Sorry to hear about your data loss. Do you share this computer with anyone?

There are two built-in features designed to clear history, and there are at least two other scenarios that could cause some or all history to be lost.

(1) Clear Recent History (Ctrl+Shift+Del) or the "Forget" button

These features immediately delete large amounts of history and may also clear cookies that keep you logged in to sites. It's unlikely that this would be done accidentally.

(2) Clear History When Firefox Closes

If this had been turned on, you probably would not have even a week of history, but you can check for this on the Settings page, Privacy & Security panel, History section. Select "Firefox will: Use custom settings for history" and if there is a checkmark next to "Clear history when Firefox closes" you probably want to turn that off.

(3) Refresh scenario

Firefox has a troubleshooting feature to refresh your customizations and remove add-ons. This sometimes is referred to as a tune-up to address slow startup. When you invoke this feature, Firefox creates a new folder on your Windows desktop named Old Firefox Data. If you have that folder, check inside to see how recent the contents are. Maybe something can be recovered from there.

(4) New Profile scenario

Sometimes Firefox is not able to continue using your profile folder because of a file lock or a version downgrade. In that case, Firefox usually will notify you that it is creating a new profile. If you connect the new profile to your Firefox Account, you may get some of your data through Sync, but it's usually not complete. I'll give steps below the line to check for an older profile.

(5) External cleaner scenario

Privacy/utility programs like CCleaner and Advanced SystemCare can delete browser data as part of their regularly scheduled operations. If you have any programs that do that, make sure they aren't removing important data from Firefox.

Profile Manager Page

Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

This page should list at least one profile and could list many. (Each profile has two folders and one or more buttons. Do not use any Remove buttons!)

The profile that Firefox is currently using will have this:

This is the profile in use and it cannot be deleted.

Do you have any other profile(s) listed on this page? If so, you can check whether it is the one you were using recently by clicking its Launch profile in new browser button.

If it isn't what you want, simply close that new window.

If it IS what you want, back on the about:profiles page, you can use it for occasional reference in the same way, OR you can switch your main profile to the older one by clicking the Set as default profile button for that profile so Firefox uses it automatically at the next startup.

Unfortunately, I am not aware of any method to merge the history from two profiles.

Hi,

Thank you for your reply. The only option that seemed plausible in my case is a new profile being created. Although there was a second profile, it had zero history. Then I read your reply again.

I have cats. Who walk on my keyboard. It is possible someone stepped on the keys and deleted my history. So, I have two follow-up questions:

1. How do I disable keyboard shortcuts so this doesn't happen again?

2. Is there a way to recover my deleted history?

Thank you for your time.

Cats, that's a tough one. It's definitely conceivable that a cat could Ctrl+Shift+Delete, although it would be pretty terrible luck if they did.

I can't think of a Firefox setting to lock out the keyboard in Firefox.

One possibility is to lock Windows when you step away (hold down the Windows key and tap the L key). That seems safest.

It might be sufficient to minimize all the windows when the cat could be approaching, but this could be disruptive to your workflow (hold down the Windows key and tap either D or M).

Regarding past history, if you make regular backups of your computer, you may be able to recover the places.sqlite database from your backup.

If not, Windows might have captured it at some point. Windows often makes backup copies of Firefox profile data when you do system updates, so you can use a tool like one of the following programs:

• ShadowExplorer: http://www.shadowexplorer.com/
• Shadow Copy View: https://www.nirsoft.net/utils/shadow_copy_view.html

Note that you should set Windows to show hidden files and folders before diving in:

https://support.microsoft.com/en-us/windows/show-hidden-files-0320fe58-0117-fd59-6851-9b7f9840fdb2

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

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

You could take any recent places.sqlite file and copy it to a more convenient location such as your Documents folder. Then you can point a program like the following at the file to generate a list of the file's contents and save it in a variety of formats. However, I am not aware of a way to merge the old history with the current history.

http://www.nirsoft.net/utils/mozilla_history_view.html

Did you also check for orphaned profiles on the hard drive that aren't registered in profiles.ini ?

See also:

• https://support.mozilla.org/en-US/kb/recover-user-data-missing-after-firefox-update
• https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

Hi Cor-el, I still have my bookmarks. It just seems my history was deleted. I've been so careful not to delete it all these years because I'm always going back to track sources. Ug. It's so frustrating for it to just be gone.

It is possible that there has been a places.sqlite corruption that has caused Firefox to create a new places.sqlite. In this case will the bookmarks restored automatically from a backup, but for history is there no backup (check for places.sqlite.corrupt).

How far do the backups in the bookmarkbackups folder go back ? The times.json file in a profile contains the date/time of creation in UNIX Epoch format.

You can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page (Root directory).

• Help -> More Troubleshooting Information -> Profile Folder/Directory:
  Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data