Yokuyo 抑揚 — See the melody of Japanese

Getting started

Download & run the installer. Windows may warn it's from an “unknown publisher” — click More info → Run anyway. (Yokuyo isn't code-signed yet; the installer and source are open to inspect.)
Let it set up the speech engine. Yokuyo uses VOICEVOX (free) for audio and pitch. It's detected and started for you automatically — if it isn't installed, Yokuyo opens the download page and picks it up once installed, no restart needed.
Analyze. Type or paste a Japanese sentence and press Analyze to see its pitch contour, hear it, and explore the rules.
Optional — add the browser extension. Use Yokuyo while you read: hold Shift and hover Japanese text on any page. It works while the desktop app is running.

Windows 10 / 11 · No audio? Make sure VOICEVOX is running (Yokuyo starts it for you).

What it does

Sentence-level pitch contour

See the continuous F0 curve for any Japanese sentence — how accent phrases connect and where downstep happens.

OJAD-style notation

Clear high/low step marks above the kana, with the original text aligned beneath each phrase.

Listen & shadow

Hear the sentence with natural speech synthesis, adjust speed, and loop phrases for practice.

Pitch accent rules

Tap any word to see the pitch accent rules for its word class — nouns, verbs, adjectives, particles, and more.

In your browser

Companion browser extension

Hold Shift and hover over Japanese text on any web page to see its pitch contour, right alongside your popup dictionary. The extension works together with the desktop app running on your computer.

Get the Chrome extension