How to check every octave on a MIDI keyboard
Check each octave of a MIDI keyboard in your browser, compare note numbers across the range, and find out whether a mismatch comes from the controller or app.
You press a key in each octave, but the notes sound too high, too low, or the same as notes elsewhere on the keyboard. The cause could be an octave shift on the controller, a setting in your music app, or simply a difference in how software names notes.
Use the MIDI Test to see which notes the keyboard actually sends. Comparing the note numbers across the keys helps you separate a real mismatch from a different octave-labeling convention.
Check the notes from each octave
- Connect your MIDI keyboard to the computer, then open the MIDI Test. Safari does not support this test, so use a different browser if you are in Safari.
- If the browser asks for permission to access MIDI devices, allow it. Play a key and check that the test shows incoming key activity or a MIDI message.
- Start at the lowest octave. Press one key at a time, then note the displayed note or MIDI note number. If you cannot see a number for a key, use the message details shown by the test.
- Press the same note position in the next octave. For example, compare the C key in one octave with the C key directly above it. Its MIDI note number should be 12 higher.
- Repeat the comparison up the keyboard, including the highest octave. Check the other keys too if you need to confirm that every note in each octave is present and in order.
A MIDI note number increases by 1 for each semitone, the distance from one key to the next. An octave is 12 semitones, so matching keys in adjacent octaves should differ by 12. For instance, if one C sends note number 60, the C an octave above should send 72.
What the result means
Matching keys are 12 numbers apart
The keyboard is sending the expected octave spacing. If the notes still sound wrong in your music app, check that app's instrument, track, or MIDI input settings. The controller may be working correctly while the app shifts the notes.
Every key is shifted by the same amount
If the same physical keys consistently send notes higher or lower than expected, an octave or transpose setting may be active. Transpose shifts notes by semitones; octave shift moves them by 12 semitones at a time. Check the keyboard's display and controls before changing a setting in the music app.
The octave labels look different, but the numbers match
Programs do not all use the same names for MIDI octaves. A note may appear as C3 in one program and C4 in another, even though both refer to MIDI note number 60. Compare note numbers or the interval between matching keys, not the octave label alone.
A key produces no message, or the pattern skips
The browser is not receiving a note from that key, or the keyboard is sending an unexpected note. Repeat the press once and check nearby keys. If the same key is consistently missing, continue with the fixes below. If no keys appear at all, see how to test a MIDI keyboard that is not sending notes.
How to fix an octave mismatch
- Check the octave buttons. Many controllers have buttons or switches that shift the keyboard up or down by one or more octaves. Return the shift to its neutral setting, then test the same keys again.
- Check transpose controls. Look for a transpose setting on the keyboard. Set it to zero or its default position. A transpose change of 12 semitones has the same pitch effect as an octave shift.
- Reconnect the keyboard. Disconnect and reconnect its USB cable, or reconnect its wireless MIDI connection. Reload the test and allow MIDI access again if the browser asks.
- Test in a supported browser. If no messages appear, try Chrome or Edge on the computer. MIDI Test does not work in Safari. If the keyboard appears in the test but not in your music program, check that program's selected MIDI input and track settings.
- Check the controller's configuration. Some keyboards save octave, transpose, split, or zone settings in a preset. Restore a neutral preset or consult the controller's instructions for its reset procedure, then repeat the octave comparison.
Windows 11 and macOS do not have one shared system setting that corrects octave shifts for every MIDI keyboard. Check the keyboard itself and the music app that is receiving the notes. The browser's MIDI permission prompt controls whether the test can see the device, not which pitches the keyboard sends.
When the keyboard may have a fault
If one key repeatedly sends the wrong note or sends nothing, test it again after reconnecting the keyboard and resetting its octave or transpose settings. Try another USB port or cable if the connection is wired. If the same key still fails in the browser test and in another MIDI app, the key or controller may need repair. Contact the manufacturer if it is under warranty, or have it inspected before paying for a repair.
Why note names can be confusing
MIDI messages identify notes with numbers. Note number 60 is commonly called middle C, but software makers disagree about whether to label it C3, C4, or another octave name. The number and the 12-step difference between octaves are more dependable than the label. If your keyboard sends the expected sequence and each octave is 12 numbers apart, a different name on screen does not by itself mean anything is wrong.
