Fernfly adds a chat-style AI to your product — trained on your own features, running inside your app, with no per-message cost. Users ask for anything. Your app does the right thing.
From research to product
Fernfly is the commercial face of Fern — our on-device LLM research. The same compression that lets a 7B-quality model run on a smartphone is what lets Fernfly serve unlimited conversations at zero marginal cost.
Where Fern proves the technology, Fernfly puts it in the hands of developers: a tiny, task-specialised AI that turns natural language into the right action inside your product — no cloud, no per-message bill, no data leaving your app.
The lineage
7B-quality intelligence in a 750 MB footprint. Runs offline on phones, watches, and embedded chips.
Up to 60× smaller models with no measurable quality loss — across language, vision, and embeddings.
A tiny AI you train on your own app, drop in with one URL, and run for free — for every user, forever.
Like ChatGPT for your app — but free and private
Describe what your app can do, train in minutes, drop in a chat box. Your users get a natural-language interface; you get a model that knows your product, runs inside your stack, and doesn't bill per message.
No per-message fee. Train once, run as many conversations as you want.
Trained on your own features and APIs — not generic internet knowledge.
Runs inside your app. User conversations never go to OpenAI or anyone else.
Real conversations improve it automatically. The more users talk, the better it gets.
See exactly how it performs on every version. Know when it works and when it doesn't.
A single API call. Add it to any app — web, mobile, voice — in minutes.
Free to start. No credit card. Set up in an afternoon.