How to Completely Disable the ‘Web MIDI API’ via Group Policy in Microsoft Edge

Microsoft Edge includes native support for the Web MIDI (Musical Instrument Digital Interface) API, a browser capability that allows web applications to interface directly with connected MIDI hardware devices such as synthesizers, drum machines, and digital audio workstations (DAWs). While highly beneficial for browser-based music production and audio engineering tools, the Web MIDI API represents a niche attack vector and an operational security (OPSEC) liability on provisioned corporate workstations or secure terminals where external peripheral interfacing must be strictly governed. Malicious or compromised websites could attempt to probe for connected MIDI hardware, potentially exploiting firmware vulnerabilities in the connected devices or fingerprinting the terminal based on its connected peripheral profile.

This guide explains how to completely disable the Web MIDI API via Group Policy in Microsoft Edge, enforcing a strict, system-wide block that prevents any website from enumerating, accessing, or interacting with connected MIDI hardware devices.

Disable the Web MIDI API via Group Policy

To enforce a strict configuration that explicitly strips the browser of its ability to broker connections to MIDI hardware and overrides any user-defined site permissions, we must deploy an administrative template.

1. Log into Windows with an Administrator account.
2. Press the Windows Key + R to open the Run dialogue box.
3. Type gpedit.msc and press Enter to launch the Local Group Policy Editor.
4. In the left-hand navigation pane, strictly follow this exact path:

   Computer Configuration > Administrative Templates > Microsoft Edge > Content settings

5. In the right-hand pane, locate the policy named Default Web MIDI API setting (internally known as DefaultWebMidiSetting).
6. Double-click the policy to open its configuration window.
7. Select the radio button next to Enabled.
8. Under the Options section, locate the dropdown menu labelled “Default Web MIDI API setting”.
9. Explicitly select Block the Web MIDI API (Option 2). (By setting this to Block, we instruct the Edge rendering engine to automatically and silently reject any site requests to use the navigator.requestMIDIAccess() method, preventing all MIDI peripheral interaction).
10. Click Apply, then click OK.

Verify the Configuration Lockdown

Group Policy changes modifying Edge hardware APIs require the browser to update its local policy state.

Close all active instances of Microsoft Edge. To force the policy update immediately across the OS, open Command Prompt as Administrator and run gpupdate /force. To verify the restriction is actively enforced, launch Microsoft Edge and navigate to edge://policy. Search for DefaultWebMidiSetting and confirm its value is set to 2 (Block). Furthermore, navigate to a Web MIDI testing site (such as a browser-based synthesizer). Attempting to connect a MIDI controller will fail silently or display an API access error, confirming that the browser’s MIDI interfacing pipeline is completely severed and secured against peripheral probing.