Test spelling in a field that accepts several lines, such as an unsent message body. If a deliberate typo stays unmarked, search Firefox Settings for Check your spelling as you type, turn it on and confirm that a dictionary is installed.
01Try a field with room for several lines
Section linkType a made-up word in a message body or comment box and finish it with a space. Firefox enables automatic checking by default in multi-line fields. If you see an underline there but see none in a short search box, use the multi-line field to test the browser setting.
02Turn checking on and pick a dictionary
Section linkIn the multi-line field, right-click or Control-click on a Mac. If Check Spelling appears and is unchecked, turn it on. Under Languages, choose the dictionary for the text you are writing. If Firefox underlines many ordinary words, test with just the dictionary for that language selected.
03Install a spelling dictionary if it is missing
Section linkIf you see Add Dictionaries under Languages, use it. If the menu is missing, open Mozilla’s Dictionaries and Language Packs directory from the sources below. Choose an entry in the dictionary column for your language or region, open its page and select Add to Firefox. Then return to the field and select the dictionary. A language pack changes Firefox’s interface language.
04Compare with a field on another site
Section linkRepeat the same typo test in another site’s multi-line field. If Firefox marks it there, focus on the original page or its editor settings. If no field marks it, check that the intended dictionary is selected and the browser-wide spelling setting is enabled.