Browser spell check is easy to take for granted until the red underlines disappear. Usually the feature has been switched off, the wrong language is selected, or a writing extension is interfering with the built-in checker.
Does this affect you?
Use this when misspelled words are no longer marked while typing into browser forms, emails, social posts, comment boxes, or web editors in Chrome, Firefox, or Safari on Windows or Mac. Browser spell check works only inside editable fields, not on regular page text.
Turn spell check back on in Chrome
Chrome has both the main spell check switch and language-specific controls.
- Click the three-dot menu and open Settings.
- Choose Languages in the sidebar.
- Open Spell check.
- Turn on the main Spell check setting.
- Make sure the language you type in is selected. Add the language if it is missing.
- Return to a text box and type a misspelled word to test the underline.
Enhanced spell check may also appear in Chrome. Use it only if you are comfortable with Chrome sending text to Google for stronger checking.
Turn spell check back on in Firefox
Firefox uses one internal preference, plus a right-click option that can affect individual fields.
- Type about:config in the address bar and press Enter.
- Accept the warning if Firefox shows one.
- Search for layout.spellcheckDefault.
- Set the value to 1 for multi-line text boxes, or 2 if you want Firefox to check single-line fields too. If it is 0, spell check is off.
- If the problem affects only one field, right-click inside that field and make sure Check Spelling is enabled.
- Reload the page and test again.
Turn spell check back on in Safari
Safari keeps spelling controls in the macOS menu bar rather than only inside Safari settings.
- Open Safari and click into a text box if possible.
- Click Edit in the Mac menu bar.
- Open Spelling and Grammar.
- Enable Check Spelling While Typing.
- Enable Correct Spelling Automatically too if you want Safari to fix common mistakes as you type.
- Type a misspelled word in a web form to confirm Safari is checking again.
More control
Check the language
If spell check works in one language but misses obvious mistakes in another, the wrong dictionary is probably active. In Chrome, revisit Languages > Spell check. On Mac, check System Settings > Keyboard > Text Input and review enabled dictionaries.
Test writing-assistant extensions
Extensions such as grammar checkers can replace or conflict with built-in browser spell check. Disable them temporarily from the browser extension manager, then test the same text box again.
Recheck after browser updates
A browser update can reset language selections or spell check behavior. The main switch may still be on while the language you need has been removed from the active list.
Understand the limit
Browser spell check checks text you type into editable areas. It does not scan regular article text, labels, or already published page content because those parts of the page are not editable.
Sources
- Google Chrome Help – Check spelling in Chrome (2025)
- Mozilla Support – Spell check your text (2025)
- Apple Support – Check spelling and grammar on Mac (2025)