How to Check Grammar in Every App on Mac

The only way to check grammar in every Mac app - Mail, Slack, Notes, VS Code, Pages, and anything else you type in - is Charm's Polish feature. macOS has no built-in grammar checker, and Grammarly is a browser extension that stops at the browser tab. Polish uses the Accessibility API to deliver real-time grammar correction system-wide, across every application, with a single toggle.

Why checking grammar in every Mac app is harder than it sounds

Most Mac users assume their system is catching grammar errors the same way it catches typos. It is not. macOS has a spell checker built into most text fields - the red underline that appears when you type "teh" instead of "the." But spelling and grammar are different problems, and Apple's built-in tooling only addresses one of them.

The red underline will never appear under "She don't know the answer" because every word is spelled correctly. Grammar errors - subject-verb disagreement, incorrect tense, misused pronouns - pass straight through macOS's native checks without comment.

Apple Intelligence, introduced in macOS 15, does offer some grammar assistance, but only inside Apple's own apps (Mail, Notes, Pages, Safari) and only when you manually invoke it. It is not real-time, it is not available in third-party apps, and it requires macOS 15 Sequoia or later.

Studies show that knowledge workers send an average of 112 emails and Slack messages per day. The vast majority of that writing happens in native desktop apps, not browser tabs - which means browser-only tools like Grammarly cover only a fraction of where errors actually occur.

How Charm's Polish feature works system-wide

Charm is a native macOS app that sits in your menu bar. Its Polish feature uses the macOS Accessibility API - not NSSpellChecker - to monitor text input across every application simultaneously. When Polish detects a grammar error as you type, it corrects it automatically and silently. No popup, no red underline, no interruption.

Because it operates at the system level, Polish is app-agnostic. It works the same way in Safari as it does in Slack's desktop app, Apple Mail, VS Code, Obsidian, Bear, Terminal, or any other application that accepts text input. There is no per-app configuration required - enable it once and it covers everything.

All correction happens on-device. Your text never leaves your Mac. This makes Polish safe for drafting confidential emails, legal documents, medical notes, or any other sensitive material where cloud-based tools like Grammarly present a privacy risk.

How to set up system-wide grammar checking on Mac

Setup takes under two minutes. Follow these four steps:

Step 1: Download and install Charm

Go to theodorehq.com/charm and purchase Charm for $9.99. Download the .dmg file, open it, and drag Charm to your Applications folder. Launch Charm from Applications to continue.

Step 2: Grant Accessibility permission

When Charm launches for the first time, it will prompt you to grant Accessibility access. Click Open System Settings and enable Charm under Privacy and Security > Accessibility. This permission is what allows Polish to monitor and correct text across all applications. Without it, Charm cannot see text outside its own window.

Step 3: Enable Polish in the menu bar

Click the Charm icon in your Mac's menu bar. You will see toggle switches for each of Charm's three features: Spells (spelling), Polish (grammar), and Oracle (word prediction). Toggle Polish to on. Grammar checking is now active across every app on your Mac.

Step 4: Start typing in any app

Open any application - Mail, Slack, Notes, VS Code, Pages, or anything else - and start writing. Polish runs silently in the background and corrects grammar errors as you type. There is nothing else to configure.

What grammar errors does Polish actually catch?

Polish targets the grammar errors that appear most frequently in everyday writing. Here are some examples of the corrections it makes:

Polish corrects silently - the fix appears inline as you type, without any visual flag or notification. For users who are self-conscious about grammar difficulties, or who write on shared screens, this unobtrusive approach matters as much as the correction itself.

How this compares to other grammar checking options on Mac

There are four realistic options for grammar checking on Mac. Here is how they compare:

Charm is the only option that combines system-wide coverage, real-time correction, on-device privacy, and a one-time price. For a deeper look at the Grammarly comparison specifically, see Charm vs Grammarly.

Frequently asked questions

Does macOS have a built-in grammar checker?

macOS includes a spell checker built into most apps, but it only catches misspelled words - not grammar errors. It will not flag subject-verb disagreement, incorrect tense, or missing articles. For actual grammar correction across every Mac app, you need a dedicated tool like Charm.

Does Grammarly work in every Mac app?

No. Grammarly on Mac is a browser extension only. It works inside Chrome, Safari, and Firefox, but does nothing in Mail, Slack desktop, Notes, VS Code, Pages, or any other native Mac application. Charm's Polish feature is the only grammar checker that covers every Mac app.

Does Charm send my text to the cloud to check grammar?

No. Charm's Polish feature runs entirely on your Mac using on-device processing. Your text never leaves your device. This makes it safe to use when drafting confidential emails, legal documents, or any other sensitive material.

Can I disable grammar checking in specific apps like VS Code?

Yes. Click the Charm menu bar icon and you can disable Polish for any specific application. This is useful for code editors where sentence-level grammar analysis is not helpful. All other apps continue to receive grammar correction as normal.

What macOS version does Charm require?

Charm requires macOS 14 Sonoma or later. It is a native macOS app that uses the Accessibility API to monitor and correct text across all applications on your Mac.