MIME Type Finder
Match common file names and extensions with media types, or inspect a Content-Type value while keeping filename conventions separate from actual file-content detection.
Try app.js, archive.tar.gz, .json, application/json, or text/html; charset=utf-8.
Bundled mappings
47
Registered/common table entries
45
Common web-only mappings
2
Media Type Result
Common mappings are bundled for quick lookup; the IANA registry contains many more registered media types.
Extension or media-type details will appear here.
A Filename Can Suggest a Format; It Cannot Prove One
A media type describes transferred content. A filename extension is only a naming convention. Renaming HTML, executable data, or a ZIP archive to photo.jpg does not turn those bytes into a JPEG image.
That distinction is important in upload handling. Extension checks are useful for user feedback, but security-sensitive validation needs server-side inspection appropriate to the format and safe storage and serving rules for user-controlled content.
Content-Type Has a Type, a Subtype, and Sometimes Parameters
In Content-Type: text/html; charset=utf-8, text/html is the media type and charset=utf-8 is a parameter. Parameters are defined by the media type's specification; they are not a universal list that can be copied from one type to another.
Pasting the full Content-Type: field is accepted, but lookup is performed on the base type/subtype. A wildcard such as image/* is different: it is a media range used in negotiation fields such as Accept, not a concrete Content-Type for one representation.
archive.tar.gz Describes Two Layers
The last extension in archive.tar.gz describes the outer gzip layer, so .gz maps to application/gzip. The filename still does not prove that the decompressed bytes form a TAR archive. Compound names are best read as processing hints rather than byte-level evidence.
Registration and Common Web Usage Are Not the Same List
IANA maintains the authoritative registry of media-type names, but it is not a universal filename-extension database. Some extension mappings come from platform or browser conventions, and some widely seen web values are not main-registry registrations.
For example, text/javascript is the registered JavaScript type and IANA marks application/javascriptobsolete in its favor. application/yaml is registered for YAML. Values such as audio/wav and video/webm are common in web software but are kept clearly separate from claims about IANA registration.
+json and +xml Tell You About Syntax, Not Registration
A structured syntax suffix can let generic software recognize an underlying representation family. A subtype ending in +json signals JSON-based representation semantics;+xml does the same for XML. That suffix does not by itself prove that the complete media-type name is registered or appropriate for a particular protocol.
SVG and MIME Sniffing Need Separate Security Decisions
image/svg+xml is an image media type, but SVG is XML-based and can contain active features. Upload rules that treat every image/* value as an inert bitmap can therefore create a security boundary that is much weaker than it looks.
Browsers can also apply MIME-sniffing behavior in some contexts when a response type is absent or ambiguous. A filename lookup does not reproduce those algorithms. For a live HTTP problem, inspect the real Content-Type, X-Content-Type-Options, request context, and browser behavior.
When the Exact Registration Matters
The IANA Media Types registry is the place to confirm whether a type/subtype is registered, obsoleted, or associated with a particular specification. The registration framework is described by RFC 6838, while individual types often point to their own defining RFC or standards document.
Only the Text You Enter Is Examined
Lookup runs against bundled mapping data in the browser. A file is not uploaded or opened, a URL is not fetched, and no content sniffing is performed. If a path or URL is pasted, only its text is used to find the apparent extension. Site-wide analytics or advertising scripts, if enabled, are separate from that lookup.