あ Subbun
Chrome extension · 100% on-device

Japanese video, in English.

Watch Japanese TV, anime, and drama with instant English subtitles. Turn on Japanese captions on the site, and Subbun translates them live — entirely in your browser. Your content never leaves your computer.

Add to Chrome See how it works

Free on YouTube · 14-day Pro trial on every other site · No credit card required

Japanese TV in English — Abema, TVer, NHK, U-NEXT, Netflix.

No other extension reaches Japanese streaming sites. Subbun is the only way to watch Abema dramas, TVer catch-up, or NHK documentaries in English — without uploading your video to any server.

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Japanese TV sites
Abema, TVer, NHK Plus, U-NEXT — none supported by any other tool. Subbun reads captions directly from the player.
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100% private
Translation runs in Chrome via on-device Gemini Nano. Subtitle text never leaves your machine — no API keys, no cloud calls.
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Natural English
Learns character names and pronouns from each episode. Translates Japanese grammar in full sentences, not word-by-word.

Live English subtitles, on every Japanese video site.

Turn on the platform's Japanese captions. Subbun reads them, translates them on-device with Chrome's built-in Gemini Nano AI, and overlays the English right under the video. No menus, no API keys, no setup.

  • ✓ 9 sites supported — including Abema, TVer, NHK Plus, and U-NEXT that no other tool reaches.
  • ✓ Names and genders learned per episode — Misaki stays Misaki, pronouns are right for her character.
  • ✓ Alt+E explain this line — pause and get a grammar breakdown in one keystroke.
  • ✓ Netflix lines pre-translated — subtitles appear the moment a line starts, not after it finishes.
  • ✓ 100% on-device — subtitle text never leaves your machine. No servers, no API keys.

Requires Japanese captions to be turned on in the video player. Needs Chrome 138+ on a desktop machine with ≥16 GB RAM and ≥22 GB free disk for the full Gemini Nano experience; a lighter translation mode works on most hardware.

Add to Chrome
LIVE · ABEMA
田中さん、本当に大丈夫ですか？
Tanaka-san, are you really okay?
Works on
YouTube Netflix Amazon Prime Abema TVer NHK Plus U-NEXT Hulu Japan Crunchyroll

Simple pricing.

Free on YouTube forever. Pro unlocks every other supported site.

Free

YouTube only. Translation runs on your device.

$0 forever
  • ✓ YouTube unlimited
  • ✓ All translation engines
  • ✓ Native English subtitle overlay
  • ✓ No card required
Add to Chrome
14-day trial

Pro Monthly

Every supported site, full Gemini Nano translation.

$4.99 / month
  • ✓ All 9 sites unlocked
  • ✓ Anime / drama / news presets
  • ✓ Custom glossary + character names
  • ✓ Alt+E explain this line
  • ✓ Cancel anytime
Start 14-day trial

Pro Annual

Same as monthly — about 35% off for the year.

$39 / year
  • ✓ Everything in Pro Monthly
  • ✓ 2 months+ free vs monthly
  • ✓ 60-day refund
  • ✓ Cancel anytime
Start 14-day trial

Lifetime

Founder deal — pay once, use forever. Price will rise.

$59 once
  • ✓ Everything in Pro
  • ✓ All future site additions
  • ✓ 60-day refund
  • ✓ Audio Mode credits sold separately
Get Lifetime

Common questions

More on the help page.

Is translation really on-device? Where does my data go? +
Yes. Subbun uses Chrome's built-in AI (Gemini Nano + Translator API), which runs in your browser process. Subtitle text never leaves your computer. The only thing we send to our servers is an anonymous license instance ID for Pro validation, and you can opt out of usage stats entirely.
What Chrome version do I need? +
Chrome 138 or newer on desktop (Windows, macOS 13+, Linux, ChromeOS). Chrome for Android/iOS doesn't expose the on-device AI APIs yet, so the extension can't work there.
Will it work on Netflix / Crunchyroll / [specific site]? +
Currently supported (9 sites): YouTube, Netflix, Amazon Prime, Abema, Crunchyroll, TVer, NHK Plus, U-NEXT, and Hulu Japan. Each site needs to expose Japanese subtitles as text in the DOM — we don't transcribe audio. If your favourite JP site isn't on the list, email us and we'll prioritize it.
Why isn't it free forever? +
YouTube is free forever. We charge for the other sites because each one is ongoing engineering effort — sites change their player DOM regularly and we ship patches. The subscription funds the maintenance.
Can I cancel? Is there a refund? +
Yes to both. Monthly cancellations take effect at the end of the billing cycle. Lemon Squeezy (our merchant of record) offers a no-questions 60-day refund on lifetime and annual purchases.
Does it work outside Japan / with VPN? +
Yes. Subbun runs entirely in your browser — there's no geo-restriction on our side. Some Japanese streaming sites (TVer, NHK Plus, U-NEXT) are themselves geo-restricted to Japan; using a VPN is between you and them.

Watch Japanese the easy way.

Free on YouTube. 14-day Pro trial on everything else. Install in 30 seconds.

Add to Chrome