Tab Groups will be removed in coming months. Since being introduced over 5 years ago very few users have used them, despite extensive marketing when they were first released. They are now holding Firefox back from future development. I am sure they will be re-introduced as an add-on however in the future if you want to continue using them.

Tyler, I have been using Linux (Red Hat/Fedora) with Firefox for years (and I use my laptop every day all day) and I was totally unaware of tab groups as I said. So maybe your marketing just didn't reach people? Also, if you plan to drop the groups, wouldn't it be sensible to have the add-on ready to take its place before it was dropped rather than after?

RedHat and Fedora build their own versions Firefox and they may not have promoted the Tab Groups feature as much as Mozilla did for Windows, Mac, and their Linux tar-balls. And with the 3rd party / "partner" builds Mozilla has no way of measuring the metrics of usage - I don't think the 3rd party builders enable Telemetry or they build their versions without it so there's no way for anyone to know usage for the various features in their Firefox builds Every Linux distro that I ever used over the years didn't have Telemetry available - SUSE, Fedora, Mint, and a few different Ubuntu-based distros.

Here is an add-on that is being developed for the Firefox 45 and later versions. https://github.com/Quicksaver/Tab-Groups https://addons.mozilla.org/en-US/firefox/addon/tab-groups/

OK - will there be a way to preserve existing groups when firefox is upgraded to 45? I have a dozen or so groups containing a dozen or so tabs each and I'd hate to lose them. If they will get lost, I'll start bookmarking the tabs under their group name so I can easily resurrect them.

Probably not. The About this Add-on mentions that it isn't compatible with the current Tab Groups / Panorama feature. "Bookmarks All Tabs" would be the way to go.

OK, I'll get my groups bookmarked in a way that I can recover the groups in the new add-on.

I hope that you plan to let users of this feature know that it's being removed - as I bet there will be a few disgruntled people out there if they upgrade (and if they're like me it's part of an OS update) to 45 and suddenly find they've lost their groups with no way of recovering them.

We are working on a migration plan, but there are less than 40k users of tab groups, so it is a pretty small audience

40k is small when you compare to millions, but imagine you're one of the 40k....it doesn't make you happy when you lose a facility that you use, and even worse when you lose the 'data' behind that facility and can't recover it.

Hi Steve, I spent a few minutes reading about possible migration paths. Automatically bookmarking the tabs in each tab group probably is the preferred approach, which is consistent with your instincts.

What you may also want to do is create some extra backups of the current session history file. While Firefox is running, your displayed tab group and hidden tab groups are recorded in recovery.js. When Firefox updates, it generally archives the latest version of the file "just in case". But since this file is very important for you, a weekly backup (or whatever interval makes sense to you) would provide a little extra assurance that you can recover the URLs of the missing tabs in the event of a migration problem.

To locate those files, start by opening your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Show Folder" button.

In the window that launches, scroll down and double-click into the sessionstore-backups folder. Here you typically find:

• recovery.js: the windows and tabs in your currently live Firefox session (or, if Firefox closed abnormally, your last session)
• recovery.bak: a backup copy of recovery.js
• previous.js: the windows and tabs in your last Firefox session
• upgrade.js-build_id: the windows and tabs in the Firefox session that was live at the time of your last update

During a normal shutdown, Firefox removes the recovery.js file (and recovery.bak), and saves a sessionstore.js file at the main level of the profile folder. If it's unpredictable whether Firefox will be open or closed when your backup runs, you may want to back up both files.

Note: By default, Windows hides the .js extension. To ensure that you are looking at the files I mentioned, you may want to turn off that feature. This article has the steps: http://windows.microsoft.com/en-us/windows/show-hide-file-name-extensions

I think I'll ignore the tab recovery settings (I have backups of 'good' session.js files as I lost tab groups in the past) - and just spend an hour or so going through the tabs bookmarking the individual tabs to a bookmark group named 'GROUP_blah' (as I named all the groups). Then I can just simply reopen the tabs in each group.

Thanks for all your help.