The notes C–E–G can sound slightly different depending on how they are tuned. Twelve-tone equal temperament and just intonation use different pitch relationships, especially for major thirds.
Comparing unrelated recordings can be difficult because timbre and volume change along with the tuning.
Browser Kitty's Tuning Compare switches between 12-tone equal temperament and 5-limit just intonation with the same notes, sound and gain. Inspect frequency and cent differences alongside what you hear, with no account or installation.
1. Set up tuning A and tuning B
Open Tuning Compare. It starts with A as 12-tone equal temperament and B as 5-limit just intonation. Keep these defaults or change the tunings.
Match the reference note and reference frequency when comparing pitch. Just intonation also needs a tonic that determines its ratios. Choose C as tonic to start with C-based chords.
Just intonation assigns pitches relative to a tonic, so the results change when you change it.
2. Start by comparing a major third
Choose Major third, set the root note, then alternate Play A and Play B to hear the same two notes under different tunings.
Listen to the character or wavering of the combined sound. A small change in the upper note may change how stable the interval feels.
The app uses the same timbre and gain for both tunings, so you can focus on pitch rather than different instruments or recording levels.
3. Try a major triad and a perfect fifth
Next choose Major triad and play C–E–G together, for example. Compare the difference you hear in a chord against the two-note interval.
You can also test a Perfect fifth. Its difference from equal temperament is much smaller than for a major third and may be hard to notice.
The built-in system is a 5-limit just-intonation preset relative to the selected tonic, not a guarantee of perfect ratios for every chord and key.
4. Read the differences in Hz and cents
The comparison table shows note frequencies in Hz and pitch offsets in cents. In 12-tone equal temperament, a semitone is 100 cents and an octave is 1,200 cents.
A major third measures 400 cents in equal temperament and about 386.3 cents at the pure 5:4 ratio. The difference is about 13.7 cents, with the 5:4 interval narrower relative to its tonic.
A perfect fifth is 700 cents in equal temperament and about 702.0 cents at the pure 3:2 ratio—a difference of roughly 2 cents. The figures remain useful even when the difference is difficult to hear.
5. Compare short phrases using the score
For a short melody, use the score editor. It starts at four measures and supports 1–16. Try the C major scale or I–IV–V–I example to begin.
Enter notes, chords and rests in 3/4 or 4/4 time with whole through sixteenth durations. Changing the input duration affects the next event you add.
Empty space in the staff does not create silence. Add an explicit rest when needed. On a phone, use the bottom Compare, Score, Tuning and Sound tabs.
6. Adjust pitches with custom tuning
Switch A or B to Custom to edit pitches by Hz, frequency ratios or cent offsets. Audition notes after small adjustments to hear the effect.
Custom tuning directly stores C4–B4; other octaves are derived using a 2:1 relationship. You cannot set every octave independently.
7. Export the tuning comparison as WAV
Save your comparison as A only, B only or A→B WAV. Both tunings use the same timbre and gain; they are not independently normalized to different peak levels.
Export is 44.1 or 48 kHz, 16-bit PCM mono WAV. MP3, MIDI, FLAC and 24-bit WAV exports are unavailable.
WAV rendering is limited to five minutes per tuning and a 256 MiB estimated memory budget. If the export is too large, shorten the score, choose one tuning or use 44.1 kHz.
8. Keep the experiment in project JSON
Project JSON stores your tunings, score, sound and WAV settings so you can reopen the experiment later. It does not include audio; export WAV separately when needed.
The app also autosaves its working state in the browser, but clearing site data may erase it. Export JSON for an independent backup.
Is the tuning data sent to a server?
Tuning Compare handles calculation, editing, playback, WAV creation and project JSON in your browser. It does not upload your score, tuning settings or generated audio for processing.
The hosted page requires an initial network request, but core processing does not need an external API or CDN. The standalone HTML can run offline in a compatible browser.
Audibility varies with speakers, headphones, browser audio and the listener. Keep the volume steady and compare repeatedly.
Tuning Compare
Compare equal temperament and just intonation by ear, inspect Hz/cents and save WAV.
References
The tuning-ratio example is supported by a music-acoustics reference; the Tuning Compare README documents app controls and limitations.
- Gijutsu-Hyoron Equal and just intonation audio examples (Japanese)
- Tuning Compare Tuning Compare: usage and limitations