ANALYSIS VERIFICATION DIAGNOSTIC

Checksum Lab

Compute CRC32, MD5, SHA-1, SHA-256, and SHA-512 for a file. Paste a known hash — or a whole checksum manifest — to auto-verify, or load a second file to diff the two directly. Large files are hashed in chunks so the page stays responsive. Everything runs in your browser.

File A

Common error messages this diagnoses

If you're here because something threw one of these, this tool shows you exactly what's wrong and how much is recoverable:

  • "Checksum mismatch" — the file's hash doesn't match what was expected — this tool computes and compares five algorithms at once.
  • "MD5 hash does not match" — same idea — verify a specific known-good hash.
  • "SHA256 verification failed" — common on package/installer downloads — verify against the publisher's published hash.

What this tool deliberately doesn't check

A hash match only proves the file is byte-for-byte identical to whatever you compared it against — it can't vouch for the reference hash itself being trustworthy. CRC32 is included mainly because formats like ZIP and PNG embed it internally, not because it's a good general-purpose integrity checksum on its own. This tool can't tell you a file is structurally wrong, only that its bytes differ from what you expected — pair it with the Unknown File Identifier or Hex Damage Map for that. Large files take real time to hash — chunked processing keeps the page responsive, but it doesn't make reading and hashing every byte instant.