Local Security tool
Document Integrity
Document Integrity is a local checksum tool. Use it before you send a contract, after a download, or when you want to prove two copies are byte-for-byte the same. Hashes never leave this tab.
Fingerprint · Compare · Tamper detection · Verify — 100% local
All hashing runs locally in your browser. No files are uploaded. No data is sent to any server.
Private by design. Your files stay on this device and are never uploaded.
How it works
How Document Integrity works
Document Integrity is a local checksum tool. Use it before you send a contract, after a download, or when you want to prove two copies are byte-for-byte the same. Hashes never leave this tab.
Guided steps
How to use Document Integrity
- 1Choose Fingerprint, Compare, or Verify Hash.
- 2Drop a file (or two files to compare). Any type is allowed.
- 3Read the SHA-256 or SHA-512 hex digest computed in this browser.
- 4Copy the hash or paste an expected value to confirm a match.
Questions
Document Integrity FAQs
Does hashing upload my file?
No. Web Crypto runs in this tab. There is no hash API and no server-side store.
What does Compare tell me?
If two hashes match, every byte is the same. If they differ, the files are not identical. That is tamper detection, not a legal signature.
Which hash should I paste to Verify?
A 64-character hex string is treated as SHA-256. A 128-character hex string is treated as SHA-512. Spaces and 0x prefixes are ignored.
Continue locally
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