How to Fix Spelling While You Type on Mac

macOS marks spelling errors with red squiggles but does not silently fix them - each one requires you to stop, right-click, and select a correction manually. To fix spelling while you type, without any manual action, you need Charm. Its Spells feature detects and replaces misspelled words automatically in under 200ms, in every app on your Mac, with a brief cyan glow as the only visible signal.

What does macOS actually do when it spots a spelling error?

The macOS spell checker takes a passive approach. When it detects a word that is not in its dictionary, it places a red dotted underline beneath it. That annotation stays there until you act on it. To fix the word, you right-click it, look at the suggested corrections in the context menu, select the correct form, and resume typing.

macOS does have a setting called "Correct spelling automatically" (found in System Settings under Keyboard - Text Input) but it only applies to a narrow set of very common patterns - primarily key transpositions like "teh" becoming "the". For the broad range of errors most writers make, it marks rather than corrects.

This is the red-squiggle model: annotate and wait. It works as a proofreading tool - useful for reviewing a finished document before sending. But it is a poor fit for writing-in-progress. Every interruption to fix a highlighted error is a break in composing flow. Research on writing productivity consistently shows that interruptions during drafting reduce both output quality and word count.

There is also a coverage gap. macOS spell check is part of the AppKit text framework and only operates inside apps that use Apple's native text rendering. Many modern Mac apps use non-native frameworks that bypass macOS text services entirely. In those apps, spell check is completely absent - no red squiggles, no corrections, nothing.

How is fixing spelling while typing different?

Fixing spelling while typing means errors are replaced as they occur, not annotated for later review. The correction is applied in the moment - within 200 milliseconds of the misspelled word being completed - and writing continues without pause. There is no right-click, no menu, no selection. The writer does not need to stop.

This is the same paradigm used on iOS and iPadOS, where autocorrect silently replaces common misspellings as you type on the on-screen keyboard. The experience feels natural and invisible precisely because it requires no action. macOS has never offered this experience natively for desktop use - it only shows squiggles and expects manual intervention.

The difference is significant at scale. The average writer makes 3 to 5 spelling errors per 100 words, according to Carnegie Mellon University research on typing behaviour. A professional writing 2,000 words per day accumulates 60 to 100 spelling errors that each require a separate manual correction action under the red-squiggle model. Under the silent auto-correction model, all 100 are fixed automatically, and zero manual actions are required.

How to fix spelling while typing on Mac: step-by-step setup

Charm is a native macOS app that provides silent auto-correction as you type. Here is how to set it up.

Step 1: Download and install Charm

Go to theodorehq.com/charm and click Get Charm. Complete the $9.99 one-time purchase - no subscription, no account required. Download the .dmg installer, open it, and drag Charm.app to your Applications folder. Eject the disk image when done.

Step 2: Open Charm and grant Accessibility permission

Launch Charm from your Applications folder. On first launch, macOS will prompt you to grant Accessibility permission. This permission is how Charm reads and corrects text across every app on your Mac. Click Open System Settings, enable Charm under Privacy and Security - Accessibility, and return to the app.

You only grant this permission once. Charm does not transmit your text anywhere - all correction happens on-device, locally on your Mac.

Step 3: Enable Spells from the menu bar

Click the Charm icon in your Mac's menu bar. You will see three toggles - Spells (spelling, cyan glow), Polish (grammar, blue glow), and Oracle (word prediction, purple glow). Toggle Spells on. The menu bar icon glows cyan to confirm it is active.

Step 4: Type in any app - spelling is fixed automatically

Open any application on your Mac and type. When you make a spelling error and complete the word with a space or punctuation mark, Charm replaces the misspelled word with the correct form. A brief cyan glow around the corrected word is the only signal - then writing continues. No right-click, no menu, no interruption.

Charm works in every app on your Mac - including apps where macOS spell check has no coverage. Whether you are writing in a native Apple app or in a messaging platform, productivity tool, or developer environment built on a non-native framework, Charm's correction is active.

What about words you do not want corrected?

Charm includes a personal dictionary where you can add words that should never be corrected. Technical terms, product names, surnames, and any other vocabulary specific to your work can be added to the dictionary so Charm leaves them untouched.

You can also disable Charm entirely for specific apps. If you are working in a code editor and prefer that Charm not touch variable names or code identifiers, click the menu bar icon while that app is frontmost and select Disable for [App Name]. Charm will stop correcting in that app while continuing to work everywhere else.

For more on managing Charm's dictionary and per-app settings, see the complete Charm setup guide.

Frequently asked questions

Does Mac fix spelling automatically while you type?

macOS can apply basic autocorrect for very common mistakes, but mostly it marks errors with red underlines and waits for you to fix them manually. It also only works in native apps. Charm provides true silent auto-correction - it replaces spelling errors automatically as you type, in every app, in under 200ms.

What is the difference between red squiggles and fixing spelling while typing?

Red squiggles annotate errors - they require you to stop, right-click, select a correction, and resume. Fixing spelling while typing means errors are replaced automatically the moment they are detected, with no action needed from you. Charm's Spells feature works this way - correction happens in under 200ms with a brief cyan glow.

How do I set up Charm to fix spelling while I type?

Download Charm from theodorehq.com/charm ($9.99 once). Open the app, grant Accessibility permission when prompted, then click the menu bar icon and toggle Spells on. From that point, spelling errors are corrected automatically as you type in every app on your Mac.

Will Charm correct technical terms or code variable names?

Charm is designed to avoid over-correcting unfamiliar words. You can add terms to a personal dictionary to ensure they are never changed. You can also disable Charm for specific apps where you want text left untouched - useful for code editors and terminal windows.

Does fixing spelling while typing slow down your Mac?

No. Charm is a lightweight native macOS app. Its correction processing takes under 200ms and runs on-device. It has no measurable impact on typing latency or system performance. Corrections are imperceptible during normal typing speed.