Cotypist vs Grammarly AI

They help at different moments. Cotypist is autocomplete for your Mac: it predicts the next few words in any app and you press Tab to take them, with the model running on the machine. Grammarly checks and rewrites what you've already written (grammar, tone, clarity) and works on Windows, Mac, browsers and phones. Some people run both.

If you're not on an Apple Silicon Mac

Then it's Grammarly. Cotypist only runs on Apple Silicon Macs, with no Windows or Linux version yet. Grammarly lists desktop apps for Windows and Mac, extensions for Chrome, Safari, Firefox and Edge, add-ins for Microsoft Office and Google Docs, and iPhone, iPad and Android apps. The Grammarly site footer now reads Superhuman Platform, and Enterprise is sold through Superhuman Go.

Privacy and what runs where

Cotypist's FAQ says suggestions are generated entirely on the Mac, work offline, and nothing is processed or logged in the cloud. That's the main reason to choose it for confidential writing. It also lets you set writing instructions, and on Pro, separate instructions per app, so Slack replies and client emails can sound different.

Grammarly's strength is the second pass: catching mistakes, adjusting tone, rewriting whole sentences, and on Pro, plagiarism and AI-text detection. It's the better tool when the problem is correctness rather than typing speed.

Price for one person

Cotypist Free gives 100 accepted words a day. Plus is $6 a month ($72 a year) for unlimited completions on one Mac; Pro is $9 a month ($108 a year) for up to three of your own Macs, all models and per-app instructions. Every new install gets 30 days of Pro with no card.

Grammarly Free includes 100 AI prompts a month on top of basic grammar and spelling. Pro is shown at $12 a month with a free trial and 2,000 AI prompts per member. Enterprise is custom-priced with unlimited prompts.