What is MIME type "image/png"?

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

The MIME type image/png signals that a file uses a lossless image format. This means images display in high quality without losing detail during compression.

Files in the PNG family are commonly used online and in desktop applications. The format supports transparency and a broad color range, making it ideal for graphics like logos and icons. It is recognized and rendered by most web browsers and image programs.

Lossless Compression: Preserves all image data without quality loss.
Transparency Support: Enables clear or semi-transparent backgrounds.
Broad Compatibility: Works with most software and browsers.
Animation Capability: The APNG variant adds support for animated images.

The standard file version is referenced by the PNG extension. For a variant that holds animations, the APNG extension is used. These links lead to details on file handling and characteristics.

For more detailed technical insights, see the Portable Network Graphics article on Wikipedia.

Associated file extensions

png, apng

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="image/png">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

png, apng

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.