What is MIME type "audio/x-mpegaudio"?

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

audio/x-mpegaudio is a MIME type that denotes audio data encoded in MP3 format.
It signals to web servers, browsers, and email clients how to treat the file. It tells them that the content is compressed audio data ready for playback.

Streaming audio: Used for online radio and music streaming.
Web embedding: Supports embedding audio in websites.
Playback in media players: Allows desktop and mobile apps to decode and play the file.
File transfers: Ensures correct handling when MP3 files are sent as attachments.

Sometimes, this MIME type is used instead of the standard audio/mpeg type. It helps older systems or software recognize and work with MP3 files properly.
For additional details on the MP3 format, visit the Wikipedia entry on MP3.

Associated file extensions

.mp3

Usage Examples

HTTP Header

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


    Content-Type: audio/x-mpegaudio

HTML

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


    <a href="file.dat" type="audio/x-mpegaudio">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/x-mpegaudio');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.mp3

FAQs

What is the difference between audio/x-mpegaudio and audio/mpeg?

audio/mpeg is the official, standard MIME type for MP3 files, while audio/x-mpegaudio is a non-standard or legacy version. The x- prefix indicates it was defined experimentally or outside of IANA standards. While most modern browsers support both, it is generally better to use audio/mpeg for maximum compatibility.

Will HTML5 audio players accept audio/x-mpegaudio?

Yes, most modern browsers are lenient and will play MP3s served with audio/x-mpegaudio inside an <audio> tag. However, strict parsers or older mobile browsers might fail to recognize it as a playable format. For best results, configure your server to send the standard MIME type.

How do I configure Apache to use audio/x-mpegaudio?

If you specifically need this legacy type, you can add the AddType directive to your .htaccess file or server config. Use the line AddType audio/x-mpegaudio .mp3. Be aware that this overrides the default configuration, which usually maps .mp3 to audio/mpeg.

Why is my browser downloading the file instead of playing it?

This often occurs if the server sends a Content-Disposition: attachment header or if the browser does not recognize audio/x-mpegaudio as a streamable media type. Ensure your server uses Content-Disposition: inline and consider switching the MIME type to the standard audio/mpeg to trigger the built-in media player.

Can I use audio/x-mpegaudio for podcast RSS feeds?

Technically yes, but it is risky for broad compatibility. Major podcast directories (like Apple Podcasts) and aggregators strongly prefer or require the standard audio/mpeg. Using the x-mpegaudio variant might cause validation errors or playback failures in some podcast apps.

Is audio/x-mpegaudio a security risk?

The MIME type label itself is not dangerous, but MP3 files can theoretically contain malicious payloads targeting vulnerabilities in media players. Always validate and scan user-uploaded files, regardless of whether they are labeled as audio/x-mpegaudio or standard MP3 audio.

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.