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What are the minimum files I need to recreate a user profile?

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  • 1 eza na nkokoso oyo
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  • Eyano yasuka ya FredMcD

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What is the minimum set of files that I can recreate a FF user profile from?

For example, the official docs say to backup/migrate a user profile by copying the whole directory, but the I'm not interested in the `Crash Reports/` directory, history or any session information.

Based on a post I saw some time ago about Thunderbird user profiles, I would expect that only a few files are actually needed (off the top of my head from the TB example, possibly `cert9.db`, `extensions.json` and `prefs.js`), but I can't find the post again now to double-check and I'm not sure how well it would apply to FF.

So, what files do I need to copy over to a new user profile to retain my:

  1. extensions and their preferences
  2. Firefox preferences
  3. bookmarks
What is the minimum set of files that I can recreate a FF user profile from? For example, the [[Back up and restore information in Firefox profiles|official docs]] say to backup/migrate a user profile by copying the whole directory, but the I'm not interested in the `Crash Reports/` directory, history or any session information. Based on [https://support.mozilla.org/en-US/questions/1366283 a post I saw some time ago] about Thunderbird user profiles, I would expect that only a few files are actually needed (off the top of my head from the TB example, possibly `cert9.db`, `extensions.json` and `prefs.js`), but I can't find the post again now to double-check and I'm not sure how well it would apply to FF. So, what files do I need to copy over to a new user profile to retain my: # extensions and their preferences # Firefox preferences # bookmarks

Solution eye eponami

Warning ! ! Only Copy the files you are told. We will avoid anything that might cause problems. Here is the list of files;

cookies: cookies.sqlite Do not bother. Cookies will be created when you return to the website. However, you will have to log in everywhere. And you may lose any settings that websites store on your computer.

extensions(add-ons, themes): it would be better to download them fresh. If you need to remember what add-ons you had, open the extensions sub-folder and look at the .xpi files


logins.json and key3.db [v58+]key4.db : These are the password files. Copy Both !

persdict.dat : custom dictionary - words you added to the dictionary

mimeTypes.rdf [v55+]handlers.json : What to do with what type of file.

places.sqlite : History and Bookmarks.

prefs.js : Your settings. Note: If you were having problems, this could be contaminated.

cert8.db [v58+]cert9.db and possibly cert_override.txt : Stores all your security certificate settings and any SSL certificates you have imported into Firefox. If removed, the cert8.db, cert9.db file will be replaced.

search.json.mozlz4 : file stores the user-installed search engines that are available in the Firefox v47+

search.sqlite file and searchplugins folder store the search engines that are available in the Firefox Search bar before Firefox v47


Copy these files from the old to the new. You may get a message that the files already exist. Choose to over-write for each file.

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Solution eye oponami

Warning ! ! Only Copy the files you are told. We will avoid anything that might cause problems. Here is the list of files;

cookies: cookies.sqlite Do not bother. Cookies will be created when you return to the website. However, you will have to log in everywhere. And you may lose any settings that websites store on your computer.

extensions(add-ons, themes): it would be better to download them fresh. If you need to remember what add-ons you had, open the extensions sub-folder and look at the .xpi files


logins.json and key3.db [v58+]key4.db : These are the password files. Copy Both !

persdict.dat : custom dictionary - words you added to the dictionary

mimeTypes.rdf [v55+]handlers.json : What to do with what type of file.

places.sqlite : History and Bookmarks.

prefs.js : Your settings. Note: If you were having problems, this could be contaminated.

cert8.db [v58+]cert9.db and possibly cert_override.txt : Stores all your security certificate settings and any SSL certificates you have imported into Firefox. If removed, the cert8.db, cert9.db file will be replaced.

search.json.mozlz4 : file stores the user-installed search engines that are available in the Firefox v47+

search.sqlite file and searchplugins folder store the search engines that are available in the Firefox Search bar before Firefox v47


Copy these files from the old to the new. You may get a message that the files already exist. Choose to over-write for each file.