What is MIME type "image/x-exr"?

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

image/x-exr is the MIME type for files using the OpenEXR format. It supports high dynamic range (HDR) imaging that captures a wide range of brightness and color details.

This format stores image data with high precision. It often uses floating-point numbers for pixel values. This helps keep subtle light and shadow details intact. It is widely used in professional imaging pipelines for motion pictures and visual effects.

HDR imaging: Captures a broad intensity range for deeper color and light detail.
Multi-channel support: Allows storage of separate layers or channels for advanced compositing.
High precision: Uses 16-bit or 32-bit float values to represent pixel data accurately.
Professional workflows: Common in film editing, visual effects, and digital content creation.

Files with this MIME type are commonly saved with the EXR extension. See the OpenEXR official website for more technical details.

Associated file extensions

.exr

Usage Examples

HTTP Header

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


    Content-Type: image/x-exr

HTML

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


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

Associated file extensions

.exr

FAQs

Do web browsers support image/x-exr files natively?

No, standard web browsers like Chrome, Firefox, and Safari do not natively display image/x-exr files. To show OpenEXR content on the web, you must typically convert the files to formats like png or jpeg, or use specialized JavaScript/WebGL libraries to parse and render the data.

How do I configure Apache or Nginx to serve .exr files?

You need to map the file extension to the MIME type in your server settings. For Apache, add the line AddType image/x-exr .exr to your configuration or .htaccess file. For Nginx, add image/x-exr exr; to your mime.types file to ensure the server sends the correct header.

What software can open files with the .exr extension?

Files associated with image/x-exr are primarily used in professional graphics workflows. They can be opened and edited with Adobe Photoshop (often requiring a plugin), Blender, GIMP, DaVinci Resolve, and high-end compositing software like Nuke or Fusion.

Why is the MIME type written as image/x-exr instead of image/exr?

The x- prefix stands for "experimental" or "extension," indicating that the MIME type is not a standard type registered with the IANA. While the community widely accepts image/x-exr for OpenEXR files, it technically remains a vendor-specific or non-standard subtype.

When should I use image/x-exr over image/png?

Use image/x-exr when you need to preserve High Dynamic Range (HDR) data, floating-point precision, or multiple image channels (like depth or normals) for post-production. Use png for final web display, as it is universally supported but lacks the dynamic range and bit-depth of OpenEXR.

Are image/x-exr files compressed?

Yes, OpenEXR files support various compression methods, both lossless (like ZIP or RLE) and lossy (like DWAA/DWAB). This allows the format to store massive amounts of high-precision pixel data while managing file size, making it ideal for visual effects pipelines.

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.