Kitsumi

Kitsumi 🦊

Learn Japanese from the anime, YouTube and shows you already watch.

Native subtitles with a dictionary under your cursor. A word goes by that you don't know - hover it: reading, meaning, grammar, in about a second. Then keep watching. No pausing, no tab switching, no copy-paste into a dictionary.

Watching foreign video with English subtitles never really worked - you read English, you learn English. What you needed was native subtitles with the meaning one hover away. Open YouTube and it just works: pick your track and go. Watching anime? Find subtitles without leaving the page. Japanese is the main focus; 45+ other languages come along for the ride.

Free. No account. No subscription. No telemetry. Built and tested in Firefox first.

🌱 MICRO-DOSE LEARNING

A hover gives you two seconds with one word, then you're straight back to the story. The same word turns up two scenes later, next episode, next week - one hover away every time.
• Hundreds of tiny, well-spaced encounters with words you care about, without turning the episode into homework.

🔍 HOVER A WORD, KNOW A WORD

• Interactive subtitles - readings with furigana, definitions, part of speech, JLPT level and frequency, over anime sites, YouTube, Netflix, Crunchyroll and most HTML5 players.

• Two readings of every line - the lower half of a word gives the whole word (ひび割れた), the upper half its pieces (ひび割れ | た). Japanese has no spaces, so when one guess is wrong, the other gives you a way out.

• Hover the pieces - a word shown through its parts (曇りなく = 曇り + なく) explains each part, with plain grammar notes for endings like なく, ず, ながら, なきゃ.

• Explain this line - a small star on the subtitle opens the line's translation and every word in it.

• A calm popup - pinned above the line, gliding between words instead of jumping.

• Smooth pause - pause on hover with an instant stop or a Fade, Tape stop, Soft or Vinyl wind-down. Volume and speed always come back exactly.

🎬 SUBTITLES, YOURS, ON TOP OF ANYTHING

• Load your own .srt, .vtt or .ass subtitles, restyle and reposition them, then save the loaded track (including YouTube captions) as .srt or plain text.

• Search Jimaku, OpenSubtitles and SubDL without leaving the video. Each uses a free key of your own.

• Precision sync from ±10 ms to ±1000 ms, saved per show. Auto-next episode keeps your setup.

🧠 STUDY AND MINING

• Study Mode - turns the current line into word cards with furigana. Particles get their own grammar cards; words you know shrink to tiny chips.

• Anki mining - word, reading, definition, sentence, screenshot, audio and clip.

• Comprehension target - see how much of an episode you already know.

• Stats, 36 ranks and 200+ achievements - earned from what you were doing anyway.

📚 DICTIONARIES

Japanese gets the full stack: Jitendex, JMdict in eight languages, JMnedict, KANJIDIC with JLPT levels and JMdict example sentences - sixteen dictionaries, one click each.

Every other language runs on Yomitan-format dictionaries (.zip / .json) or plain .tsv word lists. Once installed, lookups work with no internet at all.

Advanced scanning splits Japanese and Chinese lines into real dictionary words from a free word pack you download once.

46 dictionary languages. Interface in 20.

🖱 BEYOND THE PLAYER

Articles Reader brings the same hover lookup to any web page.

OCR pulls text out of images, video frames and manga pages, recognised on your device.

Optional AI (Groq, WaveSpeed) sleeps until you paste your own key.

🪶 LIGHT ON PURPOSE

Nothing runs while nothing is happening - no background polling, no leftover timers.

Super optimized mode is available for older laptops.

🧠 HONEST NOTE

It won't learn the language for you.

Hovering is recognition; what builds memory is guessing before you look and using the word yourself. Ranks and XP measure activity, not ability.

🔒 PRIVACY

Your words, progress and settings stay in your browser. No account, no server, no analytics, nothing that reaches me.

Network requests happen only when a feature needs one - subtitle search, downloading a dictionary, font or word pack, an online dictionary lookup, pronunciation audio, OCR language data, or an AI feature using your own key.

Online lookups and AI are off until you switch them on. Explaining a line sends it to MyMemory only if MyMemory is one of your online dictionaries, and to DeepL only if you entered your own DeepL API key. An email you enter for MyMemory's higher limit goes only to MyMemory.

Full details:
https://kitsumi.org/privacy

Kitsumi needs broad site access because subtitles are drawn over players it can't know about in advance, including embedded frames.

Want it tighter? Allow it only on the sites you use:
Add-ons → Kitsumi → Permissions

Everything still works.

🦊 Unknown word → hover → understood → back to the episode.

https://kitsumi.org
Discord: https://discord.gg/UpmNHxT7PF