Manga translation that runs on your phone, bubbles and all

What it does

Manga Translator is a Kotlin Android app that takes a comic page, finds the speech bubbles and floating text, reads them (locally with TFLite/ONNX OCR models, or via a cloud OCR API), translates with an LLM, and renders the translated text back into the original bubbles. It’s also a full reader and library manager — CBZ/ZIP/PDF import, webtoon scrolling, reading progress — plus a floating overlay that translates whatever is on your screen in other apps.

The interesting bit

The pipeline is genuinely hybrid: bubble detection and OCR run on-device (a YOLO26s-seg TFLite model for bubbles, PaddleOCR models for text lines), while translation requires you to bring your own AI API. There’s also a “full-text fast translation” mode that maintains a rolling glossary and plot summary across pages, so character names stay consistent through a whole volume — a detail most translation tools ignore.

Key highlights

• Three translation modes: standard detect→OCR→translate, VL direct translation (send the image to a vision model), and glossary-aware full-text mode
• Cross-page context: merge up to hundreds of pages per request while still saving results page-by-page
• On-device OCR for Japanese, English, Chinese, and Korean; Russian requires an API
• Floating overlay translates other apps’ screens, with translucent pass-through or opaque modes
• Target language follows the UI language: Chinese (simplified/traditional), English, Brazilian Portuguese, Russian
• Separate backups for library+translations and app config (including API keys — handle with care)

Caveats

• Translation is not offline: you must configure your own OpenAI-compatible, Responses, or Gemini API — the app is detection/OCR local, translation cloud
• If Android kills the app mid-job, translation does not resume automatically; you re-trigger it manually (though cached work is reused)
• The README notes the image pipeline isn’t pixel-identical to the upstream OpenCV/PyTorch implementations — a candid disclaimer

Verdict

Worth a look if you read untranslated manga on Android and already pay for an LLM API. If you wanted a fully offline translator, the OCR is local but the brain still isn’t.