Language Reactor — originally Language Learning with Netflix — is the extension that made dual subtitles popular. If you learned Korean from a drama or Spanish from a telenovela in the last five years, there is a good chance it was on. It is still a very good tool for what it was built for: Netflix and YouTube.
The searches for a Language Reactor alternative almost always come from the same four places, and it helps to know which one is yours before you pick a replacement:
- It doesn't work on your streaming service. Language Reactor supports Netflix and YouTube. It does not work on Amazon Prime Video, HBO Max, Disney+, Crunchyroll, Apple TV+ or Paramount+. This is by far the most common reason.
- The translation quality. The second subtitle line is machine-translated with Google Translate, which is fine for plain sentences and weak on slang, idioms and anything sarcastic.
- You want fewer features, not more. The interface is built for study sessions. If you just want to understand the show, it gets in the way.
- Mobile or TV. Nobody solves this one — every tool on this list is a desktop browser extension, Language Reactor included. If that is your blocker, no alternative helps.
Disclosure first: I build Sublo, one of the tools below. I have tried to keep the comparison fair, and where Language Reactor or another tool is the better pick, I say so.
The short version
Stay with Language Reactor if you only watch Netflix and YouTube and you use its vocabulary tools. Switch to Sublo if the show you want to watch is on Prime Video, HBO Max, Disney+ or Crunchyroll, or if you mainly want a cleaner translation and no study interface. Trancy is the closest feature-for-feature clone with AI translation, Migaku is for people who live in Anki, and LingQ is a reading platform rather than a subtitle tool.
Platform support: Language Reactor vs Sublo
Since platform coverage is the number-one reason people switch, here it is service by service. This is the comparison that decides it for most people.
| Streaming service | Language Reactor | Sublo |
|---|---|---|
| Netflix | Yes | Yes |
| YouTube | Yes | Yes |
| Amazon Prime Video | No | Yes |
| HBO Max | No | Yes |
| Disney+ | No | Yes |
| Crunchyroll | No | Yes |
| Apple TV+ | No | Yes |
| Paramount+, Peacock, Hulu, MUBI, Plex | No | Yes |
Trancy and Migaku sit in between: both list Netflix, YouTube and Disney+ (plus a few education sites in Trancy's case), but neither covers Prime Video, HBO Max or Crunchyroll. Platform lists change, so check the vendor's own page before you pay for anything.
All five tools at a glance
| Tool | Platforms | Translation | Free plan | Paid (approx.) |
|---|---|---|---|---|
| Language Reactor | Netflix, YouTube | Google Translate | Yes, generous | ~$5/mo for Pro features |
| Sublo | 12+ services (see table above) | Gemini AI, 50+ languages | Yes, daily allowance, no account | €2.89/mo billed yearly, or €3.89 monthly |
| Trancy | Netflix, YouTube, Disney+, some course sites | Several engines incl. AI | Limited, account required | ~$5–10/mo |
| Migaku | Netflix, YouTube, Disney+ | Google Translate + dictionaries | Trial only | ~$10–15/mo |
| LingQ | Imported text/audio, YouTube | Built-in dictionary | Limited | ~$13/mo |
Competitor prices are approximate and change; Sublo's are current as of September 2026.
Language Reactor: still the best study tool for Netflix
Credit where it is due. Language Reactor's Netflix integration is mature: hover a word for a dictionary popup, save phrases, export to Anki, auto-pause after each line, a sidebar transcript you can scroll through. For a learner who treats an episode as a study session, that workflow is hard to beat, and most of it is free.
Its limits are equally clear. Outside Netflix and YouTube it does nothing — there is no partial support, the extension simply does not activate on Prime Video or HBO Max. The second subtitle line comes from Google Translate, so character voice and slang flatten out. And the amount of UI it adds is a feature for studying and a bug for watching.
Sublo: dual subtitles on every major service
Sublo does one thing: it reads whatever subtitle track the streaming service is playing and shows a second, translated line under it, in real time, on Netflix, Prime Video, HBO Max, Disney+, Crunchyroll, YouTube, Apple TV+, Paramount+, Peacock, Hulu, MUBI and Plex. Translation runs through Gemini AI, which handles idioms and tone noticeably better than Google Translate, into any of 50+ languages. There is no account, no study sidebar, and each subtitle line can be styled and positioned separately.
What Sublo does not have: phrase saving, dictionary popups, Anki export. If those are the reason you use Language Reactor, Sublo is a complement (many people run both) rather than a replacement. If the reason you are here is “it doesn't work on the show I want to watch”, it is the direct fix. Full comparison: Sublo vs Language Reactor.
Trancy: the closest clone
Trancy copies the Language Reactor idea and adds AI translation, a choice of engines and its own learning features. It is strongest on YouTube and also supports Netflix and Disney+. The trade-offs: an account is required, the free tier is tight, and it is another feature-heavy interface. Good pick if you want Language Reactor's study workflow with better translation on YouTube. Sublo vs Trancy.
Migaku: for serious immersion learners
Migaku is a paid suite built around Anki-style spaced repetition: sentence mining, frequency lists, card creation with audio and screenshots. Dual subtitles are one piece of a much larger workflow. If you already spend an hour a day in Anki, the price is justified. If you just want to watch, it is overkill. Sublo vs Migaku.
LingQ: not really a subtitle tool
LingQ shows up in every “alternatives” list, but it is a reading-and-listening platform with a library of lessons and word tracking. It can import YouTube videos; it does not add subtitles to streaming services. Worth knowing so you don't install it expecting Netflix support.
Which one should you pick?
- Netflix and YouTube only, and you use the vocabulary tools → keep Language Reactor.
- The show is on Prime Video, HBO Max, Disney+, Crunchyroll or Apple TV+ → Sublo. Nothing else on this list works there.
- You want better translation than Google Translate and a clean screen → Sublo.
- You want Language Reactor's study features with AI translation on YouTube → Trancy.
- You live in Anki → Migaku.
- You want structured lessons, not shows → LingQ.
None of these is mutually exclusive. They are separate Chrome extensions and they do not conflict, so a common setup is Language Reactor for Netflix study sessions and Sublo for everything else. If you are new to the idea of two subtitle tracks, the dual subtitles guide explains what to expect and how to set it up on each service.
Frequently asked questions
Does Language Reactor work on Amazon Prime Video?
No. Prime Video is not supported and there is no workaround inside Language Reactor. Sublo supports Prime Video in every region. Details: Does Language Reactor work on Amazon Prime?
Does Language Reactor work on HBO Max or Disney+?
No to both. For HBO Max see the HBO Max alternative; Disney+ works the same way with Sublo.
Does Language Reactor work on Crunchyroll?
No. Crunchyroll is a frequent request because anime learners want Japanese plus their own language at once. Language Reactor alternative for Crunchyroll.
Is there a free Language Reactor alternative?
Sublo has a free plan with a daily allowance and no account. Trancy has a limited free tier behind a sign-up. Migaku is trial-only.
Can I use Language Reactor and Sublo at the same time?
Yes. They don't conflict. Turn Sublo off on Netflix if you prefer Language Reactor's layout there, and let it run everywhere else.
Get dual subtitles on Prime Video, HBO Max, Disney+, Crunchyroll and Netflix — free plan, no account.
Install Sublo