Grammarly is a cloud-based writing assistant with a free tier and a paid Pro plan, working through a native Mac app, browser extensions and integrations with apps like Word, Outlook and Google Docs, though every keystroke it checks is sent to Grammarly's servers. LanguageTool, ProWritingAid and Antidote each apply the same cloud-checking model to a different niche, from an open, EU-based Grammarly rival to deep style analysis to bilingual French and English grammar, and Ginger remains a longstanding, if slower-moving, option in the same space. Apple's own Writing Tools, built into recent versions of macOS, proofread, rewrite and summarise text in most apps for free, without a subscription, though they check on request rather than as you type. The newest challengers are a cluster of on-device, system-wide Mac apps that arrived around 2026: Cotypist predicts and completes text system-wide on Apple Silicon Macs, Wysp offers free predictive text with an optional one-time Premium unlock, and Grambo applies on-device grammar checking for a small monthly fee or a one-time lifetime price. Charm sits in the same on-device category as this cluster, but corrects spelling and grammar rather than only predicting text.
| Rank | App | Best For | Price | Key Strength |
|---|---|---|---|---|
| 1 |  Charm |
System-wide grammar, spelling and prediction | $9.99 One-Time | Works in every Mac app, fully on-device |
| 2 |  iA Writer |
Focused long-form writing with style feedback | $49.99 One-Time | Style Check flags cliches and filler as you write |
| 3 |  Grammarly |
Cloud-based grammar and tone checking | Free / Pro subscription | Broad compatibility across a browser extension, Mac app and over a million web apps and programs |
| 4 |  Cotypist |
On-device system-wide text prediction | Free tier / subscription | Predicts and completes text system-wide on Apple Silicon Macs; prediction rather than grammar correction |
| 5 |  LanguageTool |
Open, EU-based grammar checking | Free / Premium from ~$4-20 monthly | Privacy-focused Grammarly rival, checked in the cloud rather than on-device |
| 6 |  ProWritingAid |
Deep style and readability analysis | ~$20/month or ~$399 lifetime | Aimed at long-form writers and editors who want more than grammar checking, checked in the cloud |
| 7 |  Grambo |
On-device grammar checking | $2.99/month or $14.99 lifetime | A newer, smaller on-device grammar assistant in the same emerging cluster as Charm |
| 8 |  Wysp |
Free on-device predictive text | Free, with one-time Premium | No subscription tier; focused on prediction rather than spelling or grammar correction |
| 9 |  Antidote |
Bilingual French and English grammar | ~€59/year | Popular with translators and editors who need both languages checked well |
| 10 |  Ginger |
Longstanding grammar and translation | Free / subscription | A familiar name in the category, though updated less often than newer rivals |
| 11 |  Apple Writing Tools |
Built-in proofreading and rewriting | Free (built-in) | Proofreads, rewrites and summarises text in most apps on request, but does not correct or predict as you type |
Charm
Spelling, grammar and word prediction.
Charm brings grammar checking and word prediction to every Mac app at once, correcting silently in place rather than flagging errors after the fact, and never sending a keystroke off the device.
- Corrects spelling silently in place as you type
- Fixes grammar in real time at natural pause points
- Predicts your next word in every app
- Processes everything on-device, with no account needed
iA Writer
Plain text writing at its most considered.
iA Writer is not a grammar checker in the traditional sense, but its Style Check catches cliches, filler and redundancy as you write, similar territory to Grammarly's tone suggestions, inside an editor built for long-form writing.
- Style Check flags cliches, filler and redundancy
- Focus Mode highlights only the sentence you are writing
- Authorship marks pasted and AI-generated text
- One-time purchase, and files stay as plain Markdown
Frequently asked
What is the best Grammarly alternative for Mac?
Charm is the closest system-wide alternative, correcting spelling and grammar and predicting your next word in every Mac app, all processed on-device. Cotypist, Wysp and Grambo form a newer on-device cluster chasing the same job, though each focuses more narrowly on prediction or a single check.
Does Grammarly still work well on Mac in 2026?
Yes, Grammarly's native Mac app and browser extensions cover Word, Outlook, Google Docs and most major web apps, though free-tier suggestions are limited to grammar, spelling and punctuation, with tone and clarity reserved for the paid Pro plan.
What is Cotypist, and how is it different from Charm?
Cotypist is an on-device Mac app that predicts and completes text system-wide on Apple Silicon Macs, similar in spirit to Charm's next-word prediction, though Charm also corrects spelling and grammar rather than only completing what you type.
Does Apple's Writing Tools replace a grammar checker like Charm?
Not entirely. Writing Tools proofread, rewrite and summarise text in most Mac apps for free, but only when you ask for it, whereas Charm corrects spelling and grammar continuously as you type and predicts your next word without a prompt.
Does Charm send my writing to a server?
No, Charm processes everything on the device, so nothing you type leaves the Mac and no account is required.
Is there a free option among these picks?
Not among the two ranked here, though Wysp's core predictive text is free with an optional one-time Premium unlock, and Apple's built-in Writing Tools cost nothing at all.