Paperlane
瀏覽工具

PDF 指紋

Work with your PDF directly in the browser—fast, private, and without uploading the document.

local不需要帳戶

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Privacy & limitations

Your files stay on this device

A fingerprint only proves byte-for-byte identity. Re-saving, printing to PDF, or any edit changes the hash even if the visible content looks identical — compare hashes only for files you expect to be exactly the same bytes. SHA-1 and MD5 are provided for compatibility with legacy systems only. Both are cryptographically broken and must never be trusted as a security or authenticity guarantee, here or anywhere else. The digest covers the uploaded bytes alone; Paperlane does not validate the PDF's internal structure. Two files that look identical on screen but were encoded differently will have different fingerprints.

How to use this tool

  1. Add the PDF you want to fingerprint. The digest is computed over the exact bytes you upload — Paperlane never re-encodes or alters the file, so the result is a true byte-for-byte identity check.
  2. Choose the algorithms to compute. SHA-256 is always included and is the recommended fingerprint; add SHA-512 when you want a stronger digest. SHA-1 and MD5 are offered only as clearly labeled legacy compatibility hashes for older systems that still ask for them.
  3. Copy the digest you need, or paste an expected hash (for example, one published on a vendor's website) into the comparison box to check whether this file matches it before you trust or use it.
  4. Verify independently on your own machine: on macOS run `shasum -a 256 your-file.pdf`, on Linux run `sha256sum your-file.pdf`, and on Windows run `certutil -hashfile your-file.pdf SHA256`. The hex output must match the value shown here exactly, ignoring letter case.