Sign PDF Online
Add your signature or text to any PDF document — free, private, and instant. Your files never leave your device.
What Is a PDF Signer?
A PDF signer lets you add visual signatures, initials, and text annotations to PDF documents. This is commonly used for contracts, agreements, forms, and any document that requires a personal mark. TweakFiles processes everything in your browser using pdf-lib and PDF.js — your PDF and signature never leave your device.
Unlike services like DocuSign or Adobe Sign that upload your documents to their servers, TweakFiles keeps everything client-side. This makes it faster, more private, and completely free. There are no accounts to create, no monthly fees, and no limits on the number of documents you can sign.
Types of Signatures You Can Add
TweakFiles supports two ways to add your mark to a PDF:
- Draw signature — Use your mouse, trackpad, or touchscreen to draw a freehand signature. The drawing pad captures your natural handwriting style.
- Type text — Type your name, date, initials, or any text and place it anywhere on the page. Useful for filling in form fields or adding notes.
Common Use Cases
PDF signing is useful for a wide range of documents:
- Contracts and agreements — Add your signature to close deals without printing
- Tax forms and government documents — Sign and submit digitally
- School permission slips and consent forms — Quick parental signatures
- Lease agreements and rental applications — Sign from anywhere
- Internal approvals and sign-offs — Streamline business workflows
Privacy and Security
Your PDF is processed entirely in your browser. The file is read locally, pages are rendered to canvas elements, and your annotations are embedded using pdf-lib — all without any network requests. Your signature data stays on your device and is never transmitted or stored anywhere.
How to Sign a PDF in 3 Steps
Upload Your PDF
Drag and drop your PDF file or click to browse. Your file is read directly in your browser — nothing is uploaded.
Add Your Signature or Text
Draw your signature on the pad or type text, then click anywhere on the page to place it. Drag to reposition and resize using the corner handle.
Download Signed PDF
Click download to save your signed PDF with all annotations permanently embedded in the document.
TweakFiles vs Other PDF Signing Tools
| Feature | TweakFiles | DocuSign | Adobe Sign | Smallpdf |
|---|---|---|---|---|
| Price | Free forever | $10–$40/mo | $12.99–$22.99/mo | Freemium ($9/mo) |
| Signup Required | No | Yes | Yes | Yes (free tier) |
| File Privacy | 100% client-side | Cloud-based | Cloud-based | Cloud-based |
| Draw Signature | Yes | Yes | Yes | Yes |
| Type Text | Yes | Yes | Yes | Yes |
| Drag & Resize | Yes | Yes | Yes | Limited |
| Watermark | None | None (paid) | None (paid) | Watermark (free) |
| Offline Support | Yes | No | No | No |