Which MIME types are related to file extension ".mht"?
The .mht file extension is associated with 3 MIME types:
message/rfc822, application/x-mimearchive, multipart/related.
A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.
About .mht Files
MHT files are files that bundle a complete webpage or email message into one archive. They use MIME encoding to merge HTML text, images, and other resources.
MIME Types and Their Roles:
- message/rfc822: Indicates the file can store email message content.
- application/x-mimearchive: Marks the file as a MIME archive for HTML content.
- multipart/related: Shows that multiple related parts such as images and CSS are combined in one container.
MHT files are primarily used to save entire webpages exactly as seen in a browser. They are also known to archive emails and similar MIME-based content. Many users open these files with browsers like Internet Explorer or use applications such as Microsoft Word and various email clients to view or edit them.
Based on information from FilExt.com, MHT files offer a convenient way to keep all parts of a webpage together in one file for easy sharing and offline viewing.
Relationship between file extension and MIME type
A file extension is a suffix at the end of a filename that indicates what type of file it is. File extensions help both users and operating systems identify what application should be used to open the file.
File extensions are typically separated from the filename by a period (dot) and consist of 2-4 characters, though they can be longer. For example, in the filename "document.pdf", ".pdf" is the file extension.
File extensions are closely related to MIME types, as they both serve to identify the format of a file. However, while MIME types are used primarily by web browsers and servers, file extensions are used by operating systems and applications.
Associated MIME types
message/rfc822, application/x-mimearchive, multipart/related
FAQs
How do I open an .mht file on Windows 10 or 11?
You can open .mht files natively using Microsoft Edge (often requires Internet Explorer mode), Internet Explorer, or Microsoft Word. Since these files are essentially web archives, they display the original webpage content combined with images and styling.
Can I view MHT files in Google Chrome or Mozilla Firefox?
Native support is limited; Chrome and Firefox often require specific extensions (such as "IE Tab") to render .mht files correctly. Without extensions, the browser might simply download the file or attempt to display raw text instead of the visual webpage.
How do I convert an MHT file to PDF?
Open the file in Microsoft Word or a compatible browser, then select Print and choose "Microsoft Print to PDF" or "Save as PDF". This preserves the layout of the multipart/related archive in a universally readable format.
Is there a difference between .mht and .mhtml extensions?
No, they are interchangeable file extensions for the same MIME HTML format. The .mht extension is a legacy artifact from older Windows operating systems that strictly enforced three-letter file extensions.
Why is my MHT file identified as an email?
MHT files use the same encoding standards as email messages, often utilizing the message/rfc822 MIME type. This is why email clients like Microsoft Outlook can open, edit, and display them as if they were standard email messages.
How can I create an MHT file?
In supported browsers (like Internet Explorer or older versions of Edge), use the "Save As" feature and select Web Archive, single file (*.mht). This packs the HTML, CSS, and images into a single file rather than creating a separate folder for resources.
Are MHT files safe to open?
You should be cautious, as MHT files can contain malicious scripts embedded within the HTML content just like a live webpage. Only open these archives if they come from a trusted source, similar to how you would treat an email attachment.
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 can one extension have multiple MIME types?
Different programs and historical usage may assign various MIME identifiers to the same file format. Listing them together helps maintain compatibility across tools.