Your files never leave your device
Most online PDF tools work by uploading your file to a server, processing it there, and sending the result back. PDFCure doesn’t — the compressing, merging, signing, converting and everything else happens directly in your browser tab. Here’s exactly what that means.
Most PDF tools
- 1Your PDF
- 2Uploaded to their server
- 3Processed on their server
- 4Sent back, downloaded
A copy of your file exists on a server you don’t control
PDFCure
- 1Your PDF
- 2Processed right in your browser tab
- 3Done — download it
Your file never exists anywhere but your device
What’s actually doing the work
There’s no magic here — the tools are built on the same open-source libraries a desktop app would use, compiled to run inside a web page instead:
- • pdf-lib and pdf.js read and write the PDF itself — merging, splitting, compressing, signing.
- • Tesseract, compiled to WebAssembly, does OCR entirely offline once loaded.
- • Image conversion and editing runs on the Canvas API your browser already has.
None of that requires a network request. Load a tool, then disconnect from the internet — most of them keep working.
See it for yourself
Don’t take our word for it — this takes under a minute:
- Open any tool, like Compress PDF.
- Open your browser’s DevTools (F12, or right-click → Inspect) and switch to the Network tab.
- Load a file and run the tool.
- Watch the Network tab — no request carries your file’s contents anywhere.
The one honest exception
The AI tools — Summarize, Ask your PDF, and Translate — send your document’s extracted text to Claude to generate a response. There’s no way around this; understanding a document requires a model to read it. That’s why those tools require signing in with Google and carry a daily limit, while every other tool on the site needs neither.
Questions
Is this really true, or just marketing language?
You can verify it yourself in under a minute — see the DevTools steps below. Open any tool, load your file, and watch the Network tab: there's no request carrying your file's contents anywhere.
What data does leave my device, then?
Only page views and anonymous usage events for analytics (never file contents), and — only if you sign in and use the AI tools — the extracted text you're summarizing, translating, or asking about, sent to Claude to generate a response.
Why do the AI tools need my file's text at all?
Summarizing, translating, or chatting with a document requires a language model to read it. There's no way to do that without the text reaching a model somewhere — so those specific tools are the one deliberate exception, and they're opt-in, behind a sign-in, with a daily limit.
Does that mean the AI tools aren't private?
It means they work differently from the rest of the site, and we say so plainly rather than blur the line. Every non-AI tool — merge, compress, sign, OCR, convert, and 150+ others — never sends your file anywhere.