File hash generator and PDF fingerprint checker
Use the file hash generator to fingerprint a PDF or another file, compare exact bytes or verify a known hash. You can also add an ID to a PDF copy. Free to use, with no sign-up required.
Files processed on your device01 How it works
- Add one or more files.
- Choose hash, compare, verify or tag.
- Download the report or file.
02 Good to know
A hash changes when the file bytes change. Tagging adds an invisible ID to PDF metadata and page content; it can help identify a tagged copy if the mark remains, but it can be removed.
03Choose a fingerprint task
Get SHA-256, SHA-1, SHA-512 and MD5 hashes for a file, compare hashes from two files, or verify a file against a hash you already have.
A hash identifies the exact file bytes. Saving the file again or changing its metadata can produce a different hash, even if the pages look the same.
04Tag a PDF copy for a recipient
The tagging option adds an ID to PDF metadata and page content. Keep the reported ID with the recipient record if you need to check a recovered copy later.
A tag is not encryption or access control. It can be removed, and a matching ID only helps identify a copy where the mark remains.
05Use hashes for exact file checks
To verify integrity, compare the calculated hash with a trusted value obtained separately. A matching hash means the bytes match for that algorithm; it does not establish who created the file or whether its contents are true.
06 Questions
What does a PDF fingerprint tell me?
A file hash identifies its exact bytes. If any bytes change, its hash will normally change too.
Can I compare two files by their hashes?
Yes. Compare their hashes, or verify one file against a known hash value.
Does tagging stop someone from sharing a PDF?
No. Tagging adds an identifier that may help trace a copy if it remains. It does not restrict access and can be removed.