What is MIME type "audio/midi"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

audio/midi is a MIME type for files that store musical instructions—not recorded sound.
It carries data that directs synthesizers to play notes, set tempos, and choose instruments. This data is like a digital score that instructs how music should sound when played.

Key uses and facts:

Digital Composition: The format is common in music production and sequencing software.
Interactive Media: Video games and multimedia apps use it for adaptive and dynamic soundtracks.
Karaoke Systems: Some files include lyrics and timing data, enhancing the karaoke experience.

Files of this MIME type often come with extensions such as MIDI, MID, KAR, and RMI.
These files are lightweight and allow for easy editing of musical data. They enable devices and software to generate sound in real time based on the provided instructions.

For additional technical details, check the IANA media types registry or the MIDI official website.

Associated file extensions

.midi, .mid, .kar, .rmi

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: audio/midi

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="audio/midi">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');    
    
    http.createServer((req, res) => {    
      res.setHeader('Content-Type', 'audio/midi');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.midi, .mid, .kar, .rmi

FAQs

How does audio/midi differ from formats like MP3 or WAV?

Unlike MP3 or WAV files which store actual recorded audio waveforms, audio/midi files store musical instructions (notes, pitch, velocity) that tell a synthesizer how to play the music. This makes MIDI files significantly smaller, but the audio quality depends entirely on the playback device's sound bank.

Do web browsers natively support audio/midi playback?

Most modern browsers do not support playing audio/midi files directly via the HTML5 <audio> tag. To play MIDI on a webpage, developers typically use JavaScript libraries (like MIDI.js) or the Web MIDI API to synthesize the sound within the browser.

How do I configure Apache or Nginx to serve MIDI files?

For Apache, add AddType audio/midi .mid .midi .kar to your .htaccess or configuration file. For Nginx, ensure your mime.types file includes the line audio/midi mid midi kar; to prevent browsers from interpreting the files as plain text.

What is the relationship between the .kar extension and audio/midi?

The KAR extension stands for Karaoke. These are standard MIDI files that contain synchronized lyrics in specific text tracks. They utilize the audio/midi MIME type and can be played by most standard MIDI players, though specialized software is required to display the lyrics.

Is the correct MIME type audio/midi or audio/x-midi?

The standard, IANA-registered MIME type is audio/midi. While you may encounter audio/x-midi or audio/mid in older legacy systems or incorrect server configurations, you should always use audio/midi for maximum compatibility.

Why do I hear no sound when playing an audio/midi file?

Because MIDI files contain instructions rather than sound, your computer must have a configured SoundFont or MIDI mapper to generate the audio. If your system volume is up but the file is silent, check your media player's settings to ensure a valid software synthesizer is selected for MIDI output.

Are audio/midi files safe to download?

Generally, yes; MIDI files are data streams of musical notes, not executable programs. However, security vulnerabilities in specific media players that parse malformed headers have existed in the past, so it is important to keep your playback software up to date.

When should I use audio/midi instead of other audio formats?

Use audio/midi when file size is a critical constraint or when the music needs to be interactive (such as in web games). A MID file might be only 10KB where an equivalent MP3 would be 3MB, making it ideal for low-bandwidth environments.

General FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.