What is MIME type "application/zstd"?

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

The MIME type application/zstd shows that a file uses the Zstandard compression algorithm. This format compresses data efficiently without losing any information.
Files in this format must be decompressed before they can be used.

Supports fast compression and decompression
Enables efficient backup and storage
Helps in speeding up file transfers
Suitable for both small and large data sets

Files using this MIME type have an extension like ZST.

Associated file extensions

.zst

Usage Examples

HTTP Header

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


    Content-Type: application/zstd

HTML

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


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

Associated file extensions

.zst

FAQs

How do I open a file with the application/zstd MIME type?

Files with this MIME type are compressed archives. On Windows, you can open them using 7-Zip or WinRAR (ensure you have the latest version). On Linux or macOS, use the command line tool zstd -d filename.zst to decompress the data.

Is application/zstd supported by web browsers?

Yes, modern browsers like Chrome, Edge, and Firefox support Zstandard as an HTTP Content-Encoding method to speed up page loads. However, if a server sends a raw file with the Content-Type: application/zstd header, the browser will typically prompt the user to download the file rather than displaying it.

How do I configure Nginx to serve .zst files correctly?

To ensure Nginx serves the correct MIME type, add the definition to your mime.types file or inside a types block in your server configuration. Use the directive: types { application/zstd zst; } to map the extension.

What is the difference between application/zstd and application/gzip?

While both are compression formats, Zstandard (application/zstd) generally offers better compression ratios and faster decompression speeds than application/gzip. Zstd is a newer standard designed to scale effectively for real-time data transfer and high-performance storage.

Should I use application/x-zstd or application/zstd?

You should use application/zstd. The x- prefix (e.g., application/x-zstd) indicates an experimental or non-standard type. Since Zstandard is now IANA-registered, the official application/zstd is the correct identifier for standard compliance.

How do I add Zstd support to an Apache web server?

You can map the file extension by adding AddType application/zstd .zst to your .htaccess file or main configuration. If you wish to use Zstd for real-time output compression, you will need to enable specific modules that support the Zstandard algorithm.

Are there security risks associated with application/zstd files?

Like any compressed format, Zstd files can hide malware or be structured as "decompression bombs" designed to exhaust system memory. Always scan downloaded zst files with antivirus software before decompressing them.

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.