🔒 Files never leave your browser
Your video is processed entirely on your device. Audio extraction happens locally, so the original file is never uploaded anywhere.
1. API Keys
2. Settings
Tone / Glossary (optional)
3. File
Drag video / audio / SRT files here, or click to select (multiple allowed)
Features
🎙️ Accurate speech recognition
Powered by Whisper large-v3-turbo, a state-of-the-art speech recognition model that transcribes Japanese, English, Chinese and more.
🌏 Context-aware AI translation
Claude AI translates each line while looking at the surrounding dialogue, producing natural conversational subtitles. Tone and glossary controls keep names and speech styles consistent.
🧹 Hallucination filtering
Fake lines that speech models invent during silence ("Thanks for watching", repeated sentences) are removed automatically.
📄 SRT translation support
Already have subtitles? Upload an SRT file to translate it directly. Failed lines are clearly marked so you can review them later.
💰 Pay only for what you use
The site is free — AI calls run on your own API keys. A one-hour video typically costs only a few cents to process.
How to use
- Get API keys — a Groq key (free tier) for extraction and an Anthropic key for translation. Keys are stored only in your browser.
- Pick languages and a model — choose the source language, target language, and translation quality. Haiku is usually enough for subtitles.
- Upload a file — drag in a video, audio, or SRT file and press Start.
- Download SRT — grab both the original and translated subtitles. Name the SRT after your video file and most players will load it automatically.
FAQ
Is my video uploaded to a server?
No. The video is processed inside your browser. Only the extracted audio is sent to Groq for transcription, and the subtitle text is sent to Anthropic for translation. The original video never leaves your device.
Are my API keys safe?
Keys are stored only in your browser's localStorage and are never sent to any server other than Groq/Anthropic themselves. On shared computers, clear the site data after use.
How much does it cost?
The site is free. AI usage runs on your own API keys — Groq has a free tier, and translating an hour of subtitles with Claude Haiku typically costs a few cents.
What file formats are supported?
Video: MP4, MKV, WebM, AVI and more. Audio: MP3, M4A, WAV, OGG. You can also upload an existing SRT file to translate it directly.
Can it handle long videos?
Yes — long videos are split into 10-minute chunks automatically and the timestamps are stitched back together. Very large files (several GB) may fail due to browser memory limits.