Document Integrity Verifier
Fingerprint · Compare · Tamper Detection · Verify — 100% local
Drop any file to fingerprint
Click or drag any file
All hashing runs locally in your browser · No files are uploaded · No data is sent to any server
3 Algorithms
SHA-256, SHA-1 and MD5 generated in one pass.
Byte Compare
Prove two files are byte-identical with cryptographic hashes.
Verify Downloads
Confirm a file matches a published checksum before trusting it.
Fully Local
Files never leave your device — everything runs in-browser.
Frequently Asked Questions
What is a file fingerprint?
A fingerprint (or checksum) is a fixed-length string computed from the exact bytes of a file. If a single byte changes, the fingerprint changes completely — that's how you detect tampering or corruption.
Which algorithm should I use?
Use SHA-256 for security-critical checks (downloads, contracts, evidence). Use SHA-1 or MD5 only for compatibility with older systems — they are cryptographically broken and should not be relied on for tamper detection.
Does the file get uploaded?
No. All hashing runs in your browser using the Web Crypto API. The file bytes never touch a server.
Any file size limit?
The browser reads the whole file into memory to hash it, so very large files (>2 GB) may fail on low-memory devices. Regular PDFs and documents are fine.
What formats work?
Any file. Fingerprints work on the raw bytes, so PDFs, images, videos, ZIPs, executables — anything with a file extension — can be fingerprinted, compared and verified.
Why does copy-pasted whitespace not break verification?
The verifier strips whitespace and normalises the case of hex characters before comparing, so pasting a hash with line breaks or leading spaces still works.