PDF & Document Hash
Calculate the hash value of a PDF, Word, Excel or any document, and prove later that it has not changed.
In short
- Select the PDF or document in the tool below.
- Keep SHA-256 selected and press [CALCULATE HASH].
- The 64-character code shown is the hash value. Copy it, or paste an expected value in the verify box to check it.
- For a document to file or attach, press [GENERATE REPORT] and download the PDF.
The file is read by your browser and never uploaded.
[1] SELECT FILE(S) TO HASH
Select one or multiple files to hash from your system, or drag and drop files below. Pick two files to check whether they are identical.
[2] CHOOSE YOUR HASH FUNCTION
[3] LAUNCH THE HASHING PROCESS
Need to keep this file private? Encrypt it in your browser with CryptFile.Online, the sister tool — nothing is uploaded there either.
Why hash a document
A document's hash value lets anyone check, later and independently, that they have exactly the same file. Typical uses:
- ›Sending a contract, a tender or a filing: state the SHA-256 in the email or the cover letter, and the recipient can confirm that what they opened is what you sent.
- ›Producing a document as evidence, with its hash value on the certificate and a hash report attached.
- ›Archiving: store the hash next to the file and you can detect silent corruption years later.
- ›Telling two versions apart: two files with the same hash are identical, whatever their names.
Opening is fine, re-saving is not
Opening, reading or printing a PDF does not change it. Saving it again almost always does, even if you changed nothing, because the program rewrites the file: modification date, internal identifiers, compression. The same applies to Word and Excel files, which also store the author, the last-saved time and the editing history.
So hash the exact file that will be sent, filed or produced, after its last save. "Print to PDF" or "Export as PDF" creates a brand-new file with its own hash value each time you run it.
Hash value vs. PDF digital signature
A digitally signed PDF (for example one signed with a DSC) contains a hash too, but a different one: the signature covers the document's content and is embedded inside the file, and a PDF reader checks it for you. The hash value this tool calculates covers the whole file, signature included, and is written down outside the file.
They complement each other. The signature says who signed it; the file hash lets anyone confirm that a copy is byte-for-byte the same file, without special software.
Not a password tool
Searches for "PDF hash extractor" sometimes mean extracting the password hash of an encrypted PDF in order to crack it. This site does nothing of the kind. It calculates the checksum of the file as a whole, which works the same for encrypted and unencrypted PDFs and reveals nothing about the password or the contents.
Checking from the command line
The recipient does not need this site to check your hash value. Every operating system can do it:
Windows
certutil -hashfile contract.pdf SHA256
macOS
shasum -a 256 contract.pdf
Linux
sha256sum contract.pdf
FAQ
Does the hash of a PDF change if I rename it?
No. The name is not part of the file's content. Renaming, moving, copying or emailing it keeps the same hash value.
Why did the hash change after I opened and closed the file?
Some programs save automatically or offer to save on closing, which rewrites the file. Viewing alone does not change it. Keep a read-only copy of the version you hashed.
Is my document uploaded to calculate the hash?
No. The document is read and hashed inside your browser and never leaves your device, which makes this safe for confidential documents.
Can I hash many documents at once?
Yes. Select them all, or a whole folder, and export one hash report listing every document with its hash value.