What is MIME type "application/x-osu-beatmap-archive"?

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

application/x-osu-beatmap-archive designates a custom archive format. It packages game audio, images, and map data into one file.

This MIME type lets the osu! game client recognize and extract all necessary beatmap components at once. It works like a compressed container that groups related files together. Using this format improves download speed and simplifies distribution.

Centralized packaging: Bundles all beatmap assets for direct use by the game.
Efficient distribution: Reduces file size and speeds up transfers.
Automatic recognition: The osu! client detects this type to properly install beatmaps.

Files with this MIME type use an archive extension such as OSZ. For more on osu! and its beatmap archives, visit osu!.

Associated file extensions

.osz

Usage Examples

HTTP Header

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


    Content-Type: application/x-osu-beatmap-archive

HTML

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


    <a href="file.dat" type="application/x-osu-beatmap-archive">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', 'application/x-osu-beatmap-archive');
      res.end('Content here');
    }).listen(3000);

Associated file extensions

.osz

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.