How to recover a corrupted Firefox cookies.sqlite

About a week ago, Firefox 3 would no longer seem to hold any cookies. I would log in to my regular sites and say “remember me” and yet the next time I started Firefox, I was back to square one, re-entering my information over and over. It kept losing the cookies and forgetting who I was!

This ranged from odd the first day, to strange the second, to mildly annoying the third. By the time I got into the office this morning, I was ready to reinstall but that seemed excessive so I went searching. I came across a Mozilla Support thread which identified the issue as a corrupted sqlite database in Firefox 3. The solution was to close Firefox, rename the file and start it again, effectively removing the corrupted file and starting over. That’s good but what if you want to recover your previous cookies?

Recovering your cookies

The process is fairly simple although the amount of recovery possible will vary depending on where your sqlite database is corrupt. In my case, I was able to recover about 1050 cookies which is a lot better than nothing. Here’s what you need (my examples are Windows-based):

1. Close Firefox
2. Go to your Firefox profile directory, rename cookies.sqlite to was_cookies.sqlite
3. First, confirm that a corrupted sqlite database is your problem. Restart Firefox and test by logging into a site, clicking remember me, closing FF and then opening it and going back to the site. Your freshly created cookies.sqlite should be working and you will have been automatically logged in. If not, you’re probably facing some other issue beyond the scope of this guide. Close Firefox and rename was_cookies.sqlite back to cookies.sqlite and look elsewhere. If this did work, then continue on…
4. Download the SQLite binary for your platform and extract it into your profile directory
5. Start it:

   > sqlite3.exe was_cookies.sqlite
   SQLite version 3.6.13
   Enter ".help" for instructions

6. See how many records you can retrieve before it fails: sqlite> select count(*) from moz_cookies;
7. If you want to proceed, export the cookies:

   sqlite> .mode insert moz_cookies
   sqlite> .output was_cookies_insert_sql
   sqlite> select * from moz_cookies;
   SQL error: database disk image is malformed
   sqlite> .quit

8. Now load the current cookies.sqlite file and import your saved cookies:

   > sqlite3.exe cookies.sqlite
   SQLite version 3.6.13
   Enter ".help" for instructions
   Enter SQL statements terminated with a ";"
   sqlite> .read was_cookies_insert_sql
   sqlite> select count(*) from moz_cookies;
   1058
   sqlite> .quit

9. Ok, you should be good to go. Restart Firefox 3 and try going back to your sites. Remember, it probably didn’t recover all of them so it’s quite likely at least some of the sites that used to log you in automatically or store your preferences will no longer be in your cookies.

Hope that helps!