Doc Notary

Guides

Plain-language guides to proving when a file existed and checking that a file is the original, including free methods that don't need Doc Notary.

How to timestamp a document and prove when it existed

What works, what doesn't (file dates, emailing yourself), and step-by-step free options.

How to check if a file has been changed

Compare a file's SHA-256 fingerprint on Windows, Mac, Linux or in your browser, and read the result correctly.