Bonsai Image
On-device AI image generation for Android. A single APK that runs a diffusion model entirely on your phone's GPU via WebGPU — no accounts, no servers, no cloud.
This repo hosts the all-inclusive APK (~2.5 GB, model bundled inside) because it's over GitHub's 2 GB release-asset limit.
Download
⬇️ Bonsai-Image.apk (~2.5 GB)
- Enable Install from unknown sources on your Android device.
- Download and open the APK.
- Type a prompt (or attach a photo for image-to-image) and tap Generate.
Requirements
- Android 12+ with a recent Android System WebView / Chrome (121+)
- A Qualcomm Adreno or ARM Mali GPU (most modern phones)
- ~3 GB free storage
- WebGPU support in the system WebView — the app reports this in Settings → Device
How it works
| Layer | Detail |
|---|---|
| UI | Single-file WebView app, dark theme, on-device history (localStorage) |
| Engine | SD-Turbo via onnxruntime-web on the WebGPU execution provider |
| Model | fp16 ONNX (text encoder + UNet + VAE), bundled in the APK |
| Tokenizer | CLIP, via @xenova/transformers |
Generation runs locally. First launch fetches a small (~25 MB) GPU runtime once, then it's fully on-device.
Status — experimental
This is an early build. The current engine is SD-Turbo, used as a working stand-in. PrismML's Bonsai 1-bit/ternary image model (a 1-bit quantization of FLUX.2 Klein) has no Android/WebGPU runtime yet; when one ships, it drops into the same engine slot and the app around it stays identical.
Installs alongside the separate Bonsai LLM text app — different package, violet icon.
License
The bundled SD-Turbo weights are governed by the Stability AI Non-Commercial Research Community License (see SD-Turbo). Non-commercial use only.
Model tree for alphastack1/bonsai-image
Base model
stabilityai/sd-turbo