Migaku vs Octopus Lang: An honest comparison

Credit where it’s due: Migaku has done more than almost anyone to make the immersion method approachable. It grew out of the immersion-learning community, spent years refining the approach on its blog, and turned a pile of fiddly browser add-ons into something polished enough that a normal person can sit down and use it. If you learn by watching Netflix and YouTube in your target language, Migaku is the most finished tool in that lane.

People keep asking how Octopus compares. The two share a philosophy — learn from real, native content — but take almost opposite routes to get there. Here’s the honest version, including the parts where Migaku is the better choice.

The short version

Migaku is a browser extension, plus mobile apps, that layers learning tools onto streaming. It works inside Netflix, YouTube, Disney+, and others: click a word in the subtitles for a definition, make a flashcard with the audio and screenshot in one click, and follow beginner courses to get off the ground. Monthly subscription, or a lifetime license.

Octopus is a native desktop app that turns your own files into study material. Drop in a film, a YouTube link, or an audiobook and it transcribes locally with Whisper. Vocabulary is tracked by lemma, your library never leaves your machine, and you pay once. No mobile app yet, no streaming-platform integration.

The rest of this post is for anyone still weighing the trade-offs.

Where Migaku is better

Streaming integration

Migaku lives inside the streaming services. Turn it on, open a show on Netflix or a video on YouTube, and the subtitles become interactive in place — nothing to download, nothing to transcribe. You’re studying the thing you were already watching. Octopus works with files and YouTube links, not inside the streaming apps. If your study diet is mostly Netflix, that’s a real difference.

Mobile

Migaku has iOS and Android apps. A lot of immersion happens on a phone on the train. Octopus is desktop only; mobile is on the roadmap and not here yet.

Beginner courses

Migaku ships structured courses for Japanese, Mandarin, Korean, and English that take you to roughly 1,500 words and the grammar you need before native content stops feeling like a wall. Octopus assumes you already have content you can mostly follow, and brings no courses of its own.

Community and method

Years of methodology writing and an active Discord. If you want a community to learn the immersion approach alongside, Migaku has one. Octopus is a tool, not a movement.

Where Octopus is better

Your own files, not just streaming

This is the core split. Migaku’s reach stops where the streaming platforms stop cooperating, and it leans on subtitles that already exist. Octopus runs Whisper on your machine and transcribes anything you actually have — the film on your drive, the documentary with no subtitle file, the YouTube lecture whose auto-captions are too rough to study, the audiobook. A show with no subtitles at all becomes a clickable, mineable transcript in a few minutes. Details are in our Whisper post.

Lemma-based vocabulary

Migaku handles inflection better than LingQ, but it still tracks per form rather than collapsing everything to the dictionary word. In Octopus, mark 食べる — or hablar, or parler — known once and every conjugation counts as known, across every film and book, not just the one in front of you. For a heavily inflected language that’s the difference between a known-word count that means something and one inflated three to five times over.

Offline and private

Octopus reads your files locally. No streaming session, no extension watching what you watch, no upload. Your library, vocabulary, and progress stay on your computer, and you can study on a plane. Migaku is partially offline at best and, by design, sits between you and the streaming services.

Price

Migaku is roughly $10/month, or $499 for a lifetime license. Octopus is $49.99 once. Migaku’s lifetime price is honest for an ongoing service with mobile sync and streaming support to maintain — but if what you want is a tool that runs on your own computer, paying once and an order of magnitude less is hard to argue with.

Bring your own dictionaries

Octopus reads FreeDict and WikDict, and for Japanese it imports any Yomitan-format dictionary and frequency list — the same files you already trust. You pick what’s actually good for your language pair instead of taking whatever the platform bundled.

Reading real books

Octopus has a native two-page reader for EPUB that fills the window like a real book — no browser chrome, instant local lookups, pages turning on the keyboard. Migaku is built around video in the browser; for long reading sessions, a native reader is a different experience.

Roughly even

Anki export with audio

Both build flashcards with the audio clip and a screenshot from the source moment, in roughly one click. If you sentence-mine seriously, both do the job well.

Click-to-define

Both give you an instant definition when you click a word while watching or reading. The interaction is fine in both.

Japanese

Both are strong here. Migaku has deep Japanese roots; Octopus tokenizes with UniDic, puts furigana over the kanji, draws pitch-accent graphs, and ships JMdict and KANJIDIC2. If Japanese is your language you’ll be well served either way — the deciding factor is streaming-versus-your-own-files, not the Japanese support itself.

Who picks which

Pick Migaku if: you study mostly through Netflix, YouTube, and other streaming services; you want to learn on your phone; you’re early enough to want structured beginner courses; you like having a community and a documented method around you.

Pick Octopus if: you want to study films, videos, and audiobooks you own — including ones with no subtitles; you’re tired of marking every conjugation as a separate word; you want your library to stay on your machine and work offline; you’d rather pay once than subscribe; you read books seriously and want a real reader; you study at a desktop.

Pick both if: you want Migaku inside the streaming apps and on your phone, and Octopus for the files you own and the long reading sessions.