File Extension Lookup

File Extension Lookup

Instantly identify any file type by its extension. Search a database of 500+ file extensions to find descriptions, MIME types, and which programs open them on Windows, macOS, and Linux.

How to Use

Type a file extension (like .docx or .mp4), a MIME type, or a keyword (like “video” or “image”) into the search box. Results appear instantly as you type. Use the search mode and popularity filters to narrow results. Click any result to see full details including associated programs.

Features

• 507-extension database – Comprehensive coverage of common and rare file formats
• Fuzzy search – Find extensions by name, MIME type, description, or category
• Program recommendations – See which apps open each file type on Windows, macOS, and Linux
• MIME type cross-reference – Look up extensions by their MIME type
• Popularity indicator – Filter between common and rare extensions
• CSV export – Download the full extension database for offline use