MIME Type Lookup
How it works
"Extension → MIME type" strips a leading dot and looks up one MIME type. "MIME type →
Extension" runs the other direction and can return more than one match — .jpg and .jpeg,
for instance, are both valid extensions for image/jpeg — joined by a comma in
the copyable result.
Frequently asked questions
What is a MIME type used for?
A MIME type (also called a content type) tells a browser or HTTP client how to interpret a file's bytes — it's what a server sends in the Content-Type response header so the receiving end knows whether it just got HTML, a PNG image, or a PDF, rather than guessing from the file extension alone.
Why do some MIME types map to more than one extension?
.jpg and .jpeg are the same image format under two conventional spellings — same for .htm/.html and .yaml/.yml. Rather than arbitrarily picking one as "the" extension, the MIME-to-extension direction here returns every match.
Is this the full MIME type registry?
No — it's a fixed table of common types, not an exhaustive registry. The full IANA media type registry runs to hundreds of entries; this covers the extensions and content types a working developer runs into regularly.
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