Rewrite anything on your Mac without sounding like a robot wrote it.
Highlight a sentence in any app, press one key, and get it back fixed, tightened or re-toned — in your handwriting, so to speak. The point is that nobody can tell you used anything.
Rewrites fixes, tightens or re-tones any text you have selected, anywhere on macOS, from a single keystroke. Grammar and clarity are the easy part. The difference is the Voiceprint that Stilou builds from your own writing, so the corrected sentence still sounds like the person who wrote it rather than like a language model being helpful.
How do you rewrite text on a Mac?
There are three usual answers. Recent versions of macOS ship Writing Tools: select text, right-click, and choose Proofread, Rewrite, Friendly, Professional or Concise. Grammarly installs a system-wide layer that underlines mistakes as you type and suggests replacements. Or you paste the paragraph into a chat window, ask for a better version, and paste it back.
Each of these does something real. Writing Tools is free, instant and already on your Mac. Grammarly is the best pure error-catcher there is — comma splices, subject-verb disagreement, the tense you slipped out of three clauses ago — and it has been doing that for over a decade. Chat gives you the most control, because you can argue with it.
They also share one failure, and it is the reason "humanise AI text" is now a search people type. Every one of them rewrites towards the same middle. Contractions get expanded, jokes get sanded off, the specific noun becomes the general one, and three drafts later everything you write has the same faintly corporate hum. Readers have got fast at spotting it. The text is not wrong; it just is not yours, and being caught using it is worse than the typo you were fixing.
Stilou takes the other route. It builds a Voiceprint from your own writing — how long your sentences run, whether you use em dashes, which words you actually reach for — and rewrites towards that instead of towards a neutral register. The grammar still gets fixed. The difference is that the fixed version reads like you on a good day, which is the only version worth sending.
How to rewrite text with Stilou
It works on a selection, so the whole interaction happens inside the app you are already in.
- Select the text, anywhereA sentence in Mail, a paragraph in Notion, a Slack message you have not sent yet, a comment in your editor. Any app that lets you highlight text is an app this works in.
- Press the rewrite hotkeyOr press ⌥Space to open the Bar with your selection already loaded, if you would rather say what you want in your own words instead of picking from a list.
- Choose what should changeFix it, tighten it, warm it up, cool it down, make it shorter, make it a reply. Or type the instruction: "say no without being rude", "same thing, half the length", "less keen".
- Accept itThe new text replaces your selection in place. ⌘Z puts the original back, exactly like undoing anything else, so nothing is ever a one-way door.
Tip. The Voiceprint gets better the more of your own writing it has seen, so the first week is the worst it will ever be. If a rewrite comes back too polished, say "less polished" — that instruction sticks.
Why the output doesn't read as machine-written
It rewrites towards you, not towards neutral.
Sentence length, punctuation habits, the words you actually use and the ones you never do. Learned from your own writing, on your own Mac, and applied to every rewrite instead of a generic house style.
Warmer, cooler, shorter, firmer.
Tone is a dial rather than a personality transplant. "Firmer" makes the same argument with less hedging; it does not turn your email into a legal notice or add a paragraph you did not ask for.
The boring corrections still happen.
Typos, agreement, tangled clauses, the sentence that lost its main verb somewhere in the middle. You do not have to choose between being correct and sounding like yourself.
No copy, paste, switch, paste.
The rewrite replaces your selection inside the app you were in. There is no editor window to work in and no round trip through a browser tab, which is most of the reason people stop bothering.
Any app with selectable text.
Mail, Slack, Notion, Docs, Linear, an IDE, a browser form. No plugin per app, no supported-apps list, because it works with your selection rather than with an integration.
What you wrote stays findable.
Rewrites become dots in your local brain, linked to the people and projects they mention. The careful reply you spent ten minutes on is still there when you need the same argument again.
Stilou vs Grammarly vs Apple Writing Tools
Two of these are excellent at catching mistakes. The question is what the sentence sounds like afterwards.
| Stilou | Grammarly | Apple Writing Tools | |
|---|---|---|---|
| Catches grammar errors | Yes | Yes — the strongest of the three | Yes |
| Writes in your own voice | Yes, via your Voiceprint | House style | Neutral registers |
| Live underlining as you type | No — you invoke it | Yes | No |
| Tone control | Dial, plus plain-word instructions | Preset tones, paid tiers | Friendly / Professional / Concise |
| Works with no network | Yes, in Private mode | No | On-device on supported Macs |
| Works on Windows and the web | No — macOS only | Yes, everywhere | No |
| Keeps what you wrote | Yes — searchable, linked | No | No |
| Price | Free tier, paid plans for more | Free tier, paid for most of it | Free |
If you want a proofreader watching every keystroke and underlining errors before you finish the line, Grammarly does that and Stilou does not — you invoke Stilou deliberately. And if you work across Windows and the web all day, Grammarly follows you there and we do not. Come here when the problem is not that your writing has mistakes, but that every tool you use to fix them makes it sound like everyone else's.
Where the passage goes, and where your Voiceprint lives
In Private mode, the rewrite happens on your Mac. The model is local, the network is not involved, and the egress counter in the app stays at zero — which also means it works on a plane.
In Connected mode, only the passage you selected and your instruction go to a hosted frontier model from Anthropic or OpenAI. Not the document, not the rest of the thread, not your Voiceprint as a whole. If you bring your own API key, that request goes straight from your Mac to your provider and never touches our relay.
Your Voiceprint is a file on your own disk, built from your own writing. It is not uploaded, not shared, and not used to train anything — not by us, and not by the providers. Delete it and it is gone.
Frequently asked questions
Does this humanise AI text?
It rewrites text towards your own voice, which is the honest version of that request. Paste in something that reads as machine-written and Stilou will pull it back towards how you actually write — shorter where you are short, blunt where you are blunt. What it will not do is promise to defeat an AI detector, because nobody can promise that and the ones who do are guessing.
Is Stilou better than Grammarly?
For sounding like yourself, yes. For catching every comma error the instant you type it, no — Grammarly is a live proofreader with a decade of that behind it, and it works on Windows and the web where Stilou does not. Stilou is the better tool when the sentence is technically fine and still does not sound like you.
How does it learn my voice?
From your own writing. Stilou builds a Voiceprint out of the text you produce through it — sentence length, punctuation, vocabulary, the rhythms you repeat — and applies it to every rewrite. It improves with use, so the first week is the least like you it will ever be.
Does it work in any app?
Any macOS app where you can select text. Mail, Slack, Notion, Google Docs, Linear, your editor, a form in Safari. There is no per-app plugin, because Stilou acts on your selection rather than through an integration.
Can I undo a rewrite?
Yes — ⌘Z, like any other edit. The rewrite replaces your selection as a normal text change in the app you are in, so the original comes straight back and nothing is a one-way door.
Is my writing used to train an AI model?
No. Nothing you write is used for training, by us or by the model providers. Your Voiceprint is a file on your own Mac, and in Connected mode only the passage you selected is sent — never your whole document, and never the Voiceprint itself.
Does it work offline?
Yes, in Private mode, where the model runs on your Mac and no network is needed. Connected mode sends the passage to a hosted model for the harder rewrites, and the interface shows you which mode you are in.
What do I need to run it?
A Mac on a current version of macOS, and accessibility permission so Stilou can read your selection and put the new text back. There is a free tier, and local rewriting in Private mode runs best on Apple silicon.