Making sure that your installation of Firefox spell checks in British English is vitally important on this wiki, since British spellings are required. However, the British spell checking add-on for Firefox is incomplete, which makes Firefox an unsuitable browser for those who intend to actually edit this wiki.

This tutorial explains how to instal Mark Tyndall's British English Dictionary add on, version 1.19.1 into Firefox 14.0.1. The following instructions were verified as working in Firefox 14.0.1 for Mac. However, since the add-on is platform neutral, this tutorial applies to Windows and Linux users, too.

If you have a version lower than 14.0.1, you can still follow this installation guide, but you will want to instal version 1.19(.0) of the Mark Tyndall add-on, instead, which can be found here.

However, we strongly recommend that if you have a Mac, you should only edit in Safari. This Firefox fix is not nearly as good as Safari's British spell checking abilities.


  1. Go to any page here at that you have permission to edit
  2. Choose to edit the page
  3. Right click anywhere in the editing pane and pull down to Languages. Slide over to look at your installed dictionaries. If you have a British dictionary installed chose it: you're done! If not, proceed to the next step.
  4. Select Add dictionaries
  5. This will then take you to a page of Firefox add-ons called "Dictionaries & Language Packs"
  6. Scroll down to the dictionary called English (British). Install it.
  7. Restart Firefox, as prompted. You're done!

Mac users should edit in Safari

Global British spelling in Mac OS X is really solid and complete. The Firefox extension by Mark Tyndall (version 1.19.1) is not so good. It fails to take a stand on some of the most basic Trans-Atlantic spelling differences.

Moreover, the Firefox extension in no way offers auto suggestion, much less actual auto-correction. There is very little doubt that the Firefox British dictionary will produce more spelling errors than Safari.

Here's an idea of the difference between the two spell check environments:

Word Safari advice Firefox advice
color, humor, fervor, neighbor incorrect spelling incorrect spelling
materialize, colonize, fraternize, hypnoitize incorrect spelling Both -ize and -ise are seen as correct
organization incorrect spelling incorrect spelling (but organize is, confusingly, seen as a valid alternate spelling)
fulfill incorrect spelling incorrect spelling
install correct spelling (but instal is too — which is true, according to the OED) correct spelling (but instal is not, even though it should be)

For this reason, it is strongly recommended that Mac editors should use only Safari. Safari will simply correct more of your spelling errors than Firefox could possibly hope to do.

This recommendation does not extend to just Americans. Even British Mac users should use Safari, because Mark Tyndall's dictionary is the only known fix for British spell checking in Firefox. Regardless of where you live, Firefox by default only spell checks for American English, which forces you to go with the Tyndall add-on.

Nevertheless, we do still recommend you instal this British English Dictionary to Firefox, mainly on the principle that some correction is better than none.

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