What is MIME type "application/pdf"?

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

The MIME type application/pdf tells a computer how to handle documents in the Portable Document Format. It ensures that text, images, and layout stay the same no matter which device or software is used.
Files using this MIME type are most often PDF files. Some AI files from Adobe Illustrator can also use it because they share similar foundations.

Uniform display: Documents appear consistently across platforms.
Preserved layout: Fonts, images, and formats remain unchanged for printing or viewing.
Broad compatibility: Works well with browsers, readers, and graphic tools.
Secure sharing: Trusted for official and archival documents.

This MIME type lets operating systems and web browsers know to launch a PDF viewer or plug-in so you can see the document exactly as intended. For more details on PDF and its usage, visit Adobe or check out FileInfo.

Associated file extensions

pdf, ai

Usage Examples

HTTP Header

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


    Content-Type: audio/ogg

HTML

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


    <a href="file.dat" type="application/pdf">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', 'text/plain');
      res.end('Content here');
    }).listen(3000);

Associated file extensions

pdf, ai

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.