AI subtitle translation in the browser

Podstr

Watch movies and TV shows in the original language with subtitles in yours. The extension translates right in the browser — via Claude, Gemini, DeepSeek.

YouTube, ARTE, Plex and more.

Install from Chrome Web Store Translate subtitles online GitHub
01 / Process

How it works

01
Install the extension in Chrome
02
Open a video on YouTube or another site
03
Pick the subtitle language in the picker above the video
04
Subtitles appear over the video

Where to watch

The extension intercepts subtitles from the HLS stream and YouTube. Tested on these services:

YouTube Interviews, shows, lectures — any video with manual subtitles (CC) Plex Your own media server or free ad-supported catalog with English subtitles ARTE European cinema and documentaries, subtitles in multiple languages Filmzie Free indie and classic films with English subtitles BBC iPlayer BBC series and documentaries with subtitles Netflix soon Support in development
02 / Why

Why you need this

Original voices
Dubbing is a compromise. Podstr translates subtitles while you hear how the actors actually sound. Accents, intonations, original humor.
Not Google Translate
Translation via Claude, Gemini, DeepSeek — models that understand dialogue context, humor, slang. Not perfect, but leagues ahead of machine translation.
Any language → any language
English, Spanish, German, Finnish subtitles — translates into Russian, Ukrainian, or any of 30 languages.
Original + translation
Dual subtitles — original and translation at the same time. Great for language learning or when you want to hear the original and understand every word.
04 / Honestly

What AI subtitles can and can't do

Is this a replacement for professional translation?
No, but the quality is very decent. Podstr translates existing subtitles — clean text, not a speech-to-text transcript. This is fundamentally better than AI subs generated from audio: no recognition errors, no garbled words.
How good is the translation?
Claude Sonnet delivers the best quality — humor, slang, context all on point. Via OpenRouter you can choose a model: DeepSeek and Gemini start from a penny per episode, Claude Haiku offers excellent value.
Where does AI translation stumble?
The same places a human translator would struggle with text-only input. The model can't see the picture — it doesn't know if a man or woman is speaking, so gendered forms may be wrong. Neologisms like “herstory” might be translated literally. These are format limitations, not model limitations.
Do I need an API key?
You need an OpenRouter API key to translate. Registration is free, pay per token — from a penny per episode.
05 / Install

Get started in 2 minutes

Main path

Installation

Chrome + OpenRouter API key

  1. Install the extension from Chrome Web Store
  2. Paste your OpenRouter API key in extension settings
  3. Open a video with subtitles — the extension translates automatically

One click — and the extension is ready. Auto-updates included.

06 / Open source

The project is open

All code is open source, the extension is free. Join in — bug reports, ideas and PRs are welcome.

GitHub Documentation
07 / History

Changelog

  • 2026-03-19 feat BBC iPlayer support. Translation cost shown after completion. Slow model warning. Animated progress bar before first results
  • 2026-03-14 feat Version 0.6 — keyboard shortcuts work on any layout, improved YouTube SPA navigation, translated subtitles auto-move to top when native CC enabled
  • 2026-03-13 feat Smart overlay — translation progress bar right on the video, extension adapts to your account. Better subtitle language picker
  • 2026-03-12 feat Email sign-in — 5 free translations per month without an API key. Pricing and platforms pages on the site
  • 2026-03-11 feat Model picker with pricing — per-episode translation cost visible at a glance
  • 2026-03-04 feat 30 translation languages and UI in 13 languages — Arabic, Hindi, Swedish, Czech and more. Default language detected automatically
  • 2026-03-02 feat YouTube support — translate manual subtitles (CC) right on YouTube
  • 2026-02-24 feat Shared cache — if someone already translated an episode, the translation appears instantly
  • 2026-02-17 feat Translation via OpenRouter — the extension works standalone, just paste an API key
  • 2026-02-16 feat First release — the extension intercepts subtitles from video sites, translates with AI and displays them over the video