How accurate is PDF modification detection?

Our PDF modification detection system provides high accuracy through multi-layer analysis combining metadata validation, structural analysis, and signature verification. The accuracy depends on several factors: the quality of PDF metadata, the sophistication of modification attempts, and the PDF creation tools used.

Results come in three states: Intact (no signs of modification found), Modified (modification detected), and Cannot Verify (the PDF was created with consumer software such as Microsoft Word or LibreOffice — integrity analysis does not apply to documents created with these tools).

There is one fundamental limitation to understand: the tool detects post-creation modifications, not fabricated content. If someone creates a fake invoice or certificate from scratch in Word and exports it to PDF, that PDF will show as Intact — because it was never modified after creation. The check only tells you whether the file was changed after it was generated, not whether the data inside it is truthful. See Can someone create a fake document from scratch? for details.

For critical decisions, we recommend using this tool as part of a broader verification strategy rather than relying solely on automated results.