What is MIME type "audio/matroska"?

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

The MIME type audio/matroska is an open container format built on the Matroska framework that stores audio-only content.
It supports detailed metadata, multiple audio streams, chapters, and embedded images. This means it can handle high-quality recordings and advanced playback features.
It is used in environments that need robust audio data management and precise information tracking.

High-quality audio preservation with support for multiple tracks
Enhanced metadata integration for chapters and cover art
Flexibility for streaming and archiving audio content

Files associated with this MIME type include the Matroska family such as MKV, MKS, MKA, and MK3D.
More technical details and specifications are available at the Matroska official site.

Associated file extensions

.mkv, .mks, .mka, .mk3d

Usage Examples

HTTP Header

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


    Content-Type: audio/matroska

HTML

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


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

Associated file extensions

.mkv, .mks, .mka, .mk3d

FAQs

Which file extension is primarily associated with audio/matroska?

The primary file extension for this MIME type is .mka (Matroska Audio). While the Matroska container family includes .mkv for video and .mks for subtitles, audio/matroska is specifically used for files containing only audio streams.

How do I configure Apache to serve .mka files correctly?

To ensure browsers recognize the file as audio, add the MIME type definition to your .htaccess file or server config. Use the directive: AddType audio/matroska .mka. This prevents the server from sending it as a generic application/octet-stream.

Is audio/matroska supported in HTML5 web browsers?

Support is mixed. Modern browsers like Chrome, Firefox, and Edge generally handle Matroska containers (often due to WebM compatibility), allowing playback via the HTML5 <audio> tag. However, Safari (macOS/iOS) often lacks native support, so a fallback to MP3 or AAC is recommended for broad compatibility.

What is the difference between audio/matroska and video/matroska?

audio/matroska implies the container holds audio-only content (typically .mka), making it suitable for music albums or audiobooks. video/matroska (or video/x-matroska) is used for files that include video streams, commonly associated with the .mkv extension.

Can I store multiple languages in an audio/matroska file?

Yes, one of the strongest features of the Matroska format is its support for multiple audio tracks within a single file. This is ideal for archiving music with instrumental versions or audiobooks with multiple language narrations in one .mka file.

How do I add audio/matroska support to Nginx?

You should edit your mime.types file, typically located in /etc/nginx/. Add the line audio/matroska mka; inside the types block. Afterward, reload the server using sudo nginx -s reload to apply the configuration.

Why won't my default media player open an .mka file?

Many default operating system players (like Windows Media Player or older QuickTime versions) do not support the Matroska container natively. To play these files, use a robust third-party player like VLC Media Player or install a codec pack (such as K-Lite).

Is audio/matroska a compression codec like MP3?

No, Matroska is a container format, not a codec. An .mka file acts as a wrapper that can contain audio compressed with various codecs, such as MP3, AAC, Vorbis, or lossless FLAC. It manages how that data is stored and retrieved alongside metadata.

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.