browser/webengine/webenginetab.py
index 4d5e405f4..83420dbfa 100644
--- a/qutebrowser/browser/webengine/webenginetab.py
+++ b/qutebrowser/browser/webengine/webenginetab.py
@@ -79,6 +79,17 @@ _JS_WORLD_MAP = {
 }
 
 
+class WebEngineAction(browsertab.AbstractAction):
+
+    """QtWebKit implementations related to web actions."""
+
+    def _action(self, action):
+        self._widget.triggerPageAction(action)
+
+    def exit_fullscreen(self):
+        self._action(QWebEnginePage.ExitFullScreen)
+
+
 class WebEnginePrinting(browsertab.AbstractPrinting):
 
     """QtWebEngine implementations related to printing."""
@@ -473,6 +484,7 @@ class WebEngineTab(browsertab.AbstractTab):
         self.search = WebEngineSearch(parent=self)
         self.printing = WebEnginePrinting()
         self.elements = WebEngineElements(self)
+        self.action = WebEngineAction()
         self._set_widget(widget)
         self._connect_signals()
         self.backend = usertypes.Backend.QtWebEngine
@@ -640,6 +652,12 @@ class WebEngineTab(browsertab.AbstractTab):
                     url=url_string, error="Authentication required", icon='')
                 self.set_html(error_page)
 
+    @pyqtSlot('QWebEngineFullScreenRequest')
+    def _on_fullscreen_requested(self, request):
+        # FIXME:qtwebengine do we want a setting to disallow this?
+        request.accept()
+        self.fullscreen_requested.emit(request.toggleOn())
+
     def _connect_signals(self):
         view = self._widget
         page = view.page()
@@ -653,6 +671,7 @@ class WebEngineTab(browsertab.AbstractTab):
         page.loadFinished.connect(self._on_load_finished)
         page.certificate_error.connect(self._on_ssl_errors)
         page.authenticationRequired.connect(self._on_authentication_required)
+        page.fullScreenRequested.connect(self._on_fullscreen_requested)
 
         view.titleChanged.connect(self.title_changed)
         view.urlChanged.connect(self._on_url_changed)
diff --git a/qutebrowser/browser/webkit/webkittab.py b/qutebrowser/browser/webkit/webkittab.py
index ff8534838..964ef60cc 100644
--- a/qutebrowser/browser/webkit/webkittab.py
+++ b/qutebrowser/browser/webkit/webkittab.py
@@ -52,6 +52,14 @@ def init():
     objreg.register('js-bridge', js_bridge)
 
 
+class WebKitAction(browsertab.AbstractAction):
+
+    """QtWebKit implementations related to web actions."""
+
+    def exit_fullscreen(self):
+        raise browsertab.UnsupportedOperationError
+
+
 class WebKitPrinting(browsertab.AbstractPrinting):
 
     """QtWebKit implementations related to printing."""
@@ -610,6 +618,7 @@ class WebKitTab(browsertab.AbstractTab):
         self.search = WebKitSearch(parent=self)
         self.printing = WebKitPrinting()
         self.elements = WebKitElements(self)
+        self.action = WebKitAction()
         self._set_widget(widget)
         self._connect_signals()
         self.backend = usertypes.Backend.QtWebKit
diff --git a/qutebrowser/config/configdata.py b/qutebrowser/config/configdata.py
index 6f3c08575..d08766af5 100644
--- a/qutebrowser/config/configdata.py
+++ b/qutebrowser/config/configdata.py
@@ -1549,7 +1549,8 @@ KEY_DATA = collections.OrderedDict([
     ])),
 
     ('normal', collections.OrderedDict([
-        ('clear-keychain ;; search', ['<Escape>', '<Ctrl-[>']),
+        ('clear-keychain ;; search ;; fullscreen --leave',
+            ['<Escape>', '<Ctrl-[>']),
         ('set-cmd-text -s :open', ['o']),
         ('set-cmd-text :open {url:pretty}', ['go']),
         ('set-cmd-text -s :open -t', ['O']),
@@ -1769,8 +1770,12 @@ CHANGED_KEY_COMMANDS = [
     (re.compile(r'^download-page$'), r'download'),
     (re.compile(r'^cancel-download$'), r'download-cancel'),
 
-    (re.compile(r"""^search (''|"")$"""), r'clear-keychain ;; search'),
-    (re.compile(r'^search$'), r'clear-keychain ;; search'),
+    (re.compile(r"""^search (''|"")$"""),
+        r'clear-keychain ;; search ;; fullscreen --leave'),
+    (re.compile(r'^search$'),
+        r'clear-keychain ;; search ;; fullscreen --leave'),
+    (re.compile(r'^clear-keychain ;; search$'),
+        r'clear-keychain ;; search ;; fullscreen --leave'),
 
     (re.compile(r"""^set-cmd-text ['"](.*) ['"]$"""), r'set-cmd-text -s \1'),
     (re.compile(r"""^set-cmd-text ['"](.*)['"]$"""), r'set-cmd-text \1'),
@@ -1784,7 +1789,8 @@ CHANGED_KEY_COMMANDS = [
     (re.compile(r'^scroll 50 0$'), r'scroll right'),
     (re.compile(r'^scroll ([-\d]+ [-\d]+)$'), r'scroll-px \1'),
 
-    (re.compile(r'^search *;; *clear-keychain$'), r'clear-keychain ;; search'),
+    (re.compile(r'^search *;; *clear-keychain$'),
+        r'clear-keychain ;; search ;; fullscreen --leave'),
     (re.compile(r'^clear-keychain *;; *leave-mode$'), r'leave-mode'),
 
     (re.compile(r'^download-remove --all$'), r'download-clear'),
diff --git a/qutebrowser/mainwindow/mainwindow.py b/qutebrowser/mainwindow/mainwindow.py
index 069c5c6b8..9606585e1 100644
--- a/qutebrowser/mainwindow/mainwindow.py
+++ b/qutebrowser/mainwindow/mainwindow.py
@@ -456,6 +456,10 @@ class MainWindow(QWidget):
         tabs.cur_url_changed.connect(status.url.set_url)
         tabs.cur_link_hovered.connect(status.url.set_hover_url)
         tabs.cur_load_status_changed.connect(status.url.on_load_status_changed)
+        tabs.page_fullscreen_requested.connect(
+            self._on_page_fullscreen_requested)
+        tabs.page_fullscreen_requested.connect(
+            status.on_page_fullscreen_requested)
 
         # command input / completion
         mode_manager.left.connect(tabs.on_mode_left)
@@ -463,6 +467,13 @@ class MainWindow(QWidget):
             completion_obj.on_clear_completion_selection)
         cmd.hide_completion.connect(completion_obj.hide)
 
+    @pyqtSlot(bool)
+    def _on_page_fullscreen_requested(self, on):
+        if on:
+            self.showFullScreen()
+        else:
+            self.showNormal()
+
     @cmdutils.register(instance='main-window', scope='window')
     @pyqtSlot()
     def close(self):
@@ -474,14 +485,6 @@ class MainWindow(QWidget):
         """
         super().close()
 
-    @cmdutils.register(instance='main-window', scope='window')
-    def fullscreen(self):
-        """Toggle fullscreen mode."""
-        if self.isFullScreen():
-            self.showNormal()
-        else:
-            self.showFullScreen()
-
     def resizeEvent(self, e):
         """Extend resizewindow's resizeEvent to adjust completion.
 
diff --git a/qutebrowser/mainwindow/statusbar/bar.py b/qutebrowser/mainwindow/statusbar/bar.py
index 21e0d46ea..eaf8e6ffc 100644
--- a/qutebrowser/mainwindow/statusbar/bar.py
+++ b/qutebrowser/mainwindow/statusbar/bar.py
@@ -46,6 +46,8 @@ class StatusBar(QWidget):
         _hbox: The main QHBoxLayout.
         _stack: The QStackedLayout with cmd/txt widgets.
         _win_id: The window ID the statusbar is associated with.
+        _page_fullscreen: Whether the webpage (e.g. a video) is shown
+                          fullscreen.
 
     Class attributes:
         _prompt_active: If we're currently in prompt-mode.
@@ -143,6 +145,7 @@ class StatusBar(QWidget):
 
         self._win_id = win_id
         self._option = None
+        self._page_fullscreen = False
 
         self._hbox = QHBoxLayout(self)
         self.set_hbox_padding()
@@ -193,7 +196,7 @@ class StatusBar(QWidget):
     def maybe_hide(self):
         """Hide the statusbar if it's configured to do so."""
         hide = config.get('ui', 'hide-statusbar')
-        if hide:
+        if hide or self._page_fullscreen:
             self.hide()
         else:
             self.show()
@@ -306,6 +309,11 @@ class StatusBar(QWidget):
                         usertypes.KeyMode.yesno]:
             self.set_mode_active(old_mode, False)
 
+    @pyqtSlot(bool)
+    def on_page_fullscreen_requested(self, on):
+        self._page_fullscreen = on
+        self.maybe_hide()
+
     def resizeEvent(self, e):
         """Extend resizeEvent of QWidget to emit a resized signal afterwards.
 
diff --git a/qutebrowser/mainwindow/tabbedbrowser.py b/qutebrowser/mainwindow/tabbedbrowser.py
index d65360359..27a882dc7 100644
--- a/qutebrowser/mainwindow/tabbedbrowser.py
+++ b/qutebrowser/mainwindow/tabbedbrowser.py
@@ -98,6 +98,7 @@ class TabbedBrowser(tabwidget.TabWidget):
     resized = pyqtSignal('QRect')
     current_tab_changed = pyqtSignal(browsertab.AbstractTab)
     new_tab = pyqtSignal(browsertab.AbstractTab, int)
+    page_fullscreen_requested = pyqtSignal(bool)
 
     def __init__(self, win_id, parent=None):
         super().__init__(win_id, parent)
@@ -199,6 +200,9 @@ class TabbedBrowser(tabwidget.TabWidget):
             functools.partial(self.on_window_close_requested, tab))
         tab.new_tab_requested.connect(self.tabopen)
         tab.add_history_item.connect(objreg.get('web-history').add_from_tab)
+        tab.fullscreen_requested.connect(self.page_fullscreen_requested)
+        tab.fullscreen_requested.connect(
+            self.tabBar().on_page_fullscreen_requested)
 
     def current_url(self):
         """Get the URL of the current tab.
diff --git a/qutebrowser/mainwindow/tabwidget.py b/qutebrowser/mainwindow/tabwidget.py
index c639c293f..ce9a90f4d 100644
--- a/qutebrowser/mainwindow/tabwidget.py
+++ b/qutebrowser/mainwindow/tabwidget.py
@@ -259,6 +259,8 @@ class TabBar(QTabBar):
     Attributes:
         vertical: When the tab bar is currently vertical.
         win_id: The window ID this TabBar belongs to.
+        _page_fullscreen: Whether the webpage (e.g. a video) is shown
+                          fullscreen.
     """
 
     def __init__(self, win_id, parent=None):
@@ -269,6 +271,7 @@ class TabBar(QTabBar):
         config_obj = objreg.get('config')
         config_obj.changed.connect(self.set_font)
         self.vertical = False
+        self._page_fullscreen = False
         self._auto_hide_timer = QTimer()
         self._auto_hide_timer.setSingleShot(True)
         self._auto_hide_timer.setInterval(
@@ -296,20 +299,24 @@ class TabBar(QTabBar):
         self._auto_hide_timer.setInterval(
             config.get('tabs', 'show-switching-delay'))
 
+    @pyqtSlot(bool)
+    def on_page_fullscreen_requested(self, on):
+        self._page_fullscreen = on
+        self._tabhide()
+
     def on_change(self):
         """Show tab bar when current tab got changed."""
         show = config.get('tabs', 'show')
-        if show == 'switching':
+        if show == 'switching' or self._page_fullscreen:
             self.show()
             self._auto_hide_timer.start()
 
     def _tabhide(self):
         """Hide the tab bar if needed."""
         show = config.get('tabs', 'show')
-        show_never = show == 'never'
-        switching = show == 'switching'
-        multiple = show == 'multiple'
-        if show_never or (multiple and self.count() == 1) or switching:
+        if (show in ['never', 'switching'] or
+                (show == 'multiple' and self.count() == 1) or
+                self._page_fullscreen):
             self.hide()
         else:
             self.show()
diff --git a/tests/unit/browser/test_tab.py b/tests/unit/browser/test_tab.py
index d5324e597..7ff1edbde 100644
--- a/tests/unit/browser/test_tab.py
+++ b/tests/unit/browser/test_tab.py
@@ -110,6 +110,7 @@ class Tab(browsertab.AbstractTab):
         self.search = browsertab.AbstractSearch(parent=self)
         self.printing = browsertab.AbstractPrinting()
         self.elements = browsertab.AbstractElements(self)
+        self.action = browsertab.AbstractAction()
 
     def _install_event_filter(self):
         pass
diff --git a/tests/unit/config/test_config.py b/tests/unit/config/test_config.py
index 6931866ed..0c3eda341 100644
--- a/tests/unit/config/test_config.py
+++ b/tests/unit/config/test_config.py
@@ -281,9 +281,9 @@ class TestKeyConfigParser:
             ('download-page', 'download'),
             ('cancel-download', 'download-cancel'),
 
-            ('search ""', 'clear-keychain ;; search'),
-            ("search ''", 'clear-keychain ;; search'),
-            ("search", 'clear-keychain ;; search'),
+            ('search ""', 'clear-keychain ;; search ;; fullscreen --leave'),
+            ("search ''", 'clear-keychain ;; search ;; fullscreen --leave'),
+            ("search", 'clear-keychain ;; search ;; fullscreen --leave'),
             ("search ;; foobar", None),
             ('search "foo"', None),
 
@@ -305,11 +305,16 @@ class TestKeyConfigParser:
             ('scroll 0 0', 'scroll-px 0 0'),
             ('scroll 23 42', 'scroll-px 23 42'),
 
-            ('search ;; clear-keychain', 'clear-keychain ;; search'),
-            ('search;;clear-keychain', 'clear-keychain ;; search'),
+            ('search ;; clear-keychain',
+                'clear-keychain ;; search ;; fullscreen --leave'),
+            ('search;;clear-keychain',
+                'clear-keychain ;; search ;; fullscreen --leave'),
             ('search;;foo', None),
-            ('clear-keychain ;; leave-mode', 'leave-mode'),
+            ('clear-keychain ;; search',
+                'clear-keychain ;; search ;; fullscreen --leave'),
             ('leave-mode ;; foo', None),
+            ('search ;; clear-keychain',
+                'clear-keychain ;; search ;; fullscreen --leave'),
 
             ('download-remove --all', 'download-clear'),