What is MIME type "multipart/x-tar"?

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

multipart/x-tar is a MIME type that signals an archive bundled in separate segments.
It is used to combine many files and directories into one package while retaining the data structure and file metadata.
This format allows software to treat each part of the archive individually yet as a cohesive unit.

File Archiving: Combines multiple files into a single archive.
Backup and Distribution: Ideal for grouping files for backups or transferring software packages.
Data Preservation: Retains original file structures and permissions within one container.

Although the more common MIME type for such archives is often application/x-tar, some systems use multipart/x-tar when the archive is segmented into parts, which can assist with streaming or incremental transfers.
Users typically work with this type when handling TAR archives on their PCs.
This MIME type helps archiving tools and file managers know exactly how to process and extract the individual parts of the archive.

Associated file extensions

.tar

Usage Examples

HTTP Header

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


    Content-Type: multipart/x-tar

HTML

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


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

Associated file extensions

.tar

FAQs

What is the multipart/x-tar MIME type used for?

This MIME type indicates a Tape Archive (TAR) file that may be bundled in separate segments or parts. While the standard type is application/x-tar, the multipart prefix is sometimes used by specific applications to denote that the archive is split into chunks for streaming or storage. It is most commonly associated with the .tar file extension.

How does multipart/x-tar differ from application/x-tar?

application/x-tar is the standard, IANA-registered media type for TAR archives, while multipart/x-tar is a non-standard variation. Developers often use the multipart subtype when the archive is physically split into multiple files or streams, but most modern archive managers handle both types similarly.

How do I open a file received with the multipart/x-tar content type?

You can open these files using standard archiving tools like 7-Zip, WinRAR, or the native tar command line utility on Linux and macOS. Even if the MIME type suggests a multipart structure, the file is typically recognized as a standard .tar archive once saved to your computer.

Why does my browser force a download for multipart/x-tar links?

Web browsers do not have built-in capabilities to display or extract TAR archives. When a server sends the multipart/x-tar header, the browser correctly identifies it as a binary data package that requires external software, automatically triggering the Save File dialog.

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

To maximize compatibility, it is usually better to serve these files as the standard application type. You can define this in your .htaccess or httpd.conf by adding: AddType application/x-tar .tar. If you specifically require the multipart definition for a legacy system, use AddType multipart/x-tar .tar instead.

Can I change the MIME type from multipart/x-tar to application/x-tar without breaking the file?

Yes, changing the MIME type header on the server does not alter the actual file content. If your users are experiencing issues with web applications not recognizing multipart/x-tar, switching the server configuration to send application/x-tar is a safe and recommended fix.

Is multipart/x-tar secure?

The MIME type itself is just a label, but TAR archives can contain any type of file, including malware or scripts. Always scan downloaded .tar files with antivirus software before extracting them, regardless of whether they were served as multipart or application types.

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.