Verify a capture

Captures saved in ScreenGrab's evidence mode come with a receipt (.evidence.txt) holding each file's SHA-256 fingerprint and, when certified, a timestamp file (.tsr). Drop them here with the capture to check that it hasn't changed since.

The check runs entirely in your browser. Your files are not uploaded anywhere.

Drop the capture, its receipt and its .tsr file here or click to choose them

Checking the authority's signature

This page checks that the certified timestamp is for this exact file and reads the time it certifies. To also check the timestamping authority's digital signature, use OpenSSL (built into macOS and Linux):

openssl ts -verify -data "capture.png" -in "capture.png.tsr" -CAfile /etc/ssl/cert.pem

On Linux the CA file is usually /etc/ssl/certs/ca-certificates.crt. OpenSSL prints Verification: OK when the file, the time and the signature all check out.