File-Extension.info is an independent reference about file formats and extensions. For any format it answers three practical questions: what the file is, which programs open it, and how to convert it. It has been online since 2014.
Who runs it
The site is founded and edited by Adam B., a graduate of the Warsaw University of Technology. He has been passionate about the web since 2004, building all kinds of online projects and tools ever since. In 2012 he turned that focus specifically to file formats and extensions, and in 2014 he launched File-Extension.info.
How entries are verified
The approach is deliberately concrete. Wherever possible, format details are checked on real systems: sample files are opened, the programs that claim to support them are tested, and technical facts such as MIME types, magic bytes and structure are cross-referenced against primary documentation.
The tools
Alongside the reference, the site offers a small set of free file tools: a file identifier, an image converter, a checksum tool and a Base64 encoder.
Get in touch
Spotted something that needs fixing, or have a format worth adding? Reader corrections are one of the main ways the reference stays accurate. Use the contact page or email [email protected].