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

Microsoft Word checks your spelling as you type and marks errors with a red squiggly underline. This feature comes enabled automatically when you install Word, so you likely already have it running. If you don't see red underlines under misspelled words, spell check has been turned off — either accidentally or because a previous setting change disabled it. Turning it back on takes less than a minute.

The steps differ slightly depending on whether you're using Word on Windows, Mac, or the web version. All three versions store the spell-check setting in the same general location: the Options or Preferences menu. The setting applies to the current document and all future documents you create, so you only need to change it once.

Key Takeaways

  • Spell check is enabled by default in Word and marks misspelled words with a red underline as you type.
  • 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 check "Check spelling as you type."
  • On Word Online, go to File > Options > Proofing and enable the spelling option in the same way as Windows.
  • If spell check is off for a single document, you can turn it on just for that file without affecting others.

Turning on spell check in Word for Windows

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

In the left sidebar, click Proofing. You'll see a section called "Spelling" with several checkboxes. Look for the box labeled "Check spelling as you type" and click it to add a checkmark. If the box already has a checkmark, spell check is already on. Click OK at the bottom right to save the change and close the window.

Word will now underline misspelled words in red as you type. Right-click any red-underlined word to see suggested corrections or add it to your dictionary if it's a word Word doesn't recognize.

Turning on spell check in Word for Mac

Open Word on your Mac. In the menu bar at the top of the screen, click Word, then select Preferences from the dropdown menu. A new window will open.

Look for Spelling and Grammar in the list and click it. You'll see a checkbox next to "Check spelling as you type." Click the checkbox to enable it. If it's already checked, spell check is on. Close the Preferences window when you're done.

Turning on spell check in Word Online

If you use Word through Microsoft 365 in your web browser, the process is similar to Windows. Click File in the top left, then select Options. Click Proofing in the left sidebar.

Under the "Spelling" section, make sure "Check spelling as you type" is enabled. The setting will save automatically when you close the Options panel. Spell check will then mark errors with a red underline in your document.

What to do if spell check is off for only one document

Sometimes spell check is disabled for a single document instead of your entire Word installation. This can happen if the document was created with spell check off or if someone shared it with that setting already disabled.

To turn spell check on for just that document, go to File > Options > Proofing (Windows) or Word > Preferences > Spelling and Grammar (Mac) and enable "Check spelling as you type." This will turn it on for that document and all future documents. If you want spell check on for this document but off for others, you'll need to toggle the setting each time you switch documents.

Understanding the red underline and how to use it

When spell check is on, Word underlines words it doesn't recognize in red. This doesn't always mean the word is misspelled — it might be a proper noun, a technical term, or a word not in Word's dictionary. Right-click the underlined word to see options.

You'll see a list of suggested corrections at the top of the menu. Click a suggestion to replace the word. If the word is spelled correctly, click "Add to Dictionary" to tell Word to stop marking it as an error in the future. You can also click "Ignore All" to stop marking that particular word as an error in the current document only.

Why spell check might not be working even after you turn it on

If you've enabled spell check but still don't see red underlines, check whether the document language is set correctly. Word checks spelling based on the language you've selected. If the language is set to something you don't use, spell check may not recognize your words as errors.

To change the language, select all text in the document using Ctrl+A (Windows) or Command+A (Mac). Then go to Review > Language (Windows) or Tools > Language (Mac) and choose the correct language. Word will then check spelling against that language's dictionary.

Another reason spell check might seem off is if you're using a template or document style that has spell check disabled. In this case, enabling it through Options (as described above) will override the document's settings.

Frequently Asked Questions

Can I turn off spell check for certain words or phrases?

Yes. Right-click a red-underlined word and select "Ignore All" to stop Word from marking that word as an error in the current document. If you want to ignore it in all documents, add it to your dictionary by clicking "Add to Dictionary" instead.

Does spell check work the same way in Word Online as it does in the desktop version?

Spell check works similarly in both versions, but Word Online has fewer customization options. The basic "Check spelling as you type" setting is available in both, but some advanced proofing features are only in the desktop version.

What's the difference between spell check and grammar check?

Spell check catches misspelled words. Grammar check catches sentence structure, punctuation, and word choice errors. Both are separate settings in Word's Proofing options, and you can turn either one on or off independently.

If I add a word to my dictionary, will it appear in spell check on other computers?

No. Your personal dictionary is stored on your computer. If you use Word on multiple devices, you'll need to add words to the dictionary on each device separately. Words added on one computer won't transfer to another.

Why does Word underline my name or company name in red?

Word's dictionary doesn't include most proper nouns. Right-click the underlined name and select "Add to Dictionary" so Word stops marking it as an error. After you add it, Word will recognize it in all your documents.