Charm and Cotypist are both private, on-device writing tools for Mac, and both predict your next words as you type. The core difference is scope and price. Cotypist is a focused autocomplete tool sold as a subscription. Charm does word prediction too, but adds real-time spelling and grammar correction, runs on Intel Macs as well as Apple Silicon, and costs $9.99 once. If you want only the best possible autocomplete, Cotypist is excellent. If you want prediction plus correction in a single one-time purchase, Charm covers more ground.
What does each tool actually do?
Cotypist is an autocomplete engine. As you type in almost any Mac text field, it shows a grey "ghost text" prediction of the rest of your sentence. Press Tab to accept the next word or the whole line, and keep typing if you would rather not. It learns your vocabulary and phrasing over time, so the suggestions start to sound like you. It is a genuinely good, well-made tool, and prediction is its entire focus.
What Cotypist does not do is correct your writing. It includes light typo handling, but there is no sentence-level grammar correction. If you misspell a word it has not learned, or write a grammatically awkward sentence, Cotypist will not fix it - that is simply not what it is built for.
Charm does three jobs in one app. Oracle is Charm's word-prediction feature, directly comparable to Cotypist's autocomplete: it suggests your next word and you accept with Tab. But Charm also runs Spells, which corrects spelling in real time as you type, and Polish, which corrects grammar at the end of each sentence. The three features work together, so a single app handles prediction, spelling, and grammar across every text field on your Mac.
Is Cotypist a subscription or a one-time purchase?
This is the difference most people notice first. Cotypist is a subscription. There is a free tier with a daily word limit, and paid plans start at around $6 per month, with a higher tier for the full model catalog and multi-Mac use. There is no one-time or perpetual licence - if you stop paying, the paid features stop.
Charm costs $9.99 once. One payment, and the app is yours indefinitely, with a single licence covering up to 3 Macs and updates included. There is no monthly charge and no feature tier withheld behind an upgrade. Over a year, Cotypist's entry plan costs roughly $72; over three years, more than $200. Charm is a single $9.99 payment over the same period.
Does Cotypist work on Intel Macs?
No. Cotypist requires an Apple Silicon Mac - an M1 chip or newer - and recommends 16GB of RAM, because it runs a local language model that is demanding on hardware. If you have an Intel Mac, Cotypist is not an option at all.
Charm runs on both Intel and Apple Silicon Macs, on macOS 14 Sonoma or later. If you are on an older Intel MacBook or iMac that is still doing its job perfectly well, Charm works and Cotypist does not. This is a meaningful gap for anyone not yet on Apple Silicon.
| Feature | Charm | Cotypist |
|---|---|---|
| Word prediction | Yes - Oracle | Yes - its core focus |
| Real-time spelling correction | Yes - Spells | Light typo fixing only |
| Grammar correction | Yes - Polish | No |
| On-device and private | Yes | Yes |
| Runs on Intel Macs | Yes | No - Apple Silicon only |
| Works in code editors and Terminal | Yes | Limited - excluded by default |
| Pricing | $9.99 once | Subscription from ~$6/month |
| Requires macOS version | macOS 14 Sonoma+ | macOS 14 Sonoma+ |
Where does each tool work?
Both tools use the macOS Accessibility API to operate system-wide, so they appear in most native apps and browsers. There are differences at the edges that matter for some workflows.
Cotypist is designed primarily for prose: email, Slack, Notes, documents, and AI prompt boxes. By default it excludes code editors' main editing area and Terminal, and a few environments (such as Google Docs and some browsers) need extra setup. That is a sensible choice for an autocomplete tool aimed at writers, but it means developers do not get prediction in the place they type most.
Charm is built to work everywhere you type, including code comments, commit messages, and Terminal, using the Accessibility API together with a CGEventTap at the keyboard-event level. For a developer who wants correction in an IDE and a writer who wants it in Mail, the same install covers both.
Are both tools private?
Yes, and this is worth stating plainly: both Charm and Cotypist process your text entirely on your Mac. Neither sends your keystrokes to a server, neither requires an account to function, and both work offline. If your main reason for avoiding cloud tools like Grammarly is privacy, either of these tools solves that problem. This is not a point of difference between them - it is something they share and both do well.
Where does Cotypist have the edge?
Cotypist's single-minded focus is its strength. Because prediction is the entire product, its ghost-text autocomplete is highly polished, and its voice personalisation - learning to predict longer passages in your own style - is the heart of what it does. If word prediction is the only feature you want, and you want the most refined version of it, Cotypist is a strong, mature choice from a trusted indie developer.
Charm's Oracle prediction is one of three features rather than the whole app, so a prediction purist may prefer Cotypist's depth. The trade-off is that Cotypist asks for a recurring subscription and does not correct spelling or grammar, while Charm bundles prediction with correction for a one-time price.
Frequently asked questions
What is the difference between Charm and Cotypist?
Cotypist is a focused autocomplete tool that predicts your next words and sentences. Charm does word prediction too (Oracle), but also adds real-time spelling correction (Spells) and grammar correction (Polish). Cotypist is a subscription; Charm is a one-time $9.99 purchase. Charm also runs on Intel Macs, while Cotypist requires Apple Silicon.
Is Cotypist a subscription or a one-time purchase?
Cotypist is a subscription. It has a free tier with a daily word limit, and paid plans start at around $6 per month. There is no one-time option. Charm is a single $9.99 payment with no recurring charge.
Does Cotypist work on Intel Macs?
No. Cotypist requires an Apple Silicon Mac (M1 or newer) and recommends 16GB of RAM. Charm runs on both Intel and Apple Silicon Macs on macOS 14 Sonoma or later.
Does Cotypist correct spelling and grammar?
Cotypist focuses on autocomplete and includes light typo fixing, but it does not do sentence-level grammar correction. Charm includes both Spells (spelling) and Polish (grammar) alongside Oracle word prediction.
Are Charm and Cotypist both private and on-device?
Yes. Both run entirely on your Mac with no cloud calls, so your text never leaves your device. The differences are scope, pricing, and hardware support, not privacy.