Firefox has its own in-built spell check, but this spell check is available only in text area and one thing you may have noticed is that Firefox only checks the spelling on large text fields. Many times blogging titles have spelling mistakes which built in spell checker miss out, but a simple trick can activate spell check in text fields as well. If you want Firefox to check the spelling in all text fields, you just have to tweak one of the settings.
To do this, open the config file of Firefox. Type about:config in address bar and press enter.
This will show up a warning to avoid making changes in the config file, just bypass this warning by clicking on I’ll be careful, I promise!
Now in the filter field, type the following value- layout.spellcheckDefault
The default value of this parameter is 1. Double click on this parameter and change the value to 2. Close config file and now open any page which has a textbox and check for wrong spelling.
You need to make sure Check my spelling as I type is checked in order for Firefox to do any spell checking. You can find this option in Tools > Options > Advanced tab.
Now get ready to gear up with the new level of spell checking right in your own Firefox browser, I hope you found this post useful.