Document Integrity Verifier
Fingerprint · Compare · Tamper Detection · Verify — 100% local
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Drop any file to fingerprint
Click or drag any file
✓ No upload✓ No watermark✓ No sign-up
Feeding PDFs to an AI support agent?
helpGPT answers your customers' questions from your own docs, with citations and honest refusals.
1Fingerprint any fileHash any file locally — SHA-256 integrity, nothing uploaded.
2CompareCompare two files or hashes to spot any change instantly.
3Verify hashPaste an expected hash and confirm your file matches.
Fingerprint any file in your browser
Drop any file and get its SHA-256 digest locally — share the hash alongside the file so recipients can confirm nothing changed.
Compare and verify without uploading
Paste two hashes to compare them, or paste a published hash to verify your copy — every check runs on this device, nothing leaves your browser.
How to document Integrity Verifier
- 1Upload your PDFUpload the PDF you want to fingerprint.
- 2Generate hashThe tool automatically calculates SHA-256, SHA-1, and MD5 hashes simultaneously.
- 3Copy the fingerprintCopy the hash values and store them securely — in a separate document, email, or trusted system.
- 4Verify laterRe-upload the document in the future and compare hashes. If they match, the file is unchanged. Any difference means it was modified.
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Frequently asked questions
How does fingerprinting work?
Each copy gets subtle unique variations — in metadata and spacing — that identify its recipient without visible changes.
Can a recipient remove it?
A determined actor may strip markers; fingerprinting raises the bar, it is not DRM.
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Read the free PDF guides — step-by-step walkthroughs for this tool and more.