Security & cryptography
PDF signature checker
Read signature certificates from a local PDF and attempt CMS signed-byte integrity verification.
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Using this tool
Inspect parseable signatures and signed bytes in a local PDF.
Example
Selecting a synthetic fixture without /ByteRange yields this notice; it is not a trust certification.
Example action and settings
Action: Select file
Input / action
Synthetic unsigned PDF fixture: %PDF-1.4 %%EOF
Result / expected behavior
No supported /ByteRange signatures found. This does not prove the absence of other signature formats.
Scope and limitations
- Files are limited to 20 MiB and processing to 32 signatures.
- Trust chains, revocation, trusted timestamps, visual content, and legal validity are not checked.
Common mistakes
- A certificate or passing digest does not imply trust; a signature may not cover later appended content.
Related tools
Hash text RSA key pair generator
Privacy and browser support
Input is processed in this browser. Do not use real keys or active sensitive credentials as demonstration data. Device features require browser support and your permission.