Verify a File SHA-256 Checksum

Choose one file up to 100 MB to calculate its SHA-256 digest in your browser. If you have a checksum from a trusted source, paste its 64 hexadecimal characters to see whether the two values match. A match checks byte-for-byte agreement with that value; it does not establish who supplied the expected checksum.

How to use File Seal

1. Choose a local file or use the built-in abc sample to see a known result.
2. Wait for the calculated SHA-256 digest, then paste a trusted 64-character hexadecimal checksum if you want a comparison.
3. Read the match result and copy the calculated digest, or clear the file to start again.