Verify a file hash
This page lets anyone - a judge's clerk, opposing counsel, or you - confirm that a file matches the SHA-256 hash printed on an ExhibitKit exhibit. The file is hashed locally in your browser; it is never uploaded.
Your browser's hashing engine (crypto.subtle) is only available over HTTPS or on localhost. Reload this page over HTTPS.
1. Choose the file
Drop the file here, or click to choose
Any file type. Hashing happens on this device only.
Hashing…
Computed SHA-256:
2. Paste the expected hash
Copy the full 64-character hash from the exhibit's certification page (or cover page) and paste it here.
What a matching hash proves - and what it doesn't
A SHA-256 hash is a fingerprint of a file's exact bytes. If the hash of the file you just dropped matches the hash printed on the exhibit, the file is byte-for-byte identical to the source file that was hashed when the exhibit was prepared - even a one-character edit would produce a completely different hash. What a hash does not prove is who wrote the messages inside the file, or that the export itself was complete and unaltered before it was hashed. Those questions are matters of testimony and authentication, which is why ExhibitKit pairs every exhibit with a declaration template.
To double-check independently on a computer: on a Mac, run shasum -a 256 yourfile in Terminal; on Windows, run certutil -hashfile yourfile SHA256 in Command Prompt; on Linux, sha256sum yourfile. All should print the same 64 characters shown above.