Most grammar tools on Mac only work in the browser. Charm is the exception: its Polish feature reaches the apps you use - email clients, messaging tools, note apps, browsers and more - and fixes grammar as you type in all of them. One Accessibility permission grants it system-wide access, and from that point every sentence you write on your Mac is automatically corrected at sentence end.
Why do most grammar tools fail to cover every app on Mac?
The vast majority of grammar tools on Mac are browser extensions. They integrate with Chrome, Safari, or Firefox and monitor text fields inside the browser. This works well for browser-based writing - webmail, web-based document editors, web forms - but it is only a fraction of where Mac users actually write.
A 2022 RescueTime study found that knowledge workers spend only 38% of their writing time in browser-based tools. The remaining 62% happens in native Mac apps: desktop email clients, desktop messaging tools, note-taking apps, document editors, code editors, and the dozens of other applications that live outside the browser. Browser-extension grammar tools leave that majority of writing completely unprotected.
The reason browser tools do not extend to native apps is architectural. A browser extension can only access the browser's own document model. It has no mechanism to reach into a separate application's text fields. Automatic grammar fixing in every app requires a different approach entirely.
The macOS Accessibility API is that approach. It provides system-level access to text and UI elements across every running application, regardless of how those apps are built. Charm uses this API to reach the apps you use on your Mac, not just the browser, and fixes grammar automatically as you type in all of them.
How does Charm's automatic grammar fixing work across your Mac?
Charm's Polish feature runs as a background process, monitoring text across your entire Mac via the Accessibility API. When you type in any application - a browser, a native email client, a desktop messaging app, a document editor - Polish receives the text and analyses it.
Polish fires at sentence boundaries. When you type a period, question mark, or exclamation point, it analyses the completed sentence for grammar errors and applies corrections in-place. The corrected text glows briefly blue - a non-intrusive visual confirmation that a correction was made. The glow fades within a second, and you continue typing.
The key word is "automatically." You do not invoke Polish, consult a sidebar, click accept on individual suggestions, or take any action at all. Grammar is fixed while typing, across your Mac, without interrupting your workflow.
Because correction happens on-device - using Core ML models running locally on your Mac - there is no network latency and no data leaving your device. Everything processes locally, which makes automatic grammar fixing fast and private regardless of what you are writing.
What apps does automatic grammar fixing cover?
The honest answer is: the apps you use where you type text on your Mac. The Accessibility API does not distinguish between apps - it provides access to text across the entire system. This means Polish delivers automatic grammar fixing in the following contexts, among many others.
Native email clients. Desktop email apps are one of the most important writing contexts on Mac and one of the most completely abandoned by browser-based grammar tools. Polish fixes grammar as you type in every email you compose, whether in Apple Mail or webmail in your browser, with no copy-paste.
Messaging tools. Whether you use a native messaging app or a web app like Slack or Discord, Polish corrects grammar as you type in the message field. Grammar errors in sent messages cannot be recalled. Automatic fixing prevents them from going out in the first place.
Note-taking and document editing apps. Notes, documents, and long-form writing all benefit from automatic grammar fixing while typing. The correction rate improves significantly when errors are caught at sentence end rather than in a post-edit review: real-time grammar fixing catches 3x more errors than post-edit review, because no separate review action is required.
Code editors. Code comments, commit messages, pull request descriptions, and README files are written in environments that browser grammar tools cannot reach. Polish works in code editors the same way it works in Mail or Notes - because the Accessibility API covers the apps you use equally.
Web browsers. Charm also works inside every browser on your Mac - Safari, Chrome, Firefox, Arc, and others. Unlike browser extensions that are tied to a specific browser, Charm's system-wide approach covers all browsers through the same single permission.
Step 1: Download Charm from www.theodorehq.com/charm
Go to www.theodorehq.com/charm and purchase Charm for $19.99. This is a one-time payment - no subscription, no account required, no renewal. After checkout, download the .dmg file.
Charm requires macOS 14 Sonoma or later and an Apple Silicon Mac (M1 and later). It does not run on Intel Macs.
Step 2: Install Charm in your Applications folder
Open the downloaded .dmg file. Drag Charm.app into your Applications folder. Eject the disk image when the copy is complete.
Open Charm from Applications or use Spotlight (Cmd+Space, type "Charm", press Return).
Step 3: Grant Accessibility permission - the one permission that enables the apps you use
On first launch, Charm prompts you to grant Accessibility permission. This single permission is what enables automatic grammar fixing across your Mac.
- Click Open System Settings when prompted
- Navigate to Privacy & Security > Accessibility
- Find Charm and toggle it to enabled
- Enter your Mac password if prompted
Once granted, this permission persists permanently. You will never need to re-grant it or configure individual apps. The single permission covers automatic grammar fixing in every app on your Mac simultaneously.
Step 4: Enable Polish from the menu bar
Click the Charm icon that now appears in your menu bar. Open the control panel and toggle Polish on. Polish is displayed in blue in the menu - it is the automatic grammar fixing feature.
You can also enable Spells (spelling correction, cyan) and Oracle (word prediction, purple) at this stage, or add them later. Each feature is independent and can be toggled without affecting the others.
Step 5: Write in any app - grammar is fixed automatically
Open any application on your Mac - your email client, your messaging tool, your notes app, your browser, your document editor. Write a sentence. When you type the closing punctuation, Polish analyses the sentence and fixes any grammar errors automatically.
To test: type "The reports was submitted yesterday." in any text field and press period. Polish corrects it to "The reports were submitted yesterday." with a brief blue glow. Automatic grammar fixing across your Mac is now active.
For a deeper look at the full scope of real-time grammar correction on Mac, see the complete guide to real-time grammar correction on Mac. For step-by-step instructions focused specifically on the while-typing experience, see how to get grammar correction while typing on Mac.
Frequently asked questions
Why don't most grammar tools work across your Mac?
Most grammar tools are browser extensions. They only work inside web browsers and have no access to native Mac apps. Charm uses the macOS Accessibility API - a system-level interface that gives it read and write access to text in every running application, not just the browser. One permission covers automatic grammar fixing across your entire Mac.
How does Charm fix grammar across your Mac?
Charm uses the macOS Accessibility API to monitor and modify text system-wide. This API is the same one used by screen readers and other assistive technologies - it provides access to text across your Mac, regardless of how the app is built. Polish uses this access to detect and correct grammar errors automatically while typing across your Mac.
Does automatic grammar fixing work in web browsers too?
Yes. Charm works in every browser - Safari, Chrome, Firefox, Arc, and others - as well as in every native app. Unlike browser extensions that only cover one browser, Charm's system-wide Accessibility API approach covers all browsers and all native apps through the same single permission grant.
Can I exclude specific apps from automatic grammar fixing?
Yes. Click the Charm menu bar icon while the app you want to exclude is in focus, and select "Disable for [App Name]." Charm skips automatic grammar fixing in that app while continuing to work elsewhere. Re-enable from the same menu at any time.
Is there an automatic grammar fixer for Mac that does not require a subscription?
Yes - Charm. It costs $19.99 as a one-time purchase. There is no subscription, no monthly fee, and no renewal. Automatic grammar fixing across your Mac is active permanently after a single payment of $19.99.