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

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

The MIME type application/x-ustar signals an archive created in the ustar format. This format is a standardized version of the traditional tar archive, which packages multiple files into one container while keeping file attributes like permissions and ownership intact.

Its design supports POSIX standards. It preserves metadata for each file, making it ideal for system backups and software distributions on Unix-like systems.

Used to create reliable backups and archives.
Facilitates the distribution of complete software bundles.
Ensures file metadata remains consistent across systems.

Files in this format are often labeled with the USTAR extension. They can be processed by various archive utilities on multiple platforms.

Additional details about the tar and ustar formats can be found on resources such as Wikipedia.

Associated file extensions

.ustar

Usage Examples

HTTP Header

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


    Content-Type: application/x-ustar

HTML

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


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

Associated file extensions

.ustar

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.