Spell check is on by default in Word, but you may need to turn it back on if it was disabled

Microsoft Word runs spell check automatically as you type — red squiggly lines appear under words it doesn't recognize. If you're not seeing those lines, spell check is likely turned off. The steps to turn it back on depend on whether you use Word on Windows, Mac, or the web version.

Spell check in Word catches misspelled words and some grammar issues. It won't catch every error — it can't tell if you meant to write "their" instead of "there" — but it catches typos and words that aren't in its dictionary. You can also add words to your personal dictionary so Word stops flagging them.

Key Takeaways

  • Word displays red squiggly lines under misspelled words when spell check is on, and this feature is enabled by default.
  • On Windows, go to File > Options > Proofing and check the box next to "Check spelling as you type" to turn spell check back on.
  • On Mac, open Word > Preferences > Spelling and Grammar and select "Check spelling as you type" from the dropdown menu.
  • You can right-click any flagged word to see suggestions, ignore it once, or add it to your dictionary so Word stops flagging it in the future.

Turn on spell check in Word for Windows

Open Word and go to the File menu in the top left. Click Options at the bottom of the menu. In the window that opens, click Proofing on the left side.

Look for the section labeled "When correcting spelling and grammar in Word." Find the checkbox next to "Check spelling as you type" and click it to put a checkmark there. If it already has a checkmark, spell check is already on. Click OK at the bottom right to save and close the window.

Red squiggly lines should now appear under misspelled words as you type. If they don't show up right away, try typing a word you know is misspelled to test it — for example, "teh" instead of "the."

Turn on spell check in Word for Mac

Open Word and click Word in the menu bar at the very top of your screen. Select Preferences from the dropdown menu. In the window that opens, look for Spelling and Grammar and click it.

You'll see a dropdown menu next to "Check spelling." Click it and select "Check spelling as you type" from the options. Close the preferences window. Red squiggly lines should now appear under misspelled words as you type.

Turn on spell check in Word Online

If you use Word through a web browser (Word Online), spell check is usually on by default. To check, click Review in the ribbon at the top. Look for a button labeled Spelling or Editor. If you see it, spell check is active.

If you don't see the Spelling button, click the three dots (more options) on the right side of the Review tab. Look for Spelling in that menu and click it to turn it on. The web version of Word doesn't always show squiggly lines the same way the desktop version does, but it will flag errors when you run the spell check tool.

What to do when Word flags a word

When you see a red squiggly line under a word, right-click it to see options. Word will show you spelling suggestions at the top of the menu. Click any suggestion to replace the misspelled word with that option.

If the word is spelled correctly but Word doesn't recognize it — like a proper name or technical term — you have two choices. Click Ignore to skip it this time, or click Add to Dictionary to tell Word to stop flagging it in any document you write. Adding to your dictionary is useful for names, brand names, or specialized words you use often.

Turn off spell check if you don't want it

Some people find the red squiggly lines distracting while drafting. You can turn spell check off and turn it back on later. Follow the same steps as above — go to File > Options > Proofing on Windows, or Word > Preferences > Spelling and Grammar on Mac — and uncheck the box next to "Check spelling as you type."

Even with spell check off, you can still run a manual spell check at any time. On Windows, press F7 or go to Review > Spelling & Grammar. On Mac, go to Review > Spelling and Grammar. This opens a window that checks your entire document at once.

Spell check vs. grammar check

Spell check and grammar check are different tools. Spell check catches misspelled words. Grammar check catches issues like subject-verb disagreement, missing punctuation, and awkward phrasing. In Word, you can turn these on and off separately in the same Proofing or Spelling and Grammar menu.

Grammar check appears as a blue squiggly line under text. If you see both red and blue lines in your document, both tools are on. You can turn off grammar check if you only want spelling feedback, or turn off spell check if you only want grammar feedback.

Frequently Asked Questions

Why isn't spell check working even though I turned it on?

Make sure you're looking at the right setting. In Windows, the option is called "Check spelling as you type" under File > Options > Proofing. On Mac, it's in Word > Preferences > Spelling and Grammar. Also check that you didn't accidentally turn on "Hide spelling errors" — this hides the red lines but doesn't turn off spell check itself.

Can I add multiple words to my dictionary at once?

No, Word requires you to add words one at a time by right-clicking and selecting "Add to Dictionary." There's no bulk import feature in the standard version. If you add a word by mistake, you can remove it by going to File > Options > Proofing > Custom Dictionaries on Windows, or Word > Preferences > Spelling and Grammar > Dictionaries on Mac.

Does spell check work in all languages?

Word includes dictionaries for many languages, but you need to tell it which language your document is in. Select the text, go to Review > Language, and choose the correct language. Spell check will then use that language's dictionary. If you write in multiple languages in one document, you may need to set the language for each section separately.

What's the difference between ignoring a word and adding it to my dictionary?

Ignoring a word skips it only in that moment — the next time you write the same word, Word will flag it again. Adding it to your dictionary tells Word to never flag that word in any document you write from now on. Use "Ignore" for one-time words and "Add to Dictionary" for words you use regularly.