RTranslator is an offline, real-time translation app for Android, enabling seamless conversations between users via Bluetooth. It targets individuals needing to communicate across language barriers, offering a privacy-focused, on-device solution.

How It Works

The app leverages Meta's NLLB for translation and OpenAI's Whisper for speech recognition, both optimized for on-device execution. Audio is captured, converted to text, translated, and then synthesized back into speech, facilitating bidirectional communication. Conversation mode supports multi-device connections, while WalkieTalkie mode offers quick, single-phone translations.

Quick Start & Requirements

• Install via APK from releases.
• Requires Android.
• Initial download of AI models is 1.2GB.
• Recommended: 6GB RAM and a fast CPU for optimal performance.
• Official Docs

Highlighted Details

• Utilizes NLLB-Distilled-600M and Whisper-Small-244M models, optimized to 1.3GB (NLLB) and 0.9GB (Whisper) RAM usage.
• Achieves 4x faster NLLB execution and 1.2x faster Whisper execution compared to standard ONNX models.
• Supports over 30 languages, with an option for lower-quality extended language support.
• Operates in the background and offline, ensuring privacy.

Maintenance & Community

• Developed by niedev.
• Bug reporting via GitHub issues or email: contact.niedev@gmail.com.

Licensing & Compatibility

• RTranslator code is open-source.
• NLLB model is open-source but restricted to non-commercial use.
• Ml Kit (language identification) is closed-source.
• Other libraries are open-source.
• Compatibility with commercial use is restricted due to NLLB's license.

Limitations & Caveats

The app is in beta, with reported Bluetooth connection drops. Background operation may be limited by phone power management. The use of closed-source Ml Kit for language identification is a potential concern for fully open-source purists.