PDF and privacy guides
Practical explanations, reproducible tests and resources to understand what really happens to a PDF document when you use an online tool.
Published guides
How to tell if a PDF tool uploads your documents
Learn to distinguish local processing from remote transfer using offline mode, network traffic, POST/PUT, blobs and canary documents.
Read the guide → Practical guideLocal vs server processing: what really happens to your PDF
Understand where a PDF operation runs, how to identify remote transfer and what an offline test can actually prove.
Read the guide → Practical guideHTTPS does not mean your PDF is not uploaded to a server
Learn what HTTPS actually protects and why an encrypted connection does not prove that your document stays on your device.
Read the guide → Practical guideTelemetry, analytics and document transfer are not the same
Learn to interpret network traffic and distinguish small metrics from actual PDF document transfer.
Read the guide → Practical guideWhat does it really prove when a PDF tool works offline?
Learn the difference between preloading a tool and a true offline cold start, and what each test can prove.
Read the guide → Reproducible studyPrivacy Lab and PDF tools observatory
Explore our methodology, evidence and comparative test of the same operation across several online PDF services.
Open Privacy Lab →