What is MIME type "application/x-par2"?

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

application/x-par2 is a MIME type from the Parity Volume Set File Format Family.
It handles error correction and data recovery for file groups. Parity files store extra data that can repair missing or corrupted parts of a file set.
Main uses include:

Error correction: Restores lost data using redundant parity information.
Data verification: Checks file integrity during downloads and archival storage.
Reliable distribution: Widely used in communities like Usenet and file-sharing networks.

Files that use this type include PAR, PAR2, PA3, PXX, and PAR3.
This approach boosts data reliability and is especially useful when file sets must be preserved accurately over time.
Learn more about PAR2 technology.

Associated file extensions

.par, .par2, .pa3, .pxx, .par3

Usage Examples

HTTP Header

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


    Content-Type: application/x-par2

HTML

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


    <a href="file.dat" type="application/x-par2">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-par2');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.par, .par2, .pa3, .pxx, .par3

FAQs

What software is required to open application/x-par2 files?

You cannot open these files with a standard text editor or media player. You need specialized data recovery tools like QuickPar (Windows), MultiPar, or MacPAR deLuxe (macOS). These programs use the .par2 file to verify and repair a set of downloaded archives.

How do I configure Apache to serve PAR2 files correctly?

To ensure browsers handle the file as a download rather than text, add the MIME type to your .htaccess file or global configuration. Use the line: AddType application/x-par2 .par2 .par. This instructs the server to send the correct header.

Why does my browser download the file instead of displaying it?

Browsers like Chrome, Firefox, and Edge do not have native support for parity volume sets. Since application/x-par2 is a binary format used for error correction, the browser defaults to downloading the file so you can process it with a local utility.

How do I add support for PAR2 files in Nginx?

Open your mime.types file or the types block in your nginx.conf. Add the following line: application/x-par2 par2;. After saving the file, reload Nginx to apply the changes and allow users to download the files properly.

Can I delete application/x-par2 files after downloading?

Yes, but only after you have verified and repaired your target files. Once the .par2 or .par files have successfully reconstructed any missing or corrupted data in your file set, they are no longer needed and can be safely deleted to save space.

What is the difference between PAR and PAR2?

While both use similar MIME types, PAR2 is the modern standard that allows for more efficient recovery. Unlike the older .par format, PAR2 can repair data using blocks of variable size, meaning you don't need a 1:1 match of recovery files to missing files.

Is the application/x-par2 MIME type a security risk?

Generally, no. These files contain mathematical checksums and recovery data, not executable code. However, you should always ensure that the actual content files you are repairing (such as .rar or .zip archives) come from a trusted source.

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.