Request Midi Access On Firefox Does Not Work

This is a known issue with Firefox's MIDI implementation. Unlike Chrome, which allows requesting MIDI access even if no devices are currently connected, Firefox denies access outright if no MIDI devices are detected at the time of the request.

Solutions

1. Restart Firefox

   • If you connected the MIDI device after starting Firefox, restart the browser and try again.

2. Check Firefox Permissions

   • Open about:config in a new tab.
   • Search for dom.webmidi.enabled.
   • Ensure it is set to true. If not, double-click to enable it.
   • Search for privacy.resistFingerprinting (if enabled, it can block MIDI access).
   • Set privacy.resistFingerprinting to false.

3. Verify Device Detection

   • Check if your OS detects the MIDI device.
   • On macOS: Open Audio MIDI Setup > MIDI Studio and ensure your device is listed.
   • On Windows: Check Device Manager under "Sound, video and game controllers."

4. Force Firefox to Recognize the Device

   • Connect your MIDI device before starting Firefox.
   • Restart the browser with the device already connected.

5. Use Chrome or Edge

   • If Firefox's handling of MIDI is problematic, you might consider using a Chromium-based browser for MIDI-related tasks.

(ChatGPT Feb. 2025)