PDF Core is built with a privacy-first architecture. All file processing happens in your browser — nothing is uploaded, stored, or seen by us.
Your files are never sent to our servers. They stay on your device the entire time.
We don't watch what you do. No behavioral tracking, no marketing pixels, no profiling.
We have no database of your files or activity. There's literally nothing to leak.
Here's exactly what happens when you use our tools
You choose a file from your device
JavaScript processes it in your browser
You get the processed file instantly
Multiple layers of protection to keep your data safe
All connections to our site are secured with modern TLS/SSL encryption to prevent man-in-the-middle attacks.
Files are processed by JavaScript running in your browser, never on external servers.
We don't maintain a database of users or files. There's simply nothing to breach or steal.
No cookies for tracking, no fingerprinting, no behavioral analysis of your usage.
Built with the latest web security standards, CSP headers, and secure coding practices.
Our site is served as static files with no server-side processing of user data.
A closer look at the technology powering our privacy-first approach
We use PDF.js (by Mozilla) to render PDFs and pdf-lib to modify them. Both libraries run entirely in your browser's JavaScript engine. Your PDF files are loaded into browser memory (RAM), processed locally, and the result is offered as a download. Nothing is transmitted.
Modern browsers have incredibly powerful JavaScript engines. By processing files locally, we skip the roundtrip of uploading to a server, waiting for processing, and downloading. Your file doesn't have to travel across the internet — everything happens instantly on your device.
Once you've loaded a tool page, it can continue working even if your internet disconnects. The processing happens locally, so an internet connection isn't required after the initial page load. (*The page itself needs to load first, but processing is offline-capable.)
Files are loaded into browser memory temporarily. When you close the tab, browsers automatically free up this memory. No traces of your file remain on your device or ours. Modern browsers also isolate memory between tabs for additional security.
When you use tools like Unlock PDF or Protect PDF, passwords are processed locally in your browser. We never see your passwords or the unlocked content. Everything happens on your device with your keys.
We use well-established, open-source libraries: PDF.js (Mozilla), pdf-lib, JSZip, and others. These have been audited by the community and are used by millions of applications worldwide. Their security is battle-tested.
Because your privacy is non-negotiable
✓ They stay on your device
✓ We have no file storage system
✓ No signup ever required
✓ No tracking scripts used
✓ We don't have data to sell
✓ No ad networks integrated
✓ We don't profile users
✓ Nothing to share
You can verify this yourself! Open your browser's Developer Tools (F12) → Network tab. Then use any of our tools. You'll see that no file upload requests are made to our servers. All processing happens locally in your browser.
PDF Core is safe for confidential documents like contracts, tax returns, medical records, legal papers, and business documents. Since files never leave your device, they remain as confidential as they were on your computer.
No — because your files are never on our servers to begin with. There's no database to hack, no file storage to breach, no user accounts to compromise. It's the most secure architecture possible.
Yes! When you use tools like Unlock PDF, the password is processed entirely in your browser. We never see the password or the unlocked content. Everything happens on your device.
Since processing happens in your browser, the file size limit depends on your device's memory (RAM). Most modern devices can handle PDFs up to 100MB+ without issues. Larger files may take longer to process but will still work.
Because we don't collect, process, or store personal data or files, most privacy regulations don't apply to us in the traditional sense. Users maintain full control over their data at all times, which aligns with the principles of GDPR, CCPA, and similar laws.
You can prove our privacy claims in 30 seconds
Press F12 or Right-click → Inspect on any tool page
Click the 'Network' tab in developer tools
Upload a file and see — no upload requests to our servers
Complete transparency. Your privacy is provable.
Join thousands who trust PDF Core with their confidential documents.
Why Choose Us?
We built our tools to make your PDF work smarter, not harder. All tools are free and work right in your browser.
Learn MoreFiles are processed locally in your browser. Nothing is uploaded.
Our tools are optimized for speed so you can get things done quickly.
Everything works online. No downloads or installations required.
Use our tools on any device, anytime, anywhere.
Explore our free PDF tools — no signup required, no hidden costs.