What is MIME type "audio/x-mp4a-latm"?

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

audio/x-mp4a-latm signals that an audio stream uses a transport method for Advanced Audio Coding (AAC) data.
It tells media players and web browsers how to decode the audio efficiently.

Used in streaming services for smooth playback
Essential in multimedia containers for synchronized audio and video
Helpful for mobile and PC applications that play compressed audio

Files with AAC audio use this MIME type. Common file formats include MP4, M4A, 3GP, AAC, M4B, and M4P.
Using this MIME type ensures that devices know exactly how to handle the audio stream for optimal performance.
For more technical details, check the MDN Web Docs on MIME types.

Associated file extensions

.mp4, .m4a, .3gp, .aac, .m4b, .m4p

Usage Examples

HTTP Header

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


    Content-Type: audio/x-mp4a-latm

HTML

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


    <a href="file.dat" type="audio/x-mp4a-latm">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-mp4a-latm');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.mp4, .m4a, .3gp, .aac, .m4b, .m4p

FAQs

What is the audio/x-mp4a-latm MIME type used for?

This MIME type identifies AAC (Advanced Audio Coding) audio streams encapsulated using the Low-overhead Audio Transport Multiplex (LATM). It is primarily used in streaming protocols (like RTP/RTSP) and legacy mobile formats to ensure synchronization in files like .3gp and .m4a.

How does audio/x-mp4a-latm differ from audio/mp4?

audio/mp4 is the standard IANA-registered type for audio inside an MP4 container, while audio/x-mp4a-latm is a non-standard type specific to the LATM transport layer. Modern web browsers and HTML5 players generally prefer audio/mp4 or audio/aac over this experimental "x-" type.

How do I configure Apache to serve files as audio/x-mp4a-latm?

You can add the type to your .htaccess file or main configuration. Use the directive: AddType audio/x-mp4a-latm .m4a .aac .3gp. This ensures the server sends the correct headers for these specific streaming contexts.

How do I configure Nginx for audio/x-mp4a-latm?

Update your mime.types file or the types block in nginx.conf. Add the line: audio/x-mp4a-latm m4a aac;. After saving, reload Nginx to apply the changes for your audio files.

Why won't my browser play audio sent as audio/x-mp4a-latm?

Most modern browsers (Chrome, Firefox, Edge) are optimized for standard MIME types like audio/mpeg or audio/mp4. If your server sends the non-standard audio/x-mp4a-latm, the browser may trigger a download instead of playing the file; changing the Content-Type header to audio/mp4 usually fixes this.

Which file extensions are associated with this MIME type?

It is most commonly linked to .m4a (MPEG-4 Audio), .aac, and .3gp (3rd Generation Partnership Project). It may also appear with .m4b audiobooks and .m4p protected audio.

Is audio/x-mp4a-latm a security risk?

The MIME type itself is just a label, but processing malicious audio files can exploit vulnerabilities in media players or codecs. Always validate user-uploaded files and ensure your audio decoding libraries are patched against buffer overflow attacks.

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.