Version 12.0.0

New features

• Containers appear as Firefox tab groups in the tab bar. Each container's tabs form one group, with the container's name and color. Renaming or recoloring either one updates the other, and hiding a container collapses its group. (#111, #32)
  • This is on by default. To turn it off, open the extension's settings and clear Show containers as Firefox tab groups on the General tab. Turning it off ungroups the tabs, and the tabs of collapsed groups are hidden as before.
  • While it is on, index tabs are not used.
• Temporary containers left over from an earlier session, including ones made inside a container group, are removed at startup. Organizing containers and tabs explains when temporary containers are deleted.
• New options, all off by default:
  • Sort containers by name keeps containers in name order within each container group, in the popup, the sidebar and the tab bar. (#377)
  • Hide the tab count on the toolbar button. (#281)
  • In the sidebar, list the tabs of collapsed tab groups, so collapsing a group only affects the tab bar. (#482)
• Keep This Tab Loaded in the tab context menu keeps a tab from being freed from memory, by the extension's "free memory" setting or by Firefox. (#282)
• With Sync Containers on, container groups also sync between devices, including on Firefox ESR 140.
• The popup and the sidebar highlight the container of the active tab. (#8)
• Links that other apps open can go to a container chosen by site: list the sites under Sites from other apps on the Sort Containers tab of the settings. Other links follow the existing setting for links from other apps. (#481)
• Save Tabs as Bookmarks in a container's options saves its tabs to a bookmark folder, and Open in Container on a bookmark or folder opens it in the container you pick. Firefox asks to allow bookmark access the first time. (#209, #355)
• In the popup and the sidebar, Shift-click or Ctrl-click tabs to select several, then close them or drag them to another container together. (#386)
• Keyboard shortcuts to collapse and expand the current container. They have no keys by default; set them in Firefox's add-ons manager under Manage Extension Shortcuts. (#486)

New look

• The extension's pages look like Firefox's own: they use Firefox's current design, colors, controls and icons, in light and dark mode.
• The popup, the sidebar and the "Reopen in Container" panel follow the colors of your Firefox theme. (#33)

Removed

• Tags are gone. Containers now appear as tab groups in the tab bar, which cannot show tags inside them, so containers and container groups are the one way to group tabs. Updating deletes your saved tags, and tabs keep their order inside each container.

Improvements and fixes

• Firefox 140 or later is required. Firefox for Android is not supported, because it has no containers.
• The extension's pages were rebuilt with React 19. (#174)
• Fixed a memory leak that could make Firefox stop responding. (#139)
• User-agent overrides now also apply to pages served by a service worker. (#396)
• Sites no longer see navigator.userAgentData unless a container overrides the user agent, which broke some sites and sign-in pages. (#645)
• The sidebar's close-window button asks before closing the window. (#508)
• "Edit container" works for containers without an icon, and supports the container colors of Firefox 153, including violet. (#646)
• Links from other apps no longer open twice with the "last active container" option. (#411)
• Request headers no longer pass through the extension unless a container overrides the language or user agent.
• The Chrome user-agent preset follows Chrome's two-week release cycle.
• On a new installation, closing the help no longer turns on First-Party Isolate. To turn it on, click Apply Recommended Firefox Settings in the help, or use the settings. Existing installations keep their setting.
• The help no longer asks our server whether this copy is an official build every time it opens. Click Check for Official Build to check.
• The Tab Count chart on the debugging page is drawn by the extension itself instead of a page on menhera-org.github.io, so the tab counts stay in Firefox.
• Dialogs take the keyboard focus, and Escape closes them. Pressing Enter after Close window no longer opens a second confirmation.
• The privacy policy now lists every connection the extension makes and what Firefox Sync carries.
• The Cookies page asks before clearing a container's cookies, as the popup does.
• The back, close and "close all tabs of this site" buttons, which show only an icon, now have names for tooltips and screen readers.
• The Cookies page no longer fails on data stored by sandboxed pages.
• Listings of the extension's own folders work again in Firefox 152 and later.
• With index tabs set to "always", each container gets one index tab instead of several.
• New documentation explains how to use Microsoft single sign-on in containers. (#552)
• Translation updates.
• Dependencies updates.

Download and install from: https://addons.mozilla.org/firefox/addon/container-tab-groups/