ConvertDuck

Securely Sign Documents in Your Browser

Handling contracts and agreements shouldn't compromise your privacy. Our tool allows you to add legally binding-style signatures to any PDF without ever uploading your sensitive files to a remote server. By using the PDF-Lib engine directly in your browser, your documents stay on your device, ensuring complete confidentiality while providing a seamless signing experience for freelancers and businesses alike.

How to Sign Your PDF in 3 Steps

1. Upload Document

Select the PDF file you need to sign. It loads instantly in our secure viewer.

Files up to 50MB are processed smoothly on most modern devices.

2. Create Signature

Choose between drawing with your mouse/touchscreen, typing your name, or uploading a high-quality signature image.

Drawing usually provides the most personalized feel for formal contracts.

3. Place & Download

Drag the signature to the correct line, adjust its size, and download your signed document.

You can place multiple signatures on different pages before downloading.

Why Professionals Choose Our Signer

  • ✓ Client-Side Privacy

    Unlike major competitors, we don't 'see' your PDF. All rendering and signing happen locally using your browser's CPU.

  • ✓ Multi-Mode Signing

    Flexible options: Draw a signature for authenticity, type for speed, or upload a pre-scanned PNG for consistency.

  • ✓ Mobile Optimized

    Use your smartphone or tablet's touchscreen for a natural drawing experience that mimics real pen and paper.

Technical Requirements

Compatibility Chrome, Firefox, Safari, Edge
Core Library PDF-Lib & PDF.js (v3.11+)
File Formats PDF (Standard & Encrypted)
Privacy 100% Local Execution (Offline Capable)

Local Signing vs Cloud Services

Feature This Tool (Local) Cloud Signature Tools
Privacy Files never leave device Stored on cloud servers
Speed Instant (No upload) Upload/Download wait times
Cost Free Forever Monthly Subscriptions
Limits Device RAM limited Server handles 100MB+

Common Questions About PDF Signing

Q. Is this signature legally binding? ▼
In many jurisdictions, electronic signatures are legally binding for general business use, but we recommend checking local regulations for deeds or specific legal documents.
Q. Does this work without an internet connection? ▼
Yes. Once the page is loaded, you can disconnect and finish signing because everything happens in your browser.
Q. Will my signature image be saved? ▼
No. Your signature data exists only in your current browser session and is wiped when you refresh the page.
Q. Can I sign an encrypted PDF? ▼
Standard encrypted PDFs are supported for viewing, but some highly restricted permissions might block saving.