Zember Ember — offline AI for your Android phone

Qwen3.5 4B running entirely on your Android phone. Read a contract or a photo and ask about it; nothing is uploaded, it works offline.

Check your phone before you buy

Android 13 or newer, 64-bit
Almost every Android phone sold since 2019.
8 GB of RAM or more
Settings → About phone shows it.
About 3 GB of free storage
And Wi-Fi once, for the first-run download.
A separate product
The key opens Zember Ember on the phone. The PC models are sold separately.

Photograph a page and ask about it
A real OCR engine reads printed text, so numbers, codes and decimals come out as printed.
Your documents
Add a PDF or a photo and ask questions about it. It answers from your text, and says plainly when the answer is not in there.
Solve, Explain, Quiz
Three working modes besides your documents.
Nothing leaves the phone
No account, no cloud. We ran it on a Galaxy S25 Ultra, offline.

Does it work without internet?
Yes. After the one-time brain download on first launch it never uses the network again. Put the phone in airplane mode and everything still works.
Where do my documents go?
Nowhere. They are read on the phone and the text stays in the app's private storage. The app contains no code that uploads what you open.
Is this a ChatGPT wrapper?
No. There is no API call, no key and no account. The language model file sits on your phone and runs on your phone.
Why does it download 2.5 GB?
That file is the brain, the part that does the thinking. It comes down once, over Wi-Fi.
Can it read a scanned contract?
Yes. PDFs are rendered page by page and read with OCR, so scanned documents work like digital ones.
Will it invent numbers?
It reads printed text with an OCR engine rather than guessing it from the image, and it is told to quote numbers exactly and to say when something is not in the text. Check anything important against the page.
Is there a subscription?
No. One payment. The app has no account system, so it has no way to charge you again.
Does it replace a lawyer or an accountant?
No. It reads and summarises what is in your documents. It does not give professional advice.

Qwen3.5 4B Q4_K_M
About 2.5 GB, Apache 2.0, downloaded once from the people who made it.
llama.cpp (MIT) and Tesseract OCR (Apache 2.0)
The full list is in the app, under About.