How to Switch On Spell Check in Microsoft Word

Spell check is one of Word's most useful background features — quietly catching typos, repeated words, and basic grammar errors as you type. But it doesn't always behave the way you expect. Sometimes it stops working after an update. Sometimes it was never turned on in the first place. And in some setups, it appears active but silently ignores entire documents.

Here's what's actually happening under the hood, and what controls whether spell check works for you.

What Spell Check in Word Actually Does

Microsoft Word uses two spell-checking mechanisms that often get confused:

• Check spelling as you type — the real-time red underline that flags words as you write
• Manual spell check — triggered by pressing F7 or going to Review > Spelling & Grammar, which scans the full document on demand

Both rely on the same dictionary engine, but they're controlled by separate settings. Turning one on doesn't automatically activate the other.

There's also a third layer: AutoCorrect, which silently fixes common errors before you even see them. This is separate from spell check entirely, though many users assume it's the same thing.

How to Turn On Spell Check in Word (Windows)

Enable "Check Spelling as You Type"

1. Open Word and go to File > Options
2. Select Proofing from the left-hand menu
3. Under When correcting spelling and grammar in Word, check the box for Check spelling as you type
4. Also check Mark grammar errors as you type if you want grammar flagging alongside spelling
5. Click OK

Red underlines should now appear under unrecognised words as you type. 🔴

Run a Manual Spell Check

Press F7 at any time, or navigate to Review > Spelling & Grammar in the ribbon. Word will scan the document from your cursor position and surface errors one by one.

How to Turn On Spell Check in Word (Mac)

The path is slightly different on macOS:

1. Open Word and go to Word > Preferences (top menu bar)
2. Click Spelling & Grammar
3. Check Check spelling as you type and Check grammar as you type
4. Close the preferences panel

The keyboard shortcut for a manual check on Mac is also F7, though on some Mac keyboards you'll need to press Fn + F7.

Why Spell Check Might Still Not Be Working

Turning on the setting is often only half the problem. Several other factors can silently disable spell checking even when the option appears active.

The Document Language Is Set Incorrectly

Word checks spelling against a specific language dictionary. If your document — or a section of it — is tagged with the wrong language, Word either uses the wrong dictionary or skips checking altogether.

To fix this:

• Select all text (Ctrl+A or Cmd+A)
• Go to Review > Language > Set Proofing Language
• Choose the correct language
• Make sure Do not check spelling or grammar is unchecked

This is one of the most common reasons spell check silently fails, especially in documents that were copied from another source or created on a different machine.

"Do Not Check Spelling or Grammar" Is Enabled

Word allows this setting to be applied at the document level or even to individual text selections. If a previous user (or a template) enabled it, spell check will appear to run but flag nothing.

Follow the same steps as above — selecting all text first — and confirm that checkbox is cleared.

The Custom Dictionary Is Interfering

If words you've previously added to your custom dictionary are wrong, Word will never flag them. Go to File > Options > Proofing > Custom Dictionaries to review and edit your personal word list.

Proofing Tools Aren't Installed

In some versions of Office — particularly volume-licensed or stripped-down installations — the language proofing tools for your region may not be installed. This is more common in enterprise environments where IT controls the Office installation. In these cases, the spell check setting exists but has no dictionary to reference.

You can check by going to File > Options > Language and seeing whether your preferred language shows Proofing installed or not.

Spell Check Behaviour Across Word Versions

Word Online is worth flagging separately: the browser version has a noticeably reduced proofing experience compared to the desktop app. If you're working in Word Online and spell check feels incomplete, that's expected — it's a platform limitation, not a settings problem. ✅

The Variables That Change How This Plays Out

Whether spell check works reliably — and how well — depends on several factors that vary from one setup to another:

• Which version of Word you're running (Microsoft 365 subscription vs. a one-time purchase vs. the online app)
• Your operating system and its language settings, which Word partially inherits
• How your document was originally created — templates, imported text, and copy-pasted content can all carry hidden proofing settings
• Whether your Office installation includes proofing tools for your language, which is an IT/admin decision in managed environments
• Your keyboard and device language settings on mobile, where Word offloads some spell checking to the operating system

Someone using Microsoft 365 on a personal Windows laptop with English (UK) installed will have a very different experience from someone using a workplace-managed Office 2019 installation in a multilingual environment — even if both have "spell check" technically turned on.

The setting itself is simple. What determines whether it actually works end-to-end is the combination of your Office version, installation type, document history, and language configuration — and those vary enough that the right fix isn't always the same one. 🔍