Chrome Extension · Free · Open Source

Watch YouTube
in any language
powered by AI.

Real-time subtitle translation using free and open AI models. Works with any OpenAI-compatible API — or use our built-in free tier. Zero data collection.

↓ Add to Chrome — it's free See how it works
Live translation preview
The universe is under no obligation to make sense to you.
宇宙没有义务让你觉得它合乎情理。
Why YCCT

Everything you need, nothing you don't.

⚡
Real-time streaming
Translations stream in as the AI generates them. No waiting for the full batch to complete before you see results.
🤖
Any AI model
Works with OpenAI, Gemini, DeepSeek, or any OpenAI-compatible endpoint. Bring your own key or use the free built-in tier.
🔒
Privacy first
No accounts. No tracking. No data collection. Your API keys stay in your browser's local storage only.
🌐
40+ languages
Translate to Chinese, Japanese, Korean, Spanish, French, German, Arabic, and dozens more. Source language auto-detected.
🎨
Fully customizable
Adjust font size, color, opacity, and position. The translated captions sit cleanly below YouTube's native subtitles.
♻️
Smart preloading
Translates in 1-minute windows and preloads the next batch 30 seconds early. Seamless playback, no interruptions.
How it works

Simple setup, powerful results.

01
Install the extension
Add YCCT to Chrome from the Web Store. No account required. Works immediately after install with the free built-in AI tier.
02
Open any YouTube video with captions
Navigate to a YouTube video that has subtitles available. The extension detects caption data automatically.
03
Click the translate button
A translate button appears in the YouTube player controls. Click it to start. Translations appear below the native captions within seconds.
04
Configure your preferred AI (optional)
Open the side panel to add your own API key for OpenAI, Gemini, or DeepSeek. Or keep using the free tier — no configuration needed.
Compatible AI models
✦ Free built-in tier
OpenAI GPT-4o
Gemini 2.0 Flash
DeepSeek V3
Claude 3.5 Haiku
Any OpenAI-compatible API
✓
No data sold to third parties
✓
No tracking or analytics
✓
Keys stored locally only
Read our full privacy policy →