What PDF formats and versions are supported?
Our PDF authenticity checker supports most standard PDF formats including PDF 1.3 through PDF 2.0, linearized PDFs, PDF/A (archival format), and PDF/X (print format). While older versions (PDF 1.0-1.2) may work, analysis is most reliable with PDF 1.3 and newer.
The PDF tamper detection system can analyze PDFs created by any standard PDF creation tool including Adobe Acrobat, Microsoft Office, Google Docs, LibreOffice, online PDF converters, and specialized PDF software.
Some limitations apply: password-protected or encrypted PDFs cannot be analyzed, corrupted PDFs may fail to process, and non-standard PDF variants might produce unexpected results. Our PDF modification detection works best with standard, unencrypted PDF files following ISO 32000 specifications.
← Previous
How should I interpret PDF analysis results?
Next →
How can I share PDF analysis results with others?
Related questions
Keep reading
3 answers
Reading Your Results
Each PDF authenticity check generates a unique, permanent URL that you can share with others to view the analysis results. After uploading your PDF and completing the PDF tamper detection, you'll receive a results page with a shareable link (format: htpbe.tech/result/[unique-id]).
This link provides full access to the analysis including modification status, metadata details, and all findings. You can share this link via email, messaging apps, or embed it in documents. The results page includes social sharing buttons for easy distribution.
Recipients don’t need accounts or special access—the link works for anyone. This makes it easy to share PDF modification detection results with colleagues, clients, or legal professionals.
Note: The shared link shows analysis results only, not the original PDF file, maintaining privacy while enabling collaboration on PDF authenticity analysis.
A PDF showing as “modified” doesn’t necessarily mean someone tampered with the content. Many legitimate actions create modifications that our PDF authenticity checker detects:
- Saving or exporting: Re-saving a PDF in any tool (even without changes) updates the modification date and metadata
- Format conversion: Converting from Word/Excel to PDF, or PDF to PDF/A, creates new metadata
- Adding signatures: Digitally signing a PDF creates incremental updates
- Printing to PDF: “Printing” a PDF to create a new PDF changes all metadata
- Auto-save features: Some PDF viewers auto-save which triggers modification timestamps
- Annotation or comments: Adding notes, highlights, or comments modifies the file structure
Our system detects any structural changes after the PDF was originally created. This is intentional—it helps you know the document’s complete history. A “modified” result doesn’t automatically mean fraud or tampering; it means the file has a history beyond its initial creation.
Review the detailed findings on the results page to understand what specific changes were detected and whether they align with your document’s known history.
Privacy, Data & Limits
It depends on how you submit the file. Files uploaded through the free web tool are stored in encrypted cloud storage (Cloudflare R2, hosted in the European Union) and may be retained after analysis and used, in anonymized and aggregated form, to test and improve our detection algorithm. Before a file is used for this purpose it is dissociated from your identity and any contact details. Files submitted through our public API are never stored — an API submission is fetched, analyzed once, and discarded.
What we keep for every check: the analysis results and metadata — filename, file size, creation and modification dates, creator, producer, and detected findings. Those results stay at your unique result URL so you can reference them later.
In every case our analysis is strictly structural: we examine the file’s technical layout, never the substantive content of your document, so the text of sensitive contracts, financial statements, and personal records is never read.