What Browser and Device Do I Need to Use MIDI Recorder?

Updated

MIDI Recorder needs three things to work: JavaScript enabled, a browser with Web MIDI access, and a MIDI input device that your computer recognizes. Chrome is the safest choice. If you use another browser, you may need the Jazz-Soft Web MIDI API extension before the app can see your keyboard.

The three requirements

Requirement Why it matters What happens if it's missing
JavaScript enabled The app itself is a script-driven page You see "This app requires JavaScript" instead of the recorder
Browser with Web MIDI access The page reads MIDI data through the Web MIDI API You see "This browser doesn't support MIDI access"
A connected MIDI input device The app records what the device sends You see "No MIDI devices detected"

All three must be satisfied at the same time. A supported browser with no keyboard plugged in still won't record anything.

Which browsers work

Chrome is the browser the app points to directly. If you're on a different browser and the app reports no MIDI support, the suggested fix is the Jazz-Soft Web MIDI API extension, which adds MIDI access to browsers that don't expose it natively.

So your practical options are:

  • Chrome — use it as-is, no extension needed.
  • Other browsers — install the Jazz-Soft Web MIDI API extension, then reload the page.

If you'd rather not install an extension, switching to Chrome is the simpler path.

What counts as a MIDI device

The app lists whatever MIDI inputs your system reports under "MIDI devices." That's typically a USB MIDI keyboard, but any device that presents itself as a MIDI input to your computer can appear there. The page loads this list dynamically, so it briefly shows "Loading..." before the devices appear.

The app's own guidance for a device that isn't showing up:

  1. Make sure it's plugged into your computer and turned on.
  2. Refresh the page.
  3. Unplug it and plug it back in.
  4. Restart your computer.

These steps address the common case where the device is physically connected but the browser hasn't picked it up.

Quick check before you start

Open the page and look at the MIDI devices list:

  • Your device is listed — you're ready to record.
  • "No MIDI devices detected" — the browser has MIDI access but sees no input; work through the plug-in/turn-on/refresh steps above.
  • "This browser doesn't support MIDI access" — the problem is the browser, not the device; switch to Chrome or add the extension.

Once a device appears, plug in your keyboard and play — the app records the notes as you go, and you can export them with "Save MIDI File."