Hemmingway is a small AI lab and the writing app it makes. It trains its own model, Hemmingway-1, for writing that sounds like a person wrote it: messages, emails, replies, letters and short stories. The name is spelt with two m's. Hemmingway is not connected to the writer Ernest Hemingway, and it is not the Hemingway Editor, a readability checker from another company.
At a glance
| What it is | An AI lab, its model and its apps |
|---|---|
| Brand | The Commons Lab |
| Run by | Luka Simonovic, trading as Altworld.io |
| Based in | Bülach, Switzerland |
| Model | Hemmingway-1: 27 billion parameters, open weights under CC BY-NC 4.0 |
| Apps | Mac, Windows, Android and the browser |
| API | OpenAI-compatible, at https://hemmingway.io/v1, model id hemmingway-27b |
| For adults | Hemmingway Unlocked, at wise.hemmingway.io |
| Your writing | Chats, memory and People are never used for training |
| Contact | support@hemmingway.io |
What we make
- Hemmingway-1, our model. 27 billion parameters, built on Qwen3.8-27B, with 262,144 tokens of context. The weights are open under CC BY-NC 4.0: free for non-commercial use, and commercial use by agreement. They are on Hugging Face, and the code is on GitHub.
- The Hemmingway app, for Mac, Windows, Android and the browser. It writes in your voice, and it can read your mail and chats and draft replies the way you would, asking before anything goes out in your name.
- The API, an OpenAI-compatible endpoint for Hemmingway-1. The docs show how to connect.
- Hemmingway Unlocked, the adults-only side: an uncensored model for explicit and dark fiction, roleplay and chat, with a short list of things it never writes. It is free to try, and its chats stay in your browser.
- Free writing tools and guides: forms that open the app with your request filled in, and plain guides to writing messages, speeches, emails and stories.
How we test
We test Hemmingway-1 against the largest models available. One test is public; three are our own, and we say so wherever we quote them. The model card has every number and how each test works.
| Test | What it measures | Hemmingway-1 |
|---|---|---|
| EQ-Bench 4 | Emotional intelligence, a public benchmark run with its official harness | 1330, third of 27 |
| CommunicationBench | Our blind test of everyday messages and emails | 1026, first |
| Human-Likeness | Same test: which one did a person write? | 1032, first |
| StoryBench | Our creative-writing test | 1197, level with Kimi K3 |
For long fiction, the big story models are better. Hemmingway-1 is English-first, it can be wrong and sound sure, and it is not for medical, legal or financial decisions.
What we do with your writing
We do not train our models on your chats, your memory or the People you keep, and we do not sell them. In Hemmingway Unlocked, chats are kept in your browser and never reach your account. The privacy policy says what is kept and where.
Who runs it
Hemmingway is brought to you by The Commons Lab. The Commons Lab is our project and brand name; it is not a separate company. The service is operated by Luka Simonovic, trading as Altworld.io, Mittlere Gstücktstrasse 21, 8180 Bülach, Switzerland, and Swiss law applies. The terms and the privacy policy set this out in full.
Where to find us
- Help, privacy questions and anything else: support@hemmingway.io
- Commercial licensing of the weights: team@hemmingway.io
- Hugging Face and GitHub
- X, Instagram, Reddit and TikTok
Common questions
Who makes Hemmingway?
Hemmingway is made by The Commons Lab, a small AI lab. The service is operated by Luka Simonovic, trading as Altworld.io, in Bülach, Switzerland. The lab trains its own model, Hemmingway-1, and builds the Hemmingway apps, the API and Hemmingway Unlocked.
Is Hemmingway the same as Ernest Hemingway or the Hemingway Editor?
No. Hemmingway is spelt with two m's and has no connection to the writer Ernest Hemingway. The Hemingway Editor, with one m, is a readability checker from a different company. Hemmingway writes the text for you; the Hemingway Editor marks up text you have written.
Where is Hemmingway based?
In Bülach, Switzerland. The service is operated from there, and Swiss law applies to it, without removing the consumer protections that the law where you live requires.
Is Hemmingway-1 open source?
Its weights are open under the CC BY-NC 4.0 licence, so you can download, run and fine-tune it for non-commercial use. Commercial use needs a written agreement; write to team@hemmingway.io. The uncensored model behind Hemmingway Unlocked is not published yet; we plan to open-source it soon.
Does Hemmingway train on my chats?
No. Your chats, your memory and the People you keep are never used for training, and they are never sold. Chats in Hemmingway Unlocked stay in your browser and never reach our servers to be kept.
How do I contact Hemmingway?
Write to support@hemmingway.io for help, privacy requests or anything else. For commercial licensing of the model weights, write to team@hemmingway.io.