What is MIME type "application/x-internet-archive"?

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-internet-archive is used for files created using the Internet Archive's version 1.0 format. It indicates that the file bundles multiple digital assets, like web pages or multimedia, into a single archive.

Files marked with this MIME type use the archive extension ARC. This helps software recognize how to process and extract content from the file.

Main use: Storing and preserving snapshots of websites and online content.
Other uses: Packaging collections from digital libraries and maintaining metadata with archived files.
Technical purpose: Enabling proper file identification and extraction in archival and recovery applications.

This MIME type supports digital preservation efforts by ensuring that archived content retains its structure and metadata for future access. For more on digital archiving, visit Internet Archive.

Associated file extensions

.arc

Usage Examples

HTTP Header

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


    Content-Type: application/x-internet-archive

HTML

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


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

Associated file extensions

.arc

FAQs

What is the relationship between application/x-internet-archive and the .arc file extension?

The MIME type application/x-internet-archive is explicitly defined for ARC files, which are the legacy format (version 1.0) used by the Internet Archive for storing web crawls. An .arc file concatenates multiple network resources (like HTML, images, and HTTP headers) into a single sequence for digital preservation.

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

To ensure your Apache server sends the correct Content-Type header for Internet Archive files, add the following line to your .htaccess file or main configuration: AddType application/x-internet-archive .arc. Without this, browsers may misinterpret the file as generic binary data or plain text.

Is application/x-internet-archive the same as the WARC format?

No, this MIME type is specific to the older ARC format. The modern standard, WARC (Web ARChive), is an ISO standard that offers better handling of metadata and duplicates. WARC files typically use the MIME type application/warc instead of application/x-internet-archive.

Can web browsers open files with this MIME type directly?

Most standard web browsers (Chrome, Firefox, Edge) cannot natively render or "browse" a raw .arc file because it is a concatenation of multiple files and headers. Users typically need specialized software like the Heritrix crawler or specific playback tools (like the Wayback Machine software) to view the content properly.

Why does the MIME type start with "x-"?

The prefix x- indicates that application/x-internet-archive is a non-standard or private MIME type that was not officially registered in the IANA standards tree at the time of its creation. It was developed specifically for the Internet Archive's internal needs before the industry moved toward the standardized WARC format.

Are files with this MIME type usually compressed?

Yes, ARC files are frequently compressed to save storage space, resulting in filenames ending in .arc.gz. When serving these compressed files, you may need to configure your server to handle application/gzip or set the Content-Encoding: gzip header alongside the application/x-internet-archive type.

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.