Somehow lost ALL my windows and tabs!

It pisses me off.

Doesn't work at all. This extension is useless and can't save any session. Doesn't support private windows and GUI is buggy.
I don't get it what you have updated there 3 months ago, but it simply doesn't work.

TL;DR The extension current state as of 11-Jul-24 is slow, functionally insufficient, visually unappealing, & Unreliable.

Session Boss is a poorly executed session manager that hinders user experience due to performance bottlenecks, feature deficiencies, and an outdated design & interface. infact it's a prime e.g. why people flee to better tab managing browsers ecosystems (chromium native support for tab management is not great but the extension support to manipulate the behavior makes up for it)

The extension's performance issues are particularly egregious when dealing with large numbers of tabs. A session with 1,500 tabs took over 30 agonizing minutes to restore using Session Boss. In contrast, Firefox's native solution (about:sessionrestore) accomplished the same feat in mere seconds. takes a minute or 2 to completely do its job of restoring the tabs with their associated groups in the tree style tab with no laggy experience at all. Otherwise it does what it suppose to do. backs up your tabs & its structure by both on schedule & change basis but in order to do that it consumes too much CPU making your browsing miserable. i.e. not optimized for a session manager.

Furthermore, the extension's performance woes extend beyond session restoration. General browsing becomes sluggish, and video playback is plagued by stuttering and lag. & worse it makes tree style tab slow & laggy. which makes it even more frustrating.


Session Boss boasts a feature set that can only be described as rudimentary. It's as if the developer took a core concept and then deliberately stripped it down to its bare bones.
- Basic Operations: The extension lacks fundamental capabilities like selecting multiple tabs for moving, copying, cutting, pasting tabs between sessions, and merging or splitting sessions. These are essential functions for any modern session manager.

-- Duplicate Tabs: Identifying and managing duplicate tabs is a nightmare. There's no built-in mechanism to distinguish between identical tabs, let alone group or remove them.

-- Import/Export: A critical omission is the absence of robust import/export options. The extension cannot import session data from popular alternatives like Chrome's TabXpert or Firefox's Tab Session Manager, nor can it utilize Firefox's native backup files (.jsonlz4, .baklz4). also, Non-existent CSV support. This limitation hampers user experience and restricts data transfer capabilities. & also significantly reduces the extension's utility.

- Organization: Session Boss offers no tools for organizing tabs within a session. There's no option to sort tabs by domain, URL, title, or most recently used. After searching for tabs, there is no way to select and manage multiple tabs across different sessions. This makes managing large numbers of tabs an exercise in frustration.


Coming down to the user interface of Session Boss is outdated and visually unappealing as already said above. It clashes with Firefox's modern design language, creating a jarring and unprofessional look. The extension's slow response times (specifically when deleting the sessions) exacerbate the overall poor user experience. I suggest the Dev. to take a look at partizion.io & tabXpert both of them are great session manager & tab manager in every way. Performance wise, UI/UX wise, Feature Wise, Support wise. plz give them a look.

Data Loss: The extension exhibited alarming instability during testing. In one instance, all saved sessions were mysteriously deleted after a system crash. This is an unacceptable level of unreliability for a session manager. Session Boss's on-change basis and scheduled saving functions conflict, causing delays and additional issues. Re-enabling the extension after disabling it resulted in losing all session data & making the extension unresponsive.


As it stands, this extension is in its infancy and requires extensive work before it can be considered a viable session manager for daily use.

Used to work fine until it randomly decided to wipe all my tabs. Nothing could be recovered. Stay away!

Used to work ok but today ALL my saved user sessions simply vanished. With no apparent means to recover them. Thousands of tabs lost.

Was working OK for the most part. Sometimes would randomly lose sessions. But now it seems dead. Clicking the icon brings up an empty menu frame. And FF addons page says it needs containered tabs and asks to delete it, with no info on what containered tabs are or how to activate it....

Don't trust this app!

It used to work fine - until today: woke up with my computer having crashed and suddenly NO session was shown in Session Boss to be recovered anymore. Not one from last night, not even a single one from the months and weeks before. I had about 150 tabs open for work and they are now ALL lost!!!!

PS: I cannot even save a new session anymore now, something seems to be completely broken with this plugin... (v 2.11.2)

Sometimes it worked well for a long time, but always took a long time to start up, and then sometimes the session was lost. And then recently it failed to restore a whole session, but only a partial one. So since the Firefox setting "Open previous windows and tabs" works well, and is also very fast, I deactivated Session Boss, which is no longer the Boss for me.

Another session extension that I can't actually work out how to actually create a session! None of the buttons do anything except the hamburger menu top right and that doesn't have a "save session" entry.

Saves tab titles. When you click on a tab in a restored session, the URL is nowhere, no page is loaded. USELESS!

Does not work in fennec android

Using FFNightly (69.0a1 (2019-06-21) (64-bit)), last updated some seconds ago, I get: "This add-on requires a newer version of Firefox (at least version 63.0). You are using Firefox 52.0." Thats really not what I expected. :-(
The version test should perhaps allow for Developer an Nightly versions, too?

After half year of using this manager, i've simply lost everything after firefox auto update

Works. Once. After the second restart all Windows just open on the first screen, on top of each other.

Used to work alright during testing 10months ago, doesn't appear to work at all any more. The little window opens, and there are buttons, and there's a menu pull-down--but clicks on any of the options do absolutely nothing. I've tried removing and reinstalling the add-on, and restarting FF. Nada. Using FF 56.0 still, as I don't yet have options for all my add-ons that work with the newer FF.

I cannot rate higher than one star if the code is not available for review in github somewhere. I would not recommend anyone use this extension with the code being available for review. From time to time there are extensions that are pulled because they contain malicious code. That's after so many users have been using them for some time. I am not saying that this extension contains any malicious code. Only that as a community we cannot ascertain whether it does or not until the source code is publicly available for review.

I concur with others posting about problems with this extension. The switching content between tabs, even across multiple regular and private browsing windows, is a show stopper!!!!! This extension is unusable for that reason, even though it has some other good features. I also suspect the extension is responsible for reversing the order of tabs on Firefox startup, another very annoying problem! I might consider reinstalling the extension if these problems are fixed and the author adds the ability to delete individual tabs prior to restoring windows.

http://forums.mozillazine.org/viewtopic.php?f=38&t=3041078&p=14805909#p14805909

I can't find a manual for instructions. How do you rename a saved session? I see some meantion of groups too. But I don't know how that's done either. Instructions would be handy about now!

FORGET IT. Another worth add-on. Closest but "no cigar".
No language, All symbols which are not universal,
NO real Instructions how to RESTORE....
Says will do "magic" but does not tell you where, how to save, how to restore.....
HOW TO RETRIEVE OR REUSE.
and assumes you only have ONE PAGE OPEN.
I have sometimes 10-12 pages open for different projects but appears BOSS only knows about ONE PAGE/SESSION. One of my pages/session has 194 tabs and it seems to save one page but ignores the other 10 pages I need the BOSS to save the tabs for.

Keep looking, this one isnt "it" either. TOO simple, does very little.

I guess for 1 or 2 tabs is ok but why not just bookmark them. What we need is the SESSION MANAGER which Mozilla obsoleted. TOTAL CONTROL by the user, save each open page, hundreds of tabs.....

Terrible POS app/extension. This thing will save your session and all tabs but will mix up all the URLs to your tabs so if you use it write them all down. I just spent 2 house getting all my tabs in my windows back since this thing saved whatever URL it wanted in each of my tabs. Useless crap there are much better add-ons just look. Should have zero stars as one is way too much for whatever you call this garbage.

I had 4 tabs open. Boss kept telling me session has 10+ tabs. I realized it's some earlier session FF made. I just couldn't save my session until I didn't clear all data. Then it saved my 4-tabs - double; importing session opens 2 FF windows! Of course, there is NO OPTION TO DELETE session or part of it. I just can't believe how bad this addon is.