Frequently Asked Questions

Absolutely. This is the most important feature of pdfup. All processing happens 100% locally in your web browser. Your files are never uploaded to any server, which means we—or anyone else—can never see them. Your privacy is guaranteed.

Yes, it's completely free, and there's no catch. There are no hidden fees, no subscription plans, no usage limits, and no premium-only features. We believe essential tools should be accessible to everyone.

After you load the website for the first time, most tools will work completely offline! Because all the processing libraries are loaded into your browser, you can disconnect from the internet and continue to merge, split, compress, and edit your PDFs securely. Some niche tools that require external data (like Markdown to PDF with web images) may need a connection.

No, we do not impose any artificial limits on file size, the number of files, or how many times you can use a tool. The only practical limitation is the processing power and memory of your own computer, as very large or complex files may take longer to process.

Failures are rare but can happen for a few reasons:

• The PDF might be corrupted or not compliant with standard specifications.
• The file could be encrypted with a password you don't have. Please use our Decrypt tool first.
• The file might be a special "XFA" or dynamic form-based PDF, which some of our tools cannot process.

We care about your privacy, and we're transparent about what we collect. Two kinds of analytics are in play:

• Cloudflare Web Analytics — always on, cookieless aggregate page-view counts. No device fingerprinting, no cross-site tracking, no personal profile, so it needs no consent.
• Google Analytics 4 and Microsoft Clarity — optional and off by default. They set cookies and identifiers (Clarity also records session replays and heatmaps) and are loaded only after you press "Accept" in the banner on your first visit.

If you press "Reject", nothing from Google or Microsoft is loaded and we remember your choice in your browser. You can change it at any time with Manage cookie preferences on our Privacy Policy page. Your PDF files are still processed 100% locally in your browser and are never uploaded, so neither their contents nor their names are ever part of any analytics data.

pdfup is built on the power of modern web technologies. We primarily use JavaScript libraries like PDF-lib.js and PDFKit.js that are compiled to run efficiently in your browser via WebAssembly. This allows for powerful, server-like processing without your data ever leaving your machine.