Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Session Restore is once again greyed-out/unclickable, and I had a huge amount of tabs open. It will take forever to figure out what even a fraction of them were, is it possible to try to restore them some other way.

  • 8 replies
  • 0 have this problem
  • 1 view
  • Last reply by cor-el

more options

Any way to try to restore or at least get a list of what my suddenly unrestorable tabs were? I mean, aside from looking through every single item in my entire history and then trying to figure out whether I had already finished that project or not?

(I'll get old and die before I complete that.)

I had many many tabs open, in many many windows, and I discovered long ago (this is not necessarily a good thing:) that if you have the internet on your device shut off while you start firefox up, and while you session restore, though all the urls and the tabs and the windows reappear, none of the are actually loaded, they are just sitting there, and you need to reload each page/tab before the computer seems to use any ram (if that's the word) to run the page. This unfortunately allows a distractable procrastinator like me to accumulate literally thousands of unfinished tabs, which I was of course going through one by one and closing, but I had tons and tons of them open still.

When session restore suddenly no longer is an option, (it is greyed out, and not for the first time,) are there any other options?

I hear mumblings from the web that imply there may be.

such as this?

https://www.jeffersonscher.com/ffu/scrounger.html?fbclid=IwAR172UESrZ1OHwugYV0KB-4lP0etZG7IyIx1IUCNn3kFLTWgN6EuL8RWLOc

anything else? or do I have to just give up and start over? (and ON that note, how can I avoid this in the future, there must be some way in lieu of me actually finishing one thing before starting 100 more,) to avoid this?

p.s. getting them back, somehow, would be what I desire, first.

Any way to try to restore or at least get a list of what my suddenly unrestorable tabs were? I mean, aside from looking through every single item in my entire history and then trying to figure out whether I had already finished that project or not? (I'll get old and die before I complete that.) I had many many tabs open, in many many windows, and I discovered long ago (this is not necessarily a good thing:) that if you have the internet on your device shut off while you start firefox up, and while you session restore, though all the urls and the tabs and the windows reappear, none of the are actually loaded, they are just sitting there, and you need to reload each page/tab before the computer seems to use any ram (if that's the word) to run the page. This unfortunately allows a distractable procrastinator like me to accumulate literally thousands of unfinished tabs, which I was of course going through one by one and closing, but I had tons and tons of them open still. When session restore suddenly no longer is an option, (it is greyed out, and not for the first time,) are there any other options? I hear mumblings from the web that imply there may be. such as this? https://www.jeffersonscher.com/ffu/scrounger.html?fbclid=IwAR172UESrZ1OHwugYV0KB-4lP0etZG7IyIx1IUCNn3kFLTWgN6EuL8RWLOc anything else? or do I have to just give up and start over? (and ON that note, how can I avoid this in the future, there must be some way in lieu of me actually finishing one thing before starting 100 more,) to avoid this? p.s. getting them back, somehow, would be what I desire, first.

All Replies (8)

more options

Did I already say that the option to restore session is completely greyed out, as in NOT CLICKABLE, and I am asking are there any other options?

more options

Hi Robbins, Are you saying that the menu item got disabled mid-session? Or was it disabled when you started Firefox? If it was disabled when you started Firefox, your previous session was most likely a private window.

more options

If "Restore Previous Session" is missing or grayed, it often means that Firefox already restored the session and you need to use

History > Recently Closed Windows

to get back any of the last 3 closed windows. There are some differences on Mac because Firefox on Mac can keep running even when the last window was closed. (On Windows, when you close the last window, Firefox unloads and needs to be started again.)


If you need to delve into old session history files -- for example, you might have one created at your latest update -- here are the steps:

(1) To open your profile folder...

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

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

In the first table on the page, find the Profile Folder row and click the "Open Folder" or "Show in Finder" button. This should launch a file browsing dialog.

If Finder has selected a folder with a semi-random name, like ab32w4Y5.default then double-click that to enter the actual profile folder.

(2) Copy out session history files

In your profile folder, double-click into the sessionstore-backups folder. Copy/paste the files from 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

Sometimes you can tell from the last modification time which one will have your missing tabs, but not always.

Optional File Contents Preview

These compressed files are a pain to view, so I created a tool on my website to list out their contents. If you want to try that, you can drag and drop it onto the large box on the following page, then click the "Scrounge URLs" button:

https://www.jeffersonscher.com/ffu/scrounger.html

If you don't get a list within 15 seconds, that probably means the script is caught in a loop. You may need to close the tab to avoid a tab crash and then try again in a new tab.

If you get a useful list, use the "Save List" button to archive it as a web page of clickable links for future reference, in case no other approach is successful.

more options

For the future, there are some add-on session managers which can save tabs in an add-on database or in your bookmarks. These capture the current URL and don't have the full tab history, but it probably would be a good fallback for these occasional problems -- assuming you remember to trigger a backup.

I haven't looked up what is good/best these days, but here's my list from 2021 of the ones that have been around for a while:

Use database storage:

Use bookmark storage:

Bookmark storage is more robust in that Firefox backs it up regularly. However, having the extra data show up when you are searching your bookmarks may be annoying.

more options

jscher2000- very interesting, I did as you suggested, and yet now that I have found the recovery, recovery backup, update, and previous files,

1. why is the previous file from january of this year? (I am guessing that was when the last session in fact began,) and 2. as this session was 6 months (is that long?) long... might it take more than 15 seconds to work? (Just wondering how long it might take to make a list if the session was 180 days. (I am assuming that most peoples' sessions are shorter and that "15 seconds to make a useful list" is based on what is typical, not on my more extreme disorganized ways. (I am if you have not guessed, a disorganized person who tends to finish one task while beginning a hundred others, every single day, often several times a day (see above/6 month session.)

more options

I literally had 28,000 *yes, I know...* tabs open on at least one occasion in the past (if you shut off the wifi connection while starting up your device... it DOES remember all the tabs, but they aren't "actively loaded" until you manually click on each one.... this seems to cause them to take up almost no space at all... hence me procrastinating to long that I eventually had 28,000 loaded (no wonder they crashed eventually, even if it took almost a year.) (this has in fact happened to me several times.)

I mention this cause I am wondering if the session was tens of thousands of tabs and 6 months long, will it take more than 15 seconds to produce a useful list?

more options

Okay, I generally test with about 100-120 tabs. I've never tested with 28,000 tabs and I suspect that would choke the script. You can let it run as long as you want if you don't mind the tab crash.

When you load a session history file into the page, the script should decompress the file and drop its contents into the textbox. The expectation is that the text is tightly packed, but looks like regular keyboard characters. If you have question mark diamonds or other random control characters, then the file did not decompress successfully.

Assuming it decompressed okay, you could use the "Save uncompressed JSON" button to save out the box contents as a file. Then you could use a JSON editor or other more sophisticated tool to extract the URLs. There would be more than 1 URL per tab because the file has the back-forward history of each tab plus up to 25 recently closed tabs per window and up to 3 closed windows (or more if you adjusted these parameters).

more options

You can try to decompress the sessionstore file in the Browser Console with the code I posted in this reply.

You need to enable the command line in the console, see: