What is MIME type "application/metalink4+xml"?

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

The MIME type application/metalink4+xml signals an XML file that follows the Metalink version 4 specification. It packages multiple download options and extra details to help manage file transfers.
A file with the designated format appears as a META4 document. The XML structure holds data such as mirror addresses, file size, and verifications like hash codes. These features support reliable, efficient, and resumable downloads with many download managers.

XML-Based: Uses a structured markup that is easy for programs to read and process.
Multiple Sources: Lists several download URLs to ensure availability and speed.
Integrity Checks: Contains cryptographic hashes to verify file authenticity.
Optimized Downloading: Enables splitting downloads into parts and resuming disrupted transfers.

Learn more about Metalink and its benefits at this resource.

Associated file extensions

.meta4

Usage Examples

HTTP Header

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


    Content-Type: application/metalink4+xml

HTML

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


    <a href="file.dat" type="application/metalink4+xml">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/metalink4+xml');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.meta4

FAQs

What is the purpose of the application/metalink4+xml MIME type?

This MIME type identifies a Metalink version 4 document, usually saved with a .meta4 extension. It contains XML data listing multiple download mirrors, peer-to-peer links, and cryptographic hashes (like SHA-256) to ensure file integrity and allow for faster, segmented downloads.

How do I configure Apache to serve .meta4 files correctly?

To ensure Apache serves the correct content type, add the following line to your .htaccess file or main configuration: AddType application/metalink4+xml .meta4. This prevents browsers from misinterpreting the file as generic text or XML.

How do I set up Nginx for Metalink 4 files?

In your Nginx configuration (often inside nginx.conf or a specific mime.types file), add the directive: application/metalink4+xml meta4; inside the types block. Reload the server to apply the changes.

Why does my browser display code instead of downloading the file?

Since application/metalink4+xml is XML-based, web browsers often display the raw XML tree by default. To utilize the download features, you need a specialized download manager (like aria2 or Free Download Manager) or a browser extension that supports the Metalink protocol.

What is the difference between application/metalink4+xml and application/metalink+xml?

application/metalink4+xml corresponds to Metalink 4.0 (RFC 5854) and typically uses the .meta4 extension. The older application/metalink+xml is for Metalink 3.0, which usually uses the .metalink extension. Version 4 is a streamlined, standard-compliant XML format.

Can I edit a .meta4 file manually?

Yes, because the file structure is standard XML text. You can open and edit it with any text editor like Notepad or VS Code to update mirror URLs or fix checksums manually.

What software creates application/metalink4+xml files?

These files are often generated automatically by server-side scripts or repository management software (like those used by Linux distributions). However, tools like Metalink Editor or command-line utilities can also generate them.

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.