Spell check is already installed in Word — you just need to turn it on

Microsoft Word comes with spell check built in. You do not need to read or install anything. The feature is there by default, but it may be turned off, or you may need to adjust where and how it works. This guide walks you through finding the spell check settings, turning it on if it is off, and choosing what Word checks as you type.

The steps differ slightly between Word on Windows, Word on Mac, and Word Online, so find your version below and follow those instructions.

Key Takeaways

  • Spell check is built into Word and does not require installation — you only need to turn it on in settings.
  • In Word on Windows and Mac, spell check runs automatically as you type and marks errors with a red underline.
  • Word Online has spell check turned on by default, but you can turn it off in the Editor pane if you prefer.
  • If spell check is not working, check that it is enabled in File > Options (Windows) or Word > Preferences (Mac).
  • You can add words to your personal dictionary so Word stops marking them as errors.

Turn on spell check in Word on Windows

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

On the left side of the Word Options window, click Proofing. You will see a section called "Spelling" with checkboxes next to different options. Make sure the box next to Check spelling as you type is checked. If it is not, click it to turn spell check on.

Below that, you may see other options like "Hide spelling errors" or "Hide grammar errors". Leave these unchecked so Word shows you the errors. When you are done, click OK at the bottom right. Spell check is now on and will mark misspelled words with a red underline as you type.

Turn on spell check in Word on Mac

Open Word and click Word in the menu bar at the very top of your screen. Click Preferences. A window will open with several icons. Look for and click the icon labeled Spelling.

In the Spelling window, check the box next to Check spelling as you type. You should also see a checkbox for Use smart spelling — this is optional but helpful, as it catches some errors the basic spell check misses. Click the red close button when you are done. Spell check is now on.

Spell check in Word Online

Word Online (the version you use in a web browser) has spell check turned on by default. As you type, misspelled words will be underlined in red. You do not need to change any settings unless you want to turn it off.

If you want to see more detailed feedback about spelling and grammar, click the Editor button on the right side of the ribbon (the toolbar at the top). The Editor pane will open and show you a list of any spelling or grammar issues in your document. You can click each one to see what Word suggests.

What to do when Word marks a word as wrong but it is correct

Word sometimes marks proper nouns, technical terms, or less common words as misspelled even though they are correct. When this happens, right-click the underlined word. A menu will appear with options including Add to Dictionary. Click this option and Word will stop marking that word as an error in any document you write going forward.

If you only want Word to ignore the word in this one document, click Ignore All instead. The word will no longer be marked as wrong in this document, but Word will still flag it in other documents.

Check spelling in a document you have already written

If you have a document with many words and want to check all of them at once, use the full spell check tool. On Windows, press Ctrl + A to select all text, then go to Review in the ribbon and click Spelling & Grammar. On Mac, press Command + A to select all, then click Review and Spelling and Grammar.

A window will open showing each potential error one at a time. For each word, you can choose to Ignore it, Ignore All instances of it, Change it to a suggestion, or Add it to your dictionary. Work through each error and click OK when you reach the end.

Adjust what spell check looks for

By default, Word checks spelling but may not check grammar, or may check it lightly. If you want Word to also catch grammar mistakes, go back to the Proofing settings (File > Options > Proofing on Windows, or Word > Preferences > Spelling on Mac) and look for an option called Grammar or Check grammar as you type. Check that box to turn grammar checking on.

You can also choose how strict the grammar check is. Some versions of Word let you select a style like "Grammar Only" or "Grammar and More" to control how many potential issues Word flags. Choose the level that works for your writing.

Frequently Asked Questions

Why is spell check not working even though I turned it on?

Make sure you clicked OK or explore to save your changes in the Options or Preferences window. If you did and spell check still is not working, close Word completely and open it again. Sometimes the settings do not take effect until you restart the program.

Can I turn off spell check if I do not want the red underlines?

Yes. Go back to File > Options > Proofing (Windows) or Word > Preferences > Spelling (Mac) and uncheck the box next to "Check spelling as you type". The red underlines will disappear, though you can still run a full spell check manually whenever you want.

Does spell check work the same way in all languages?

Word can check spelling in many languages, but you need to tell it which language your document is in. Highlight the text, go to Review > Language > Set Proofing Language, and choose your language. Word will then check spelling against that language's dictionary.

What if I share my document with someone else — will they see my personal dictionary?

No. Your personal dictionary (the words you added) stays on your computer. When someone else opens your document, Word will use their own dictionary. Words you added will not be marked as correct for them unless they add those words to their dictionary too.