Translate subtitles into any language with AI. Chrome extension: detects subtitles on video platforms and translates them in real time.
Website · Chrome Web Store · Telegram
🇷🇺 Русский · 🇺🇦 Українська · 🇧🇾 Беларуская · 🇷🇸 Srpski · 🇪🇸 Español · 🇫🇷 Français · 🇩🇪 Deutsch · 🇧🇷 Português · 🇨🇳 中文 · 🇯🇵 日本語 · 🇰🇷 한국어 · 🇹🇷 Türkçe
A Chrome extension that intercepts subtitles on video sites and translates them using AI models (Claude, Gemini, DeepSeek, etc. via OpenRouter). Works with English, Spanish, German, Finnish — any subtitles. Translates into any language.
If someone has already translated the same episode, the translation loads from a shared cache — instantly and for free.
- Install from Chrome Web Store
- Open a video with subtitles → pick a language → done
To translate new content, you need an OpenRouter API key (free keys available).
| Platform | Subtitles | Status |
|---|---|---|
| YouTube | Manual CC (not auto-generated) | Tested |
| BBC iPlayer | TTML/EBU-TT-D | Tested |
| ARTE | HLS subtitles | Tested |
| Plex | HLS subtitles | Tested |
| Filmzie | HLS subtitles | Tested |
| Netflix | HLS subtitles | Experimental |
Other sites with HLS/VTT/TTML subtitles may work — click Enable in the extension popup.
- Any language — translates from any subtitle language to any target language
- Multiple AI models — choose by quality and price. Free models available
- Translation cost — see how much each translation costs right on the video
- Shared cache — one person translates, everyone else watches for free
- Smart local cache — translated subtitles load instantly on repeat viewing
- Timing adjustment —
[/]to shift ±0.5s - Style customization — font, color, opacity, position
- Keyboard shortcuts —
Btoggle position,\reset offset - 13 interface languages — EN, RU, UK, BE, SR, ES, FR, DE, PT, ZH, JA, KO, TR
- Detection — service worker intercepts subtitle requests via
chrome.webRequest - Download — background script fetches subtitles, bypassing CORS
- Translation — batched via OpenRouter API (your key, your choice of model)
- Cache — translated VTT compressed with gzip, stored locally + shared cache
- Render — content script displays subtitles synced with video playback
Do I need an API key? No, if the episode is already in the shared cache. For new translations — you need an OpenRouter key.
Is it free? The extension is free. Cached translations are free. You only pay for translating new content via the AI provider.
Translation quality? Depends on the model. Claude Opus is on par with good fansubs. DeepSeek and Gemini Flash are cheaper but still readable.
Typical cost? $0.005–0.05 per episode depending on the model. Free models available.
- Your API key stays on your device — never sent to any server
- No tracking, no analytics, no ads
- Subtitle text is sent only to the AI provider you choose
- Privacy policy
See CONTRIBUTING.md
MIT
- podstr.cc — website
- Translate subtitles online — no extension needed
- Chrome Web Store
- GitHub
- Telegram