Below are the steps on how you can remove any word that is added to the Firefox dictionary. Removing words from the Firefox dictionary can be helpful for those times you may add an incorrectly spelled word to the Firefox dictionary.

Microsoft Windows users

  • Click Start, Run, and type: %APPDATA% and press Enter.
  • In the Application Data window, open the Mozilla > Firefox > Profiles folder.
  • In the Profiles folder, there should be a “xxxxxxxx.default” folder, where “xxxxxxxx” could be something such as “yicjwewa”. Open this folder.
  • Right-click the persdict.dat file and select the Open with option.
  • Select a program from the list to open the file. We recommend selecting Notepad or WordPad as the program to open the file. If you have another text editor, this can also be used.
  • Locate the misspelled word and delete it. Make sure to also to delete the line it was on and don’t leave an empty line.

Apple users

  • Open the ~/Library/Application Support/Firefox/Profiles path.
  • In the Profiles folder, there should be a “xxxxxxxx.default” directory, where “xxxxxxxx” could be something such as “yicjwewa”. Open this directory.
  • Edit the persdict.dat file and delete the misspelled word. Make sure to also to delete the line it was on and don’t leave an empty line.
  • See our spell checker definition for further information and related links.
  • Firefox help and support.