Private integrity tool

Prove whether a file changed without uploading it.

Create or compare a SHA-256 fingerprint for a PDF or any supported file while every byte stays on this device. Copy the value, compare an original with a received file, or verify a published fingerprint. A match proves the compared bytes are identical to the referenced value; it does not prove authorship, safety, legality, or that the published value is trustworthy.

FileChoose any filePDFs and all other file types

SHA-256 is the value to publish and compare

A fingerprint is derived from the exact file bytes. One changed byte produces a different value. SHA-1 and MD5 remain available for compatibility with older systems, but they should not be chosen for adversarial security decisions.

Generate

Record the SHA-256 fingerprint before distributing a contract, report, evidence file, or release artifact.

Compare

Choose two files and receive an unambiguous byte-for-byte identical or different verdict.

Verify later

Paste a known fingerprint or use the local audit history. Source files are never retained.

What a matching fingerprint does and does not prove

Matching SHA-256 values provide extremely strong evidence that two files contain the same bytes. They do not prove who authored the file, whether the contents are truthful, or whether the original file was trustworthy. Store the expected fingerprint separately from the file it protects.

Continue your workflow

These available PdfEditorOnlineFree tools are connected to fingerprint file by the tool catalog.