About Souffleuse
Souffleuse is a writing assistant for Mac that suggests the rest of your sentence, in grey under the cursor, in almost every app, for people who write all day and want their text to stay on their Mac.
Last updated: September 23, 2026 · version 0.12.2 (public beta).
What Souffleuse does
The rest of the sentence, in every app
When you hesitate, the continuation appears in grey under the cursor: in Mail, Notes, Messages, Slack, your browser. Tab takes it, Esc clears it, and if you keep typing it simply fades away. It also fixes typos in passing.
The “//” bar: fix, shorten, rephrase
Type // after some text to fix it, shorten it, rephrase it or change its tone, or
give a free instruction. At the start of a field, a few keywords are enough for it to write the
whole message, in French, English, Spanish, German or Italian. The result always shows as a
preview first: nothing is written without your say.
Translate as you write
Pick a conversation's language once: Souffleuse remembers it and translates as the exchange unfolds, in a small, quiet panel. Translation happens on your Mac, offline.
The usage ledger
A ledger counts the keystrokes saved and the time gained. It stays on your Mac, visible to you alone.
What changes compared with an online writing assistant
Your text goes nowhere
The language model runs on your Mac's Apple Silicon chip, using llama.cpp. No text is sent over the internet. After setup, everything works offline, on a plane or behind a corporate VPN.
No copy-pasting into a chatbot
Rephrasing and translation happen where you write, in the app's own text field. No extra tab, no pasting your email anywhere.
No subscription, no counter
The Studio license is a one-time purchase with no daily completion limit. For comparison, Cotypist's free tier is capped at roughly 100 completions per day, and unlimited use requires a subscription of about $6–9 per month (the comparison).
No account
You download, install and write. There is no sign-up, no login and no telemetry.
Who it's for
- People who write all day in someone else's app: Mail, Messages, Slack, a browser.
- Freelancers and support teams who answer lots of messages and want the right tone without spending the morning on it.
- People who write in several languages and want to translate without copy-pasting.
- Jobs where text must not go to a cloud: client data, confidential correspondence, locked-down company networks.
- Former Cotypist users who don't want a subscription for a typing tool.
You need an Apple Silicon Mac (M1 and later) running macOS Sonoma (14) or newer. Intel Macs are not supported.
Who makes Souffleuse
Souffleuse is made by Meffysto, an independent developer in France. He builds Mac and iPhone apps on his own, with no ads and no ad tracking, and shares the whole process in public on X.
Links: X (@Meffysto69) · GitHub (menufactory43) · legal notice
How it works
- Install: download the DMG from souffleuse.app (a 7.4 MB app, signed and notarized by Apple), drag it into Applications and grant the accessibility permission it asks for. On first launch it downloads its language model once (811 MB), then settles into the menu bar.
- Price: the download is free. The Souffleuse Studio license is a one-time purchase, €29 with Lightning or €39 by card (card payments through Lemon Squeezy). It unlocks translation, tone, “//” transformations and personalization. No subscription.
- Updates: from inside the app (Sparkle, signature verified).
- Support: write to contact@souffleuse.app.
- Data: everything stays on your Mac. The history used to learn your style is encrypted (SQLCipher, AES-256, key in the Keychain), logs contain no text, and screen capture for context is off by default. Details are in the privacy policy.
Key facts
- Name
- Souffleuse
- Type
- Writing assistant and 100% on-device AI autocomplete, in the Mac menu bar
- Platforms
- macOS Sonoma (14) or newer, Apple Silicon Macs (M1 and later). No Intel.
- Price
- Free download. Studio license, one-time purchase: €29 with Lightning, €39 by card. No subscription.
- Launched
- June 2026, as a public beta
- Engine
- llama.cpp on Metal, language model downloaded once (811 MB), then used offline
- Languages
- Suggestions follow the language you type. “//” drafting in French, English, Spanish, German and Italian. Website in French and English.
- Publisher
- Meffysto, independent developer, France
- Website
- souffleuse.app
- Contact
- contact@souffleuse.app
- Data / privacy
- 100% on the Mac. No text sent over the internet, no account, no telemetry. History encrypted at rest.
- Source code
- Public repository on GitHub: menufactory43/Souffleuse
- Other apps by the same maker
-
- Fauconnier: nine coding agents on a canvas, driven by voice. Mac (+ Perchoir on iPhone). Free.
- Daybard: your day replayed as an RPG epic in the evening. iPhone and Mac. Free.
- TimeVault: app blocker; you seal until a deadline, and it only opens on a proof. iPhone, Mac. Free, coming soon.
- Not a Cent: a directory of polished apps that haven't earned a cent yet. Web. Free.
- Lanes: read-only Git dashboard. Mac. Free, open source (MIT).
Frequently asked questions
Is Souffleuse free?
The download is free. Translation, tone, “//” transformations and personalization require the Studio license, a one-time purchase at €29 with Lightning or €39 by card. There is no subscription and no daily limit.
Does my text go over the internet?
No. The model runs on your Mac and Souffleuse works offline. It connects to download its model at setup and to activate a Studio license, never to send what you write.
Which Macs are supported?
Apple Silicon Macs (M1, M2, M3 and later) on macOS Sonoma (14) or newer. Intel Macs are not supported.
Which languages does it work in?
Suggestions follow the language you type, English included. Drafting from keywords offers French, English, Spanish, German and Italian.
Who is behind Souffleuse?
Meffysto, an independent developer based in France, who builds it on his own. He shares the work in public on X.
How is it different from Cotypist?
Cotypist pioneered system-wide autocomplete on the Mac and remains an excellent product. Souffleuse does the same thing with no subscription and no daily limit, and adds translation while you type, tone rewriting and a usage ledger, all running locally. See the full comparison.