sessionstore [v56] sessionstore.jsonlz4

Type about:support<enter> in the address bar.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Linux: Under the page logo on the left side, you will see Application Basics. Under this find Profile Directory. To its right press the button Open Directory.

If you need to rescue any data from them, just move them out of the profile folder to some location where Firefox doesn't look for them. You can try to read out their contents using this tool: https://www.jeffersonscher.com/res/scrounger.html

Can I restore Friday's session?

Hi Firetastic, Could you check whether either of these are available (not hidden or grayed out):

• "3-bar" menu button > Restore Previous Session
• (menu bar) History > Restore Previous Session

If they are missing or grayed, check either:

• "Library" toolbar button > History > Recently Closed Windows (and within each restored window, Recently Closed Tabs)
• (menu bar) History > Recently Closed Windows (and within each restored window, Recently Closed Tabs)

If that doesn't help...

Firefox creates numerous session history files, but because session history is only for the immediately previous session, it is unfortunately too easy to lose it. Could you start by making a backup of your existing session history files? Here's how:

Do not exit Firefox, or if you closed it, don't re-open it.

(1) To open your profile folder...

If Firefox is still running:

You can open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" Help > 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 "Open Folder" (or "Show in Finder") button.

If Firefox is closed:

Type or paste the following into the Windows Run dialog or the system search box and press Enter to launch Windows Explorer:

%APPDATA%\Mozilla\Firefox\Profiles

In that folder, do you see a semi-randomly-named folder? If so, click into it. If you find multiple such folders, find the one that was most recently updated.

(2) Copy out session history files

In your profile folder, double-click into the sessionstore-backups folder. Save all files here to a safe location such as your Documents folder.

(3) What files did you find?

The kinds of files you may find among your sessionstore files are:

• recovery.jsonlz4: the windows and tabs in your currently live Firefox session (or, if Firefox crashed at the last shutdown and is still closed, your last session)
• recovery.baklz4: a backup copy of recovery.jsonlz4
• previous.jsonlz4: the windows and tabs in your last Firefox session
• upgrade.jsonlz4-build_id: the windows and tabs in the Firefox session that was live at the time of your last update
• various .js files from Firefox 55 or earlier

Could you take a look at what you have and the date/time of the various files to see whether you think any of them would have the missing tabs?

To preview the contents of a file, you can drag and drop it onto this page, then click Scrounge URLs: https://www.jeffersonscher.com/ffu/scrounger.html

That tool is on my site, so please let me know if it doesn't work for you.

Unfortunately the session I am looking for is gone if it is only for the immediate last session. Thanks anyway. I wish Firefox could come up with a way of keeping sessions so if you lose a tab or whatever then you can just go back to a session where you had that tab or tabs. Thanks again. How would I contact Firefox to make a suggestion to them?

Firetastic said

Unfortunately the session I am looking for is gone if it is only for the immediate last session.

The only way to know for sure is to look in the files.

I wish Firefox could come up with a way of keeping sessions so if you lose a tab or whatever then you can just go back to a session where you had that tab or tabs. Thanks again. How would I contact Firefox to make a suggestion to them?

You can submit comments and suggestions through one or more of the following links:

• Feedback: https://qsurvey.mozilla.com/s3/FirefoxInput/
• Discourse: https://discourse.mozilla.org/c/firefox-development
• Reddit: https://www.reddit.com/r/firefox/
• Twitter: https://twitter.com/firefox
• Facebook: https://www.facebook.com/Firefox

But since changes to Firefox take a long time, you also could consider add-ons such as the following:

• https://addons.mozilla.org/firefox/addon/tab-session-manager/
• https://addons.mozilla.org/firefox/addon/session-sync/

Thank you Jscher 2000 but the only files that I could really see were from today. Firefox wipes the session immediately doesn't it? The problem was last night I went to look at recently closed tabs but they were gone bar one. So no way of getting those back. I love Firefox but sometimes it frustrates me too. I had a go at what you suggested and it made sense unlike last night where I was too frustrated and angry they were gone.

Well final comment. I submitted feedback to Firefox about the above. I said they could have a feature which is like System Restore for Windows. You could roll back to when it was working etc.

Right so was playing around with the above link and in my session store back up's it has upgrade jsonlz4 from 16/11/18. This is the most recent but hasn't got the closed tabs I am looking for. It also has upgrade Jsonlz4 from 2017. So does this mean I will get the most up to date tabs eventually? I like it it is really useful. Well done on such a good website.

The upgrade file from Nov. 16th was probably when Firefox 63.0.3 was installed. It's a snapshot made "just in case" there's a major issue with recovering tabs after an upgrade. I don't think you'll find another one of those until Firefox 64.0 later this month.

Since you had the tabs open very recently, hopefully you can spot them in your history.

One other thought:

Speaking of System Restore -- don't run it! -- if Windows created a snapshot in recent days, it may have some of the missing tabs. There are two programs you can use to export files from a restore point for selective "scrounging" or restoration. Here's the rundown:

(1) Set Windows to show hidden files and folders:

https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files

(2) Download and run one of these programs:

• ShadowExplorer: http://www.shadowexplorer.com/
• System Restore Explorer: http://nicbedford.co.uk/software/systemrestoreexplorer/

Within the most recent restore point shown in the program, you can explore along this path to see whether you can find a timely shadow copy of your profile:

\Users\your-user-name\AppData\Roaming\Mozilla\Firefox\Profiles\

(3) Within your profile folder:

(A) Check for a file named sessionstore.jsonlz4 at the main level of the folder, and (B) Double-click into sessionstore-backups

Export any recent files you want to check to a convenient location such as your currently live desktop (not the desktop inside the restore point).

Did you find anything promising for possible restoration or scrounging?

Yes I saw some of my old tabs so that's good.