Check a fingerprint
Every screenshot in a Copycat Watch evidence log has a fingerprint: a code worked out from the file itself. Drop the file here to see its fingerprint, then compare it with the log.
Nothing is uploaded. The fingerprint is worked out right here on your device. We never see the file.
Paste the code or the long SHA-256 from the log and we'll say if the file matches.
What a match shows
- The same file always gives the same fingerprint. Change one pixel, crop it, or save it again and the fingerprint changes.
- A match means the file is the one the fingerprint was made from, not changed by a single pixel since. The date comes from our log, which says when it was captured and which page it shows. A fingerprint can't prove a date on its own, or what happened to a file before it was made.
- No match? Phones and chat apps often shrink a picture when you send it. A shrunk copy is a new file, so it won't match. Check the original from your log folder.
A fingerprint shows a file hasn't changed. It isn't legal advice, and a lawyer or board decides what they accept.
Check it without us
SHA-256 is a public standard, so any computer can check it without this page:
- Windows:
certutil -hashfile "file.png" SHA256 - Mac:
shasum -a 256 "file.png"
Both print the long SHA-256. The short code is its first 12 characters in a phone-friendly alphabet, the same way Paper Trail match codes work.
Someone posing as you? Copycat Watch looks for fakes of you every month, fills in the reports, and keeps a dated log where every screenshot has a fingerprint. The first check is free.