Firefox automatically checks the spelling of words that you enter in text boxes. As soon as you finish typing a word, it is checked against the words in the installed dictionary. If the word is not found in the dictionary, it will be underlined in red, as in the following example:

Disable automatic spell-checking

By default, Firefox is configured to automatically check spelling. You can turn it off in the Settings window:

1. In the Menu bar at the top of the screen, click Firefox and then select Preferences or Settings, depending on your macOS version.Click the menu button and select Settings.
2. In the General panel, go to the Language section.
3. Uncheck Check your spelling as you type.

   

4. Close the Settings page. Any changes you've made will automatically be saved.

Correct misspelled words

When spell-checking is enabled, you can easily correct misspelled words. To correct the misspelled word, Right-clickHold down the Control key while you click on it and select one of the suggested words at the top of the menu.

If none of the suggested words is appropriate, you must manually edit it. If you are sure the word is spelled correctly, you can add it to the dictionary. To add a word to the dictionary, Right-clickHold down the Control key while you click on it, and select Add to Dictionary.

Add dictionaries

You can install other dictionaries as necessary.

1. Right-clickHold down the Control key while you click in any text box containing more than one line.
2. Select Languages.
3. Select Add dictionaries.

   

4. The Dictionaries & Language Packs page is displayed. Find a language on the list and click on it to open its page.
5. Click the Add to Firefox button on the page that opens. When the warning panel appears, clickAdd to allow the installation.

   

Switch dictionaries

After the dictionary is installed, you can switch to it, as needed. To switch to a different installed dictionary, Right-clickHold down the Control key while you click in a multi-line field, select Languages, then select the dictionary you want to use.

You can select more than one dictionary. The spell checker will also check spelling against multiple languages.

Remove a word you have accidentally added

1. Open your profile folder:

   • Click the menu button , click Help and select More Troubleshooting Information.From the Help menu, select More Troubleshooting Information. The Troubleshooting Information tab will open.
   • Under the Application Basics section next to Profile FolderProfile Directory, click Open FolderShow in FinderOpen Directory. A window will open that contains your profile folder.Your profile folder will open.Your profile directory will open.
   Note: If Firefox displays an error after clicking Open Folder or if you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.

2. Click the Firefox menu and select Exit.Click the Firefox menu at the top of the screen and select Quit Firefox.Click the Firefox menu and select Quit.
3. Open the file persdict.dat in a text editor (such as WordPad) (such as Pages) (such as Calligra Words).
4. In the text editor, each word you've added is on a separate line. Remove the line, containing the word you wish to remove.
5. Click the File menu, and select Save, to save your work.