JIntonation
Hear & compare tunings
Free · Designed for iPad. Not verified for macOS.
iPad
Hold a chord, switch between equal temperament and just intonation as it rings, and hear the beating smooth out. Live Hz and cents readouts make the theory audible.
JIntonation is a harmonic-table instrument for hearing the difference between tuning systems — not just reading about them.
Hold a chord, then switch between 12-tone equal temperament and just intonation with a single tap. The notes retune underneath your fingers so you can hear the beating smooth out, instantly and in context. A live readout shows each note's frequency in hertz and, in just intonation, how many cents it sits away from the equal-tempered pitch.
The notes live on a hexagonal harmonic table. Unlike a piano keyboard, the same musical interval always points the same direction: fifths run one way, major thirds another, minor thirds another. Chords become shapes you can move around the grid, and every chromatic note is always present — changing key or mode only changes what's highlighted, never what's reachable.
WHY MUSICIANS AND STUDENTS LIKE IT
• Hear tuning theory instead of memorizing it
• Compare equal temperament and just intonation on the same chord, in real time
• See exact frequencies and cents offsets as you play
• Explore intervals and chord shapes on an isomorphic layout
FEATURES
• Hexagonal harmonic-table grid with all twelve pitch classes
• Instant switching between 12-TET and fixed just intonation, even while notes are held
• Live frequency (Hz) and cents-offset readouts
• Selectable root key, mode (the seven diatonic modes), and octave
• Six synthesized tone colors, from a pure sine to a bright, harmonically rich voice
• Multitouch — play intervals and chords with up to four voices
• Touch edges and corners to sound two or three neighboring notes at once
WHO IT'S FOR
Music students and teachers exploring temperament and intonation, composers and producers curious about microtonality, and anyone who has wondered what "just intonation" actually sounds like.
JIntonation works entirely offline. There is no account, no sign-up, and no data collection.
Ratings & Reviews
- This app has not received enough ratings or reviews to display an overview.
The developer, E-String Technologies, Inc., indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Provider
- E-String Technologies, Inc.
- Size
- 2 MB
- Category
- Music
- Compatibility
Requires iPadOS 26.5 or later.
- iPad
Requires iPadOS 26.5 or later. - Mac
Requires macOS 26.5 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 26.5 or later.
- iPad
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 E-String, LLC