Web MIDI API: Enabling MIDI Device Communication in Web Applications

The Web MIDI API is a web technology that enables web developers to communicate with MIDI (Musical Instrument Digital Interface) devices directly from web applications. It allows for the integration of MIDI controllers, synthesizers, and other musical equipment into web-based music applications, opening up exciting possibilities for web-based music production and interactive experiences. In this article, we'll explore what the Web MIDI API is, its benefits, how it works, and how to use it effectively in web development.

What is the Web MIDI API?

The Web MIDI API is a JavaScript API that provides web applications with the ability to interact with MIDI devices connected to a user's computer or device. MIDI is a widely used protocol for controlling and communicating with musical instruments and equipment. With the Web MIDI API, developers can create web-based music applications, interactive music experiences, and educational tools that leverage MIDI hardware.

Benefits of the Web MIDI API

  1. Access to MIDI Hardware:

    The API enables web applications to access and utilize MIDI hardware directly, such as MIDI keyboards, synthesizers, drum controllers, and more.

  2. Musical Creativity:

    Musicians and music enthusiasts can use web applications to create music, experiment with different sounds, and develop musical compositions using their MIDI equipment within a web browser.

  3. Interactive Experiences:

    The Web MIDI API allows developers to create interactive music and multimedia experiences, enhancing user engagement and immersion.

  4. Music Education:

    Educational platforms can use the API to provide interactive music lessons, ear training exercises, and music theory tutorials with real MIDI instruments.

Using the Web MIDI API

Here's a basic example of how to use the Web MIDI API to access and interact with MIDI devices:

  .then((midiAccess) => {
    const inputs = midiAccess.inputs.values();

    for (const input of inputs) {
      input.onmidimessage = (event) => {
        const [status, data1, data2] = event.data;
        // Handle MIDI messages here
        console.log(`Received MIDI message: Status=${status}, Data1=${data1}, Data2=${data2}`);
  .catch((error) => {
    console.error('MIDI access request failed:', error);

In this example:

  • We use navigator.requestMIDIAccess() to request access to MIDI devices.
  • Once access is granted, we retrieve MIDI input devices and set up event listeners to handle incoming MIDI messages.
  • We log MIDI message data to the console, but developers can use this data to create various interactive music experiences.

By utilizing the Web MIDI API, web developers can harness the power of MIDI devices to create interactive and innovative music applications and experiences that run directly within web browsers, opening up new opportunities for musical creativity and education.

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