Are online PDF tools safe?
Most online PDF tools work by uploading your file to a server, processing it there, and sending it back — which means your document (and whatever's in it) leaves your device. PDFER is different: every tool runs entirely in your browser, so files are never uploaded.
The risk with upload-based tools
When a site uploads your PDF, you're trusting its servers, retention policy, and staff with the contents — a real concern for contracts, IDs, medical, or financial documents. Even with deletion promises, the file still travelled over the network and sat on disk.
How in-browser processing is different
PDFER uses WebAssembly and JavaScript to do everything locally. Your file is read into memory on your device, processed there, and erased when you leave the page — it never touches a server. You can even work offline after the page loads.
This is verifiable: a strict Content-Security-Policy blocks any cross-origin network request, so the app couldn't upload your file even if it tried.
Tools mentioned in this guide
Frequently asked
- Do online PDF tools upload my files?
- Most do — they process on a server, so your file leaves your device. PDFER runs in your browser instead, so nothing is uploaded.
- How can I verify a PDF tool is private?
- Check whether it works offline and whether it makes network requests when you use it. PDFER's strict content-security policy blocks all cross-origin requests, so files can't be sent anywhere.
- Is PDFER really free with no signup?
- Yes — no account, no watermarks, no daily caps. Processing happens on your device, so there's no server cost per file.