Language Reactor vs Trancy vs Migaku (2026): Which One Should You Actually Use?

If you want to learn a language by watching YouTube or Netflix, three browser extensions dominate the conversation: Language Reactor, Trancy, and Migaku. They look similar in screenshots — dual subtitles, click-a-word dictionaries, some kind of flashcard feature — but they make very different trade-offs, and the right pick depends on what actually breaks your learning loop.

Short version: Language Reactor is the stable veteran with the most platforms, but its free plan won't let you save vocabulary anywhere useful. Trancy has the most generous free tier and the lowest price, but carries real quality problems. Migaku has the deepest study system and the only true mobile apps, at the highest price and with no free tier at all.

Here's the detailed comparison, based on each product's own pricing pages, changelogs, and Chrome Web Store reviews (checked June 2026; every price below was re-read from source on 5 October 2026, and none of the list prices had moved).

The comparison table

The fourth column is LingoKeep. Full disclosure: LingoKeep is ours — it's in the table so you can see where it sits next to the other three, and its limits are stated as plainly as theirs.

Free tiers and prices, answered directly

The most common questions about these three are "is it free" and "what does it cost," and the answers are less symmetrical than the table suggests:

• Is Language Reactor free? Partly. Dual subtitles and basic word lookup are free on YouTube and Netflix, indefinitely. What's not free is saving vocabulary across features — that needs Pro ($5.95/mo, or $39.95/yr ≈ $3.33/mo). So the free plan lets you understand but not keep. (Its Free-vs-Pro line in full, with every Pro price: is Language Reactor free?)
• Is Trancy free? Yes, and it's the most generous of the three: dual subtitles on every supported platform, unlimited lookups, subtitle downloads, plus a save cap of 100 words / 50 sentences. Paid (from ~$2.27/mo on the annual promo) buys AI transcription, unlimited saving, and the AI study features.
• Is Migaku free? No. There's a 10-day free trial and then it's $10/mo, $8/mo billed annually, or a $499 lifetime at list price — with no reduced tier for lighter use.
• Is Migaku worth it? It's worth it if you will genuinely use a full SRS every day, especially for Japanese, and you want native mobile apps — that combination is unique among the three. It's poor value if what you actually want is dual subtitles while you watch, because you'd be paying for courses and a study system you won't open.
• Is Migaku's lifetime plan worth it? Only on a long horizon: $499 is roughly five years of the annual plan, so it's a bet both on your own multi-year commitment and on the product outliving it. Most people are better served by the annual plan until they've proven the daily habit. One practical note: Migaku discounts the lifetime often — on 5 October 2026 some visits to its pricing page showed a sale price of $240, about two and a half years of the annual plan, while others showed the $499 list price — so if you do want it, wait for a sale rather than paying list.

Prices read off each product's own pricing page in June 2026 and re-read there on 5 October 2026 — all three list prices were unchanged. Discounts come and go (Trancy's annual promo and Migaku's lifetime sale both carry their own end dates), so treat these as of that second date.

Language Reactor: stable, broad, and older than it looks

Language Reactor (formerly "Language Learning with Netflix") is the incumbent: about two million Chrome users, support for Netflix, YouTube, podcasts, arbitrary web pages, and uploaded books, and a team that still ships small fixes every month.

What holds up well:

• The dual-subtitle experience is mature — it's been refined for years and covers 40+ languages, including transliteration for Japanese and other scripts.
• PhrasePump, its listening-first review mode, is a genuinely good idea: you review saved items by hearing them, not just reading them.
• Anki export with screenshots and audio has existed since 2020 and works.

Where it falls down:

• The free plan locks saving. You can watch with dual subtitles and look words up, but saving vocabulary across features requires Pro. That's the single most important step of the loop — the moment you decide a word is worth keeping — behind the paywall. In practice, free users watch, understand, and forget.
• You can't select a multi-word phrase. You can click one word or save the whole sentence, but not highlight "por si acaso" as a unit. For collocation-heavy languages this is a real gap, and it's a long-standing complaint in reviews.
• The interface is dense. "Overwhelming" is the recurring word in user reviews; the UI hasn't had a real redesign in years, and there's no native mobile app — reviews happen at your desk or not at all.

Pick Language Reactor if: you watch a lot of Netflix, you want the most platform coverage, and you're happy paying ~$3.33/mo (annual) from day one.

Trancy: the price aggressor with quality debt

Trancy is the fast-moving challenger. Its free tier is startlingly generous — dual subtitles on every major platform, unlimited dictionary lookups, even subtitle downloads. Its paid tier undercuts everyone at ~$2.27/mo on the perennial annual promo, and the AI bundle adds sentence explanations, a speaking coach, and pronunciation scoring.

What holds up well:

• The free tier covers what most casual learners need. If you just want dual subtitles and lookups, Trancy free does what Language Reactor Pro charges for.
• It ships AI features fast: per-sentence grammar breakdowns, AI transcription for videos without subtitles (40–60 videos/day on paid), full-page web translation.

Where it falls down:

• Stability is the top complaint. Store reviews repeatedly mention being logged out, subtitles failing to load, and — most damning — ads overlaying the player even for paying users.
• The learning loop is shallow. Saved words go to a flashcard list, but there's no evidence of real spaced-repetition scheduling underneath. It's a translation tool with a study feature attached, not a retention system.
• The permission footprint is wide. Full-page translation means the extension can read every page; if that bothers you, it's structural, not fixable in settings.

Pick Trancy if: you want the cheapest path to dual subtitles across many platforms and you can tolerate rough edges.

Migaku: the deep end, at a price

Migaku comes from the hardcore immersion-learning world — the Anki-and-sentence-mining tradition. It's the only one of the three with a real SRS engine and native mobile apps (iOS/Android/Web, all synced), plus courses, frequency-aware dictionaries, and subtitle generation for videos that lack them.

What holds up well:

• The study system is the product. Cards created from video carry the sentence, audio context, and word data into a proper spaced-repetition scheduler you can run on your phone.
• 11 languages are covered deeply rather than 130 shallowly: real dictionaries, real parsers (its Japanese support is a reference point), Anki compatibility.
• The community is unusually strong — a 20,000+ member Discord and a 4.7 average rating.

Where it falls down:

• There is no free tier. After the 10-day free trial it's $10/mo (or $8/mo annual, or a $499 lifetime at list price), with a 14-day money-back guarantee on paid plans — and you can't pay less for a lighter subset. The only other tier, Early Access at $15/mo, costs more and adds early access to new features.
• It's heavy. Courses, custom SRS, browser extension, mobile apps — if you just want to watch YouTube with dual subtitles, Migaku is a lot of machinery.

Pick Migaku if: you're a committed immersion learner, you'll use the mobile SRS daily, and $96–120/yr is worth a complete system to you.

The gap all three leave open

Look at the three failure modes side by side:

• Language Reactor paywalls saving — the entry point of the retention loop.
• Trancy has no real review system — saving leads nowhere.
• Migaku charges $10/mo for everything — the loop exists but behind the highest price and no free tier.

In other words: none of the three ships a free "watch → understand → save → actually review" loop with real spaced repetition. That gap is the one LingoKeep was built for — so here it is under the same lens as the other three.

LingoKeep: free spaced repetition, YouTube only

LingoKeep is ours, and the newest of the four: a Chrome extension, on the Chrome Web Store since August 2026, that adds dual subtitles, a click-any-word dictionary and one-click flashcards to YouTube, then schedules every saved card with FSRS — the open spaced-repetition algorithm Anki also offers.

What holds up well:

• Review is free. Saving words and FSRS-scheduled review work on the free plan with no time limit — the step Language Reactor puts behind Pro, and the scheduler Trancy doesn't have.
• Cards keep their context. Each card carries the sentence it came from, its translation and the moment in the video, and you review in the extension or on your phone at lingokeep.com/review once you sign in to sync.
• Pro is optional and cheap. $4.99/mo, $39/yr or $79 once removes the 100-card cap and adds Anki export — a CSV, or a one-click push into desktop Anki through the AnkiConnect add-on.

Where it falls down:

• YouTube only. No Netflix, podcasts, web pages or books. If that's where you watch, it isn't your tool.
• Four languages. Spanish, Japanese, French and German, translated into English only — against 40+ for Language Reactor and 130+ claimed for Trancy.
• Saving needs a desktop browser and captions. Like the other extensions it can't run in the YouTube mobile app, so the phone is for review only; and a video's words are clickable only when it has a caption track, human-made or auto-generated.
• The free deck stops at 100 cards. Past that, saving a new card needs Pro (or deleting an old one); everything already saved keeps coming back for review.

Pick LingoKeep if: you learn mainly from YouTube in one of its four languages and want saving plus real spaced-repetition review without paying for it — install it free. If you need Netflix or the other platforms in the table, the recommendations above stand.

FAQ

Q: Is Language Reactor still maintained? A: Yes. The "abandoned" narrative you'll see on forums doesn't match its changelog — it ships small updates roughly monthly. Big features move slowly because it's a two-person team, but it is actively maintained.

Q: What's the cheapest way to get dual subtitles on YouTube? A: Trancy's free tier, which includes dual subtitles and unlimited dictionary lookups. Language Reactor's free tier also covers dual subtitles on YouTube and Netflix. Expect ads and stability quirks on Trancy; expect a saving paywall on Language Reactor.

Q: Which extension is best for Japanese? A: Migaku has the deepest Japanese support of the three (parsing, readings, frequency data, proper SRS). If Migaku is too heavy or too expensive, that exact combination — Yomitan-style word lookup plus a built-in review system — is what LingoKeep is building for Japanese and Spanish.

Q: Do any of these work on mobile? A: Browser extensions can't run in the YouTube mobile app. Migaku ships native mobile apps for review and study. LingoKeep takes a similar split: capture happens in the desktop browser, review works on your phone as a web app.

Q: Is Language Reactor free? A: Dual subtitles and basic word lookup are free on YouTube and Netflix with no time limit, but saving vocabulary across features requires Pro at $5.95/mo or $39.95/yr. That means the free plan lets you understand what you watch without keeping any of it, which is why so many free users report watching for months and retaining little.

Q: How much does Migaku cost, and is it free? A: Migaku has no free tier — a 10-day free trial, then $10/mo, $8/mo billed annually, or a $499 one-time lifetime purchase at list price, which is often discounted (we saw it on sale for $240 on 5 October 2026). There's no cheaper plan for people who only want subtitles and lookups; the only other tier, Early Access at $15/mo, adds early access to new features.

Q: Is Migaku worth it? A: Yes if you'll use a real spaced-repetition system daily — especially for Japanese, where its parsing and dictionaries are a reference point — and you want native mobile apps, since it's the only one of the three with them. No if you mainly want dual subtitles while watching, because most of what you'd pay for is a study system and courses you won't open.

Q: Is Migaku's lifetime plan worth it? A: At its $499 list price it's roughly five years of the annual plan (at the $240 sale price we saw on 5 October 2026, about two and a half), so it only pays off on a long horizon and it's a bet on both your multi-year habit and the product's longevity. Proving the daily habit on the annual plan first is the safer order.

Q: Is there a free alternative to Language Reactor? A: Trancy's free tier is the closest like-for-like today: dual subtitles across platforms, unlimited lookups, and a 100-word save cap, with the trade-off being stability complaints and ads. The gap none of them fill is a free review system — saving plus real spaced repetition without paying — which is precisely what LingoKeep is built around.

Q: Is there a free alternative with spaced repetition? A: Among the three compared here, no: Migaku has a real spaced-repetition system but no free tier, Language Reactor's free plan can't save vocabulary, and Trancy's flashcards have no real scheduler. LingoKeep, which is ours, does it for free on YouTube — dual subtitles, a click-any-word dictionary, saving and FSRS-scheduled review in the extension or on your phone, up to 100 cards; Pro ($4.99/mo or $39/yr) lifts the cap and adds Anki export. Its limits are YouTube only and four languages (Spanish, Japanese, French, German). Anki's desktop app is also free and offers FSRS, if you're willing to make the cards yourself.

Q: Which one has real spaced repetition? A: Only Migaku among the three ships a true SRS with its own scheduler and mobile apps. Language Reactor offers PhrasePump listening drills plus Anki export rather than a full scheduler, and Trancy's flashcards show no evidence of real spaced-repetition scheduling underneath.