What is MIME type "image/heic-sequence"?

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

image/heic-sequence is a MIME type that signals a file containing a series of images stored in the High Efficiency Image File Format.
It bundles multiple frames into one container. This makes it ideal for burst photos or frames of an animation.
Files using this type benefit from advanced compression and efficient storage.

Efficient compression: Saves storage space while keeping image quality high.
Multi-frame support: Ideal for capturing sequences or bursts in one file.
Next-generation technology: Uses HEVC coding for improved performance.

It applies to files with extensions such as HEIC, HIF, HEIF, and HEICS.
This format is used by various devices to capture and store dynamic image content.

Associated file extensions

.heic, .hif, .heif, .heics

Usage Examples

HTTP Header

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


    Content-Type: image/heic-sequence

HTML

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


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

Associated file extensions

.heic, .hif, .heif, .heics

FAQs

What is the difference between image/heic and image/heic-sequence?

The primary difference lies in the content structure: image/heic usually denotes a single static image item, whereas image/heic-sequence indicates a file containing a track or series of images. This distinction allows software to immediately recognize if the file should be treated as a still photo or an animation, such as a "Live Photo" or burst shot.

Which web browsers support image/heic-sequence?

Native support is currently limited primarily to Safari on macOS and iOS devices. Major browsers like Chrome, Firefox, and Edge generally do not render image/heic-sequence files natively and require the content to be converted to widely supported formats like WebP or MP4 for web display.

How do I configure my web server to serve HEIC sequences correctly?

You must map the MIME type to the specific file extension in your server settings. For Apache, add AddType image/heic-sequence .heics to your .htaccess file. For Nginx, include image/heic-sequence heics; within the types block of your nginx.conf or mime.types file.

Why can't I open .heics files on Windows?

Windows requires specific codecs to decode High Efficiency Image File Format containers. You likely need to install the HEIF Image Extensions and HEVC Video Extensions from the Microsoft Store to view files associated with image/heic-sequence in the native Photos app.

When should I use image/heic-sequence instead of GIF?

Use image/heic-sequence when you need high-fidelity animations with a significantly smaller file size than GIF. Unlike GIF, which is limited to 256 colors, HEIC sequences support millions of colors and advanced compression, making them ideal for high-quality content like Apple's "Live Photos" stored on local devices.

What file extensions are commonly used with this MIME type?

While generic extensions like .heic and .heif are common, the specific extension .heics is often used to explicitly denote an image sequence. Using specific extensions helps operating systems distinguish between single images and multi-frame sequences without opening the file first.

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.