Spellcheck Tweak

Allows the spell checker to check both single and multi-line text area fields.

Compatibility

Works with: Firefox 3.6+

Background

By default Firefox will not check single line text area fields.

The Tweak

This flaw can be fixed with a simple about:config modification.

1. Open a new tab and type about:config in the address bar and press enter
2. In the filter field type layout.spellcheckDefault
3. Double-click on the entry and in the pop-box enter 2
4. Click OK

Notes

Original Article

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Updated: November 15, 2025