File Extension Finder
Look up a file extension to see its full type name, MIME type, and category from a curated list of common file extensions.
How the File Extension Finder Works
Type a file extension — with or without the leading dot — and the tool looks it up in a curated list of common file types, showing its full type name, MIME type, and general category (Document, Image, Audio, Video, Archive, Code, Executable, or Font). This is a name-based reference lookup, not an inspection of an actual file.
Example
Typing docx (or .docx) shows "Microsoft Word Document", MIME type application/vnd.openxmlformats-officedocument.wordprocessingml.document, in the "Document" category.
Common Use Cases
- Quickly checking what an unfamiliar file extension means before opening it.
- Finding the correct MIME type for a file extension when configuring a server or upload form.
- Learning which general category (image, document, archive, etc.) an extension belongs to.
FAQs
- Does this tool inspect an actual file? No — this is purely a name-based reference lookup against a curated list of extensions. If you want to identify a file by its actual byte content (which works even with the wrong or missing extension), use our File Type Identifier tool instead.
- What if my extension isn't listed? The list covers around 80 of the most common file extensions. Very obscure or proprietary formats may not be included — a friendly "not found" message appears in that case.
- Can one extension have more than one possible file type? In the real world, yes, occasionally — but this tool shows the single most common interpretation of each extension for simplicity.