Flatten PDF Forms Online — Free & Private
Convert editable PDF forms into permanent, non-editable content. Protect filled forms from tampering and ensure document integrity — all in your browser.
Why Choose Our PDF Flatten Tool?
True Privacy
Your forms stay on your device. Unlike online tools that upload your sensitive documents, LocalPDF processes everything locally in your browser.
Prevent Tampering
Lock filled data permanently, making it impossible for recipients to alter your form submissions or annotations.
Universal Compatibility
Flattened PDFs are static and render consistently across all PDF viewers and operating systems, ensuring your document looks as intended.
No Data Loss
Our tool preserves all visual content, text, and layout during the flattening process, ensuring no information is lost or distorted.
Instant Processing
No upload delays or waiting times. Flattening happens at native speed directly in your browser, providing immediate results.
Professional Results
Achieve clean, finalized documents suitable for official submissions, archiving, or sharing where data integrity is paramount.
Key Features
How It Works
100% Private Sandbox: Your files never leave your device. All processing happens locally in your browser's secure memory.
Frequently Asked Questions
Are my files uploaded to a server?
Never. All processing happens 100% locally in your browser. Your files stay on your device, ensuring total privacy and security.
Is there a limit on file size?
There are no artificial limits. The only constraint is your device's available memory. Most modern computers and phones can handle large PDF files without issues.
Does it work on mobile devices?
Yes! LocalPDF Sanctuary is fully responsive and works on iOS, Android, and tablets through any modern web browser.
Technical Architecture: How it Works
Zero-Knowledge Architecture
Our system is designed so that your data is never seen by anyone else. Processing happens in the browser's secure memory space.
WebAssembly Performance
We use high-performance WebAssembly modules to achieve desktop-grade PDF processing speeds directly in your web browser.