Are these valid IANA media types?

Yes. Every entry comes from a built-in table of registered IANA media types such as application/json and image/png. The tool selects them at random rather than constructing arbitrary strings.

What is the structure of a MIME type?

A media type has the form type/subtype, where type is a top-level category like text, image, audio, video, or application, and subtype identifies the specific format such as png or json. Optional parameters like charset can follow a semicolon.

Why filter by category?

When you are testing image-only uploads, for example, you want sample types restricted to the image category. Filtering lets you generate realistic inputs for the exact validation path you are exercising.

Will I get duplicates?

No. Within a batch the tool samples without replacement, so each MIME type appears at most once. Requesting more than the table holds returns the full filtered set.

What is the file extension for?

Each type maps to a commonly associated file extension, such as .png for image/png. This is handy when you also need to fabricate matching filenames for upload tests, though a single type can map to several extensions in practice.

Random MIME Type Generator

Testing file uploads or a content-type allow-list? This generator hands you random, valid IANA media types — optionally filtered to one category — along with a typical file extension for each.

How it works

An IANA media type takes the form type/subtype. The top-level type is one of a small set of categories (text, image, audio, video, application), and the subtype names the specific format. This tool keeps a table of registered types and samples from it:

filter the table to the chosen category (or keep all)
shuffle and take the first N entries
render the type/subtype string and its extension

Because the entries come from a real table, the strings you get are ones a browser or server would actually emit in a Content-Type header.

Tips and notes

Remember that a Content-Type may include parameters after a semicolon, most commonly a charset such as text/html; charset=utf-8. When validating uploads, match on the type/subtype portion and treat the extension as a hint only — never trust it as proof of the real format.