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

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

application/x-arc denotes an archive file type. It tells software that a file contains multiple bundled items, often compressed to save space.
This MIME type usually applies to legacy or specialized archiving tools. It is not an official IANA standard but is commonly seen with older compression utilities.
Files tagged with this type may use extensions such as ARC, ARK, or SUE.

Bundling files: Groups multiple files into one package.
Data compression: Often compresses contents to reduce file size.
Backup and transfer: Facilitates easy storage, backup, and exchange of data.

This MIME type helps programs recognize how to open and handle the archive. For more details on archive file formats, visit Filext.com.

Associated file extensions

.arc, .ark, .sue

Usage Examples

HTTP Header

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


    Content-Type: application/x-arc

HTML

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


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

Associated file extensions

.arc, .ark, .sue

FAQs

What is the application/x-arc MIME type used for?

The application/x-arc MIME type represents archive files created by legacy compression utilities, such as System Enhancement Associates (SEA) ARC. These files bundle multiple items into a single package, similar to modern ZIP files, but use older compression algorithms.

Which file extensions are commonly associated with application/x-arc?

This MIME type is primarily associated with the .arc extension. It may also be seen with .ark or .sue files depending on the specific software version or platform used to create the archive. See more at arc.

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

To ensure your Apache server sends the correct header, add the following line to your .htaccess file or main configuration: AddType application/x-arc .arc. This ensures browsers treat the file as a binary archive to be downloaded.

Can web browsers open application/x-arc files natively?

No, modern web browsers (like Chrome, Firefox, or Edge) cannot view or extract ARC archives internally. When a server sends the application/x-arc header, the browser will trigger a download prompt so the user can save the file locally.

How do I open an application/x-arc file on Windows or macOS?

Since ARC is a legacy format, built-in operating system tools often cannot open it. You will typically need a third-party multi-format archiver such as 7-Zip, PeaZip, or The Unarchiver (on macOS) to extract the contents.

What does the "x-" prefix mean in application/x-arc?

The x- prefix indicates that this is a non-standard or experimental subtype that was not officially registered with the IANA when it was defined. While newer standards often omit this prefix, legacy types like application/x-arc retain it for backward compatibility.

Is application/x-arc secure to use?

Like any archive format (such as TAR), an ARC file acts as a container and can conceal malware or viruses inside the compressed data. You should always scan downloaded archives with antivirus software before extracting them.

Should I use application/x-arc for new web projects?

Generally, no. This is considered an obsolete format with lower compression efficiency compared to modern standards. For current projects, utilize widely supported types like ZIP or GZIP to ensure maximum compatibility for your users.

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.