How in the Tech

Removing misspelled words from Firefox’s dictionary

By Adam Myers ⋅ March 10, 2010 ⋅ Tags: Firefox

As a blogger I’m quite reliant on Firefox and it’s built-in spellcheck. While not perfect, it does save me a lot of embarrassment as, let’s face it, when you get used to a crutch it’s difficult to function fully without it. Even though spellcheck wasn’t prevalent through my schooling years, in my professional life you wouldn’t think of composing anything without a quick check-through.

Firefox handles forum posting or even blogging well, but as a tech blogger a lot of the terms I use throughout the day aren’t recognized as being spelled correctly in the default Firefox dictionary. Thankfully, adding the terms is simple as right-clicking on the word in question and choosing Add to Dictionary. Unfortunately, as easy as Firefox makes it to add your own additional entries, it lacks a convenient way to remove or correct terms that were added erroneously. The actual process is straightforward enough once you know where to look, however.

1. Navigate to your Firefox profile directory. Assuming you haven’t done any customization when you installed Firefox, you’d know if you did, then you can locate the folder easily using the environment variable %APPDATA%. In your Windows Start Search box key in %APPDATA%\Mozilla\Firefox\Profiles.
2. In the resulting Explorer window you should see a folder named xxxxxxx.default – where xxxxxxx is composed of seemingly random letters and numbers. You may have a few folders here but the important one is post-pended with .default.
3. Inside the profile folder look for a file titled persdict.dat. This is the custom dictionary file for your Firefox profile.
4. Using a text editor such as Notepad or Wordpad, open the file and look for the line that contains the improperly spelled word. Delete the entire line and save the file.

Easy enough isn’t it?