How to delete or modify autocomplete entry in firefox?

We know auto complete. When we enter a username the firefox will auto complete our username.

Say some of the entries are wrong and we want to change it. How would we do so?

4 Answers

When the incorrect entry appears, highlight that entry and then press Shift + Delete and just that entry will be permanently removed.

Usually for this type of task you would use ProcessMonitor to trace hard disk drive activity in real time. Then filter PRocessMonitor by eg FireFox in this example and you can see which file (or registry key) FF is reading/writing to. Then edit the file.

I like Jeremy's way to delete an entry. But if you want to modify it, it's more complicated and needs an add-on for accessing the form history database file:

I have version 82.0 (64) running on Windows 10.

I wanted to add my experience. I accidentally typed a password right after my username on the T-mobile login page, and it saved the whole thing as an autocomplete suggestion whenever I went back to login. So there was my username, followed by the password, showing up to select, which of course makes me nervous for my browser to store that. Anyway, I did not want to clear my whole history - and looking up how to access this list landed me here. There are Firefox add-ons that allow this list to be viewed and edited - but I am very weary of any insecure add-on accessing those records.

About using the arrows to select an entry and delete it - I tried that - but the down arrow went to the next field on the web page, and automatically filled in the suggestion (there was only one). I could not select that entry to delete it. So I figured out that the UP arrow would allow me to select and delete it (I think only because there is nothing above the "username" field on the login page).

Anyway - hope that helps someone. Firefox really ought to have this autocomplete list editable within the settings just like they do addresses.

You can open the formhistory.sqlite file in something like DB Browser for SQLite.

In the moz_formhistory table, find the record with the value you want deleted in the value column. Delete the record, e.g. DELETE from moz_formhistory where value = '';

This worked for me on Firefox 84.0.2 64-bit for Windows, where the location of the sqlite file is

C:\Users\<myusername>\AppData\Roaming\Mozilla\Firefox\Profiles\<myprofilename>.default-release\formhistory.sqlite