Online Xylophone Tuner
Pick your instrument, check every bar against its true pitch, record what you play and hear it back — with the loudness of each strike kept, dual and quad hits replayed as chords, and a detector that names whether you have a xylophone, marimba or glockenspiel.
You can't tune a xylophone the way you tune a guitar — there is no peg to turn. A bar's pitch is locked into its length and the curve carved out of its underside. So a xylophone "tuner" does a different job: it tells you which bars have drifted from where they should be, and helps you play, capture and listen back to what the instrument is actually doing.
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The one fact that separates a xylophone from a marimba
Strike a bar and you don't hear one frequency — you hear the fundamental plus a set of overtones. A maker tunes a bar by carving a scallop out of its underside, which shifts where the strongest overtone lands. That single choice is the line between the two instruments.
A xylophone bar is "quint-tuned": its strong overtone is set a twelfth above the note — an octave plus a fifth, exactly three times the fundamental frequency. Strike a C on a xylophone and the prominent overtone is the G nearly two octaves up. A marimba bar is "octave-tuned": its strong overtone sits two octaves up, four times the fundamental — strike a C and you hear a C ringing above it. That is why a marimba sounds round and warm and a xylophone sounds bright and hard: the marimba's overtone reinforces the note like a string or a wind instrument, while the xylophone's hollow twelfth gives it that clipped, clattering brilliance closer to a clarinet.
This is exactly what the Sound-Type Detector listens for. Strike one bar cleanly in Tune mode and it measures the overtone ratio: land near ×3 and it calls a xylophone, near ×4 a marimba. The same physics, read backwards from the sound.
How it hears two — or four — bars at once
Pulling several simultaneous notes out of a raw microphone signal is one of the genuinely hard problems in audio. This tool sidesteps it with a constraint: once you've chosen a configuration, it already knows every pitch that instrument can make. So instead of asking "what notes are these?", it asks the far easier question "which of these known bars just rang?"
At each strike it measures the energy sitting at every configured bar's frequency, ranks them, and keeps the group that crossed the threshold together — up to four. One bar over threshold is a single hit; two is a dual; four is a quad. The loudness of the strike is read from the signal's peak level at that instant and stored with the note, so when you replay, a soft tap stays soft and a hard one stays hard.
A practical note: simultaneous detection is best-effort and works most cleanly with a quiet room, a decent mic distance (about 15–30 cm), and an honest pick of the configuration you actually own. Picking "Concert 4-oct" when you're playing a soprano Orff will make it hunt for bars that aren't there.
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The standard configurations, and which one you have
"Xylophone" covers a family of instruments with very different ranges. Pick the one that matches yours in the tuner — it sets the bar layout, the targets, and the default replay tone.
The small classroom xylophone most people have actually held. Diatonic (white-note) bars in C major, removable for the Orff teaching method. Rosewood or synthetic bars, short dry tone.
The alto sits an octave below the soprano. Same diatonic C-major layout, longer bars, warmer tone. Soprano + alto + bass make up a standard Orff classroom set.
The default professional instrument. Fully chromatic across three and a half octaves, F4 to C8, laid out like a piano keyboard. Bright, penetrating, very short sustain.
A four-octave xylophone adds a low half-octave down to C4 for repertoire that needs it. Otherwise identical in tone and tuning to the 3.5-octave standard.
Not wood at all — steel or aluminium bars, two and a half octaves, sounding two octaves higher than written. The bright, bell-like "Sugar Plum Fairy" sound, with a long shimmering ring.
The xylophone's deep cousin. Wider rosewood bars octave-tuned for a rounder, longer, warmer tone. Included here so the detector can show you the overtone difference directly.
Using the tuner
Checking a bar. In Tune mode, strike one bar on its own. The big readout names the nearest bar and shows how many cents sharp or flat it is. Bars drift flat over years as the wood dries; if a bar reads consistently 10–20 cents low against a quiet, single, centred strike, it's a candidate for a professional re-tune — there is nothing you can adjust at home without removing material.
Recording. Switch to Record mode, tap Record, play a phrase, then Stop and Replay. Each strike comes back at the loudness you hit it, and anything you struck together replays as a chord. Use the timbre buttons to hear the same phrase back as a marimba or glockenspiel.
No instrument handy? Tap the bars in the diagram directly — they play the true pitch in your chosen timbre, no microphone needed. It doubles as a reference for tuning by ear.
Frequently asked
+Can you actually tune a xylophone yourself?
Not with any control on the instrument — the pitch is built into the bar's length and undercut. Lowering a bar means shaving its underside; raising it means shortening the ends. Both are skilled jobs done with the bar off the frame and a strobe tuner. This page tells you which bars have drifted so you know what needs that attention.
+What does "×3 overtone" actually mean?
It means the strong overtone you hear above a struck note is three times the note's frequency — a twelfth higher in pitch. That is the defining feature of a xylophone bar. A marimba's strong overtone is four times the fundamental, two octaves up, which is why it sounds warmer.
+Why does the detector sometimes say marimba on my xylophone?
Overtone balance shifts with mallet hardness and where you strike. A soft mallet near the bar's end weakens the overtone and can confuse the reading. Strike near the centre with a medium mallet, one bar at a time, in a quiet room, and let it take a few samples before trusting it.
+Does the recorder capture timing and dynamics?
Yes. Every strike stores its time and its loudness, and groups of bars hit together are kept as a single chord event, so the replay reproduces your rhythm, your dynamics, and your chords — just re-synthesised in whichever timbre you select.
+Is it free, and does it work on a phone?
Completely free, no sign-up, and it runs in any modern mobile browser. On a phone, hold the device 15–30 cm from the bars. Microphone access needs the page to be on HTTPS.
+Is my audio sent anywhere?
No. Everything happens in your browser using the Web Audio API. No audio is uploaded, recorded to a server, or stored. Closing the tab ends the session.
More tuners & music tools
Sources & technical references
- Yamaha Music, "What's the Difference Between Marimba and Xylophone?" — confirms xylophones use quint tuning (fundamental + 3rd overtone) and marimbas use octave tuning (fundamental + 4th overtone).
- Jim Woodhouse, Euphonics: the Science of Musical Instruments, §3.3 "Marimbas and xylophones" — undercutting the bar to set the overtone ratio to 3:1 or 4:1, and the role of tuned resonators.
- Heartland Marimba, "Marimba Construction & Tuning" — the marimba bar tuned to two octaves (and a higher partial) above the fundamental as the principal intonation difference from the xylophone.
- Thomas D. Rossing, Science of Percussion Instruments (World Scientific, 2000) — mode shapes and tuned partials of bar percussion (xylophone 1:3:6, marimba 1:4:10).
- Alain de Cheveigné & Hideki Kawahara, "YIN, a fundamental frequency estimator for speech and music," JASA 111(4), 2002 — the pitch-estimation background; this tool uses constrained spectral matching against the known bar set rather than YIN, because the targets are known and the signal is polyphonic.
- The constrained-detection approach (score the known bar frequencies, keep the set that crossed threshold together) is an original adaptation for this page — it trades general transcription for reliable multi-hit detection within a chosen configuration.
A xylophone can't be tuned by turning anything — but it can still be listened to closely. That's the whole job.