Capture anything
Record your target language, paste text, add captions, or choose a file. Kotoru keeps the source intact so every word has context.
Language, from your real life
Understand the language you actually encounter.
Bring Kotoru a clip, passage, photo, document, or live conversation in the language you are learning. It connects useful language to what you know and gives you only what is worth practicing.
Private browser processing · No credit card · Account optional for your first three captures
Live capture · Japanese
急に天気が悪くなってきた。
天気てんきweatherNew for you
悪いわるいbadYou know this
One loop for the language around you
🎙️ Live audio▶️ Playing media📄 Text & PDFs📷 Photos🧠 Smart review
How Kotoru works
From “I heard something” to “I know it.”
See what is new
Local speech and language tools identify useful words and compare them with your personal vocabulary.
Practice less, remember more
Confirm the genuinely new items. Reviews are scheduled from your own encounters—not a generic deck.
A vocabulary map, not a word pile
Watch your language take shape.
Kotoru joins listening and reading evidence into one personal graph. See coverage, weak domains, recent encounters, and the words that matter most to you.
- Listening and reading provenance
- Personal frequency from your sources
- Spaced repetition with full context
- Portable backup and account sync
Personal coverage68%
247words mapped
31ready to learn
8due today
Local-first by design
Your source material stays yours.
The default web path transcribes and analyzes on your device. Audio is deleted after transcription. Account sync stores your learning snapshot—not your recordings, API keys, or consent history.
On-deviceDefault speech and word analysisTransparentNetwork providers are always explicitPortableExport your learning data anytimeControlledSync only after you create an account
Simple launch plans
Try the complete loop before you sign up.
Guest
3 captures
- No account required
- Full capture and word review
- Saved on this device
Free account
15 captures / month
- Cross-device snapshot sync
- Vocabulary and review stay available
- Password or email-code sign-in
Pro
Coming soon
- Higher capture limits
- Managed transcription options
- Mobile apps when released
Questions
Before your first capture
Can I try Kotoru without an account?
Yes. You can complete three captures in the browser before creating an account. A free account raises the limit and adds snapshot sync.
What languages does Kotoru support?
Kotoru is designed for multilingual learning. Japanese currently has the deepest bundled dictionary and placement support; speech and dictionary availability varies by language and platform.
Does Kotoru upload my audio?
The default browser path transcribes and analyzes on your device. Optional network providers are clearly disclosed before use.
What can I add to Kotoru?
Kotoru accepts audio, live microphone input, text, captions, photos, PDFs, and other supported documents.
Learn with Kotoru
From the blog
How to learn Japanese from Netflix without flashcard overload
A practical workflow for turning one Japanese scene into useful listening practice without mining every unfamiliar word.
Read article →Japanese listening practice with real audio: a 20-minute routine
Build Japanese listening comprehension with short recordings, careful replay, and a small personal vocabulary loop.
Read article →Why Japanese vocabulary in context is easier to remember
Learn why source sentences, listening evidence, and personal frequency make Japanese vocabulary more memorable than isolated lists.
Read article →
Turn the next thing you hear into something you know.
Three complete captures. No account. No credit card.
Try Kotoru now