What is MIME type "application/x-sea"?

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

The MIME type application/x-sea indicates a file that is a Self-Extracting Archive. This type of file combines compressed data with a built‐in extraction routine.

When you open a file with this MIME type, its built‐in program extracts the contents automatically. It does not require a separate decompression tool.

It packages many files into one executable container.
It simplifies file distribution and installation.
It is useful for software installers and bundled data collections.

Files with this MIME type typically use the extension SEA. Always verify the source before running such files, as they contain executable code.

For more technical details on MIME types, visit MIME on Wikipedia.

Associated file extensions

.sea

Usage Examples

HTTP Header

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


    Content-Type: application/x-sea

HTML

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


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

Associated file extensions

.sea

FAQs

What is the primary function of the application/x-sea MIME type?

This MIME type identifies a Self-Extracting Archive, which combines compressed files with a small executable program. Unlike standard archives, files sent as application/x-sea do not require separate software to decompress; the user simply runs the file to extract its contents.

How do I open an application/x-sea file on modern operating systems?

Since many .sea files were created for older systems (like classic Mac OS), the built-in executable may not run on Windows 10 or macOS Sonoma. Instead of running it, use a third-party archive tool like The Unarchiver (macOS) or 7-Zip (Windows) to open the file and extract the data manually.

Are files with the application/x-sea content type secure?

You should treat these files with caution because they contain executable code. Malware can hide inside self-extracting archives, so only download and run application/x-sea files from trusted sources or scan them with antivirus software before opening.

How do I configure an Apache server to serve .sea files correctly?

To ensure browsers handle these files as binary downloads, add the following directive to your .htaccess file or httpd.conf: AddType application/x-sea .sea. This prevents the server from sending them as generic text or binary streams.

What is the difference between application/x-sea and application/zip?

While application/zip is a passive data format requiring an unzip tool, application/x-sea is an active program that unzips itself. However, .zip is now preferred for web distribution because it avoids the security risks and platform compatibility issues associated with executable archives.

Can Nginx serve application/x-sea files?

Yes, you can add the MIME type to your mime.types file in the Nginx configuration directory. Add the line application/x-sea sea; to ensure clients recognize the file type correctly when downloading.

Why does my browser warn me when downloading an application/x-sea file?

Browsers often flag application/x-sea downloads because they are executables (programs). Security features like Google Safe Browsing or Microsoft SmartScreen may warn you that the file type could harm your computer, as it is capable of executing code upon opening.

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.