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

Spell check runs automatically in Microsoft Word as you type. Red squiggly lines under words mean Word doesn't recognize them in its dictionary. If you don't see these lines, spell check is either turned off or set to check only when you finish editing. You can turn it back on in a few clicks, and the process is the same whether you use Word on Windows, Mac, or the web version.

The setting lives in Word's options menu, not in the ribbon toolbar. Once you know where to look, you can toggle spell check on or off whenever you need to — some people turn it off temporarily while drafting, then turn it back on before they finish.

Key Takeaways

  • Spell check is on by default in Word and shows red squiggly lines under words it doesn't recognize.
  • On Windows, go to File > Options > Proofing and check the box next to "Check spelling as you type."
  • On Mac, go to Word > Preferences > Spelling and Grammar and select "Check spelling as you type."
  • In Word Online, go to File > Options > Proofing and turn on "Check spelling as you type."
  • You can right-click any red-underlined word to see suggested corrections or add it to your dictionary.

Turn spell check on in Word for Windows

Open Word and go to the File menu in the top left. Click Options at the bottom of the menu. A window titled "Word Options" will open.

In the left sidebar, click Proofing. Look for the section labeled "Spelling" and find the checkbox next to "Check spelling as you type." If the box is empty, click it to turn spell check on. If it already has a checkmark, spell check is already running — the red lines may just be hidden because you're in a different view mode.

Click OK at the bottom of the window to save your change. You should see red squiggly lines appear under misspelled words the next time you type or open a document.

Turn spell check on 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 Preferences window, find and click Spelling and Grammar. Look for the checkbox next to "Check spelling as you type" and make sure it has a checkmark. If it doesn't, click the box to enable it.

Close the Preferences window. Spell check will start working when ready on any new text you type or any document you open.

Turn spell check on in Word Online

Open your document in Word Online (the version you access through Office.com or OneDrive). Click File in the top left corner, then select Options from the menu.

Click Proofing in the left sidebar. Find the checkbox for "Check spelling as you type" and click it if it's unchecked. The setting takes effect right away — you don't need to click a save button.

What to do when spell check finds a word

When spell check underlines a word in red, you have several options. Right-click the word to see a menu of suggested corrections. Click any suggestion to replace the word when ready.

If the word is correct but Word doesn't recognize it — like a proper name or technical term — you can click "Add to Dictionary" from the same menu. Word will stop flagging that word in any document you write going forward. You can also click "Ignore All" to skip that word for the rest of your current document only.

Why spell check might not be showing red lines

Even with spell check turned on, you won't see red lines in certain situations. If you're in Read Mode or Outline View, spell check still runs but doesn't display the underlines. Switch to Print Layout or Draft view to see them. Click View in the ribbon and choose your preferred view.

Another reason is that Word may be set to check spelling only when you finish editing. This is less common but possible if someone changed your settings. Go back to Proofing options and look for a checkbox labeled "Hide spelling errors" or "Hide grammar errors." If either is checked, uncheck it.

Customize what spell check catches

In the Proofing options menu, you can fine-tune spell check behavior. You can tell Word to ignore words in ALL CAPS, ignore words with numbers, or ignore internet addresses. You can also choose whether to check spelling in a different language if you write in multiple languages.

Some people turn off "Check spelling as you type" but leave "Check grammar as you type" on, or vice versa. This lets you focus on one type of error at a time. You can always run a full spell and grammar check manually by pressing F7 on Windows or Fn + F7 on Mac, which scans your entire document at once.

Frequently Asked Questions

Can I turn spell check on for just one document?

No — the setting applies to all documents you open in Word. However, you can ignore specific words in a single document by right-clicking them and selecting "Ignore All," which only affects that document. To turn spell check back on for other documents, you have to change it in Options again.

What if I want spell check to ignore certain words permanently?

Right-click the word and click "Add to Dictionary." Word will stop flagging it in any document. If you change your mind later, you can remove it from the dictionary by going to File > Options > Proofing > Custom Dictionaries, selecting the dictionary, and clicking "Edit Word List."

Does spell check work the same way in Word and Google Docs?

No. Google Docs has spell check built in and always running, with no options menu to turn it off. Word gives you more control — you can disable it, customize what it ignores, and choose between checking as you type or checking only when you run a manual scan.

Why does spell check underline words I know are spelled correctly?

Word's dictionary doesn't include every word, especially proper nouns, technical terms, and newer slang. Right-click the word and click "Add to Dictionary" so Word stops flagging it. You can also click "Ignore All" if you only want to skip it in that one document.

Can I check spelling without seeing red lines as I type?

Yes. Turn off "Check spelling as you type" in Proofing options, then press F7 (or Fn + F7 on Mac) whenever you want to run a full spell check. A panel will open showing all errors at once, and you can fix them one by one or skip them.