WorkbenchA useful little toolbox.

Identify a file

Find a file format from its contents, even without an extension.

Processed on your device. No file upload.
Choose a file to get started

Drop it here, or use the file picker.

How to use this tool

  1. Choose your file or try the example.
  2. Run the tool and check the result.
  3. Save the result where a download is available.

Supported features & limits

Checks signatures for PDF, images, archives, audio, video and common document formats. ZIP-based documents are inspected for known entries. Unrecognized formats are reported as unknown. Only the first 64 KB is read for general signatures; ZIP inspection is limited to 10 MB.

What happens to my files?

Your browser reads the file locally. File contents are not sent to our server. Closing or resetting this page clears the working result. Downloaded copies remain on your device.

Maintained by Roman Zmazhenko. Updated 1 November 2026.