MIME Type Lookup
Instantly find MIME types by file extension or look up extensions by MIME type. Free online reference with 1000+ entries.
What is a MIME type?
A MIME type (Multipurpose Internet Mail Extensions) is a standard identifier that tells browsers and servers the format of a file or data being transferred. It ensures content is handled and displayed correctly.
How is a MIME type structured?
A MIME type consists of a type and a subtype separated by a slash, such as text/html or image/png. The type indicates the general category, while the subtype specifies the exact format.
How do I find the MIME type of a file?
Enter the file extension in the search box above. The tool will instantly return the corresponding MIME type. You can also search in reverse by entering a MIME type to find its associated extensions.
What is the Content-Type header?
The Content-Type is an HTTP header that uses MIME types to tell the client what kind of data is being sent. For example, a web server sends Content-Type: text/html to indicate an HTML page.
Can one file extension have multiple MIME types?
Yes. Some extensions map to multiple MIME types depending on context. For example, .xml can be application/xml, text/xml, or application/xhtml+xml depending on usage.
How do web servers determine MIME types?
Web servers typically use a configuration file (like mime.types on Apache) that maps file extensions to MIME types. Some servers also inspect file content (magic bytes) to determine the type.
Are MIME types case-sensitive?
By convention, MIME types are written in lowercase (e.g., text/html). While the HTTP specification treats them as case-insensitive, it is best practice to always use lowercase.
What are the most common MIME types?
The most common MIME types include text/html for web pages, application/json for API data, image/jpeg for photos, image/png for graphics, and application/pdf for documents.
Who maintains the official MIME type registry?
The IANA (Internet Assigned Numbers Authority) maintains the official media type registry. All standardized MIME types are registered and published at iana.org.
Can I define custom MIME types?
Yes. Custom or non-standard MIME types use the x- prefix or the application/vnd. prefix for vendor-specific types. For example, application/x-myapp or application/vnd.openxmlformats.
What happens if the wrong MIME type is sent?
Browsers may fail to render content correctly, refuse to display it for security reasons, or attempt to download it as a file instead of displaying it inline.
What is the difference between MIME type and file extension?
A file extension is a suffix appended to a filename (like .jpg) to indicate its format. A MIME type is the formal standard used in protocols like HTTP to describe the actual data format.