Tab Settings
Theme settings are accessible via the
about:config
page. Typeultima
oruser.theme
to get started.
Tab positioning
This is not a "setting" but an "action" that some users may find helpful. To quickly switch between vertical or horizontal tabs
- Right click any toolbar ->
Turn on/off Vertical Tabs
- Or open the
Settings Sidebar
->Turn on/off Vertical Tabs
Autohide vertical tabs
This is not a "setting" but an "action" that some users may find helpful. To autohide the vertical tab bar
- Open the
Settings Sidebar
-> Turn onExpand sidebar on hover
ultima.tabs.belowURLbar
When using horizontal tabs, toggle between tabs on top, or tabs under the urlbar

ultima.tabs.closetabbutton.on.icon
Hovering over a tabs icon will present the "close tab" button
ultima.disable.alltabs.button
This hides the all tabs
button that is always on the Navigation Bar
ultima.spacing.compact.tabs
This reduces the spacing between vertical tabs, you can see more tabs on your screen at once
ultima.tabs.disable.update.dot
to hide the update dot that appears on unselected tabs
ultima.tabs.always.show.pinned
to force the pinned tab container to always show all pinned tabs
ultima.tabs.multiline.labels
Tabs can span multiple lines. This setting is a personal favorite. Only works with vertical tabs.
ultima.tabs.reverse.content.order
This setting simply reverses the order in which things appear in a tab. Close button first, label second, icon last. Here's an example of it in action, with multiline tabs.
user.theme.xtras.tab.outline.color
You can specify a tab outline color by typing in a color (or gradient). Leave empty for no outline.
ultima.tabs.not.a.progress.bar
This setting simulates the tab loading strip you see on some websites like youtube, reddit, etc. It isn't actually a loading bar but it's consistent, and works by tracking the loading favicon for the loading/selected tab.
ultima.tabs.vertical.hide (hiding the vertical tab bar)
ultima.tabs.vertical.hide
will hide vertical tabs completely (great for Sidebery setups)
- when combined with
ultima.tabs.vertical.hide.in.screencorner
, vertical tabs will be hidden at the bottom corner of the screen - or combined with
ultima.tabs.vertical.hide.in.screenedge
, vertical tabs will be hidden in the screen edge
For stability, ultima.tabs.vertical.hide
is reliant on ExpandonHover being ON
. This allows a consistent experience across the browser, whether in private browsing, or a different OS.
If you're interested in a Sidebery configuration be sure to check out the documentation here
ultima.tabs.newtabbutton.ontop
when using with vertical tabs, you can change the positioning of the new tab button with ultima.tabs.newtabbutton.ontop.1
and ultima.tabs.newtabbutton.ontop.2
- at the absolute top of all tabs
- at the top of tabs, under pinned tabs
ultima.tabs.tabgroups
Tab groups are styled in two seperate ways. Choose only one label style.
- tabgroups.label.1 is a circular style
- tabgroups.label.2 is a compact pill style label
- tabgroups.label.3 is an arrow dropdown style

Tab group backgrounds are more flexible. They can be used seperately or combined.
- tabgroups.background.1 is a full tab group colored background
- tabgroups.background.2 is an animated gradient background
- tabgroups.background.3 is the default tab group line background
- tabgroups.background.4 seperates the tabs in a dotted border

ultima.xstyle.containertabs
You can choose one style for container tabs with: ultima.xstyle.containertabs.i
(i, ii, iii)
ultima.tabs.vertical.hide.the.bottom.button
hide.the.bottom.button
will hide all action buttons at the bottom of vertical tabs (except for Settings)hide.the.bottom.buttons.off.hover
will hide all action buttons (except for Settings) until you hover over the vertical tabs