Sign PDF Free — private & local
Browser-based signing. Your files never leave your device.
Upload your PDF
100% local processing — your file stays on your device, never uploaded to any server
Why choose our local PDF signer?
100% Local Processing
Your PDF is processed entirely in your browser. Zero server uploads - we literally cannot see your files.
Private by Design
Pure client-side technology. The file is never uploaded; the page only sends anonymous error and performance diagnostics, never the file itself or its name.
Free & Unlimited
No signup, no limits, no hidden costs. Because signing runs in your browser, the tool costs us almost nothing to run.
How local PDF signing works
Unlike other PDF signing tools that upload your files to their servers, our tool processes everything in your browser using client-side JavaScript.
- 01
Select file locally
Your PDF is loaded directly into your browser's memory using the File API, and the file never leaves your device. The page itself still downloads the PDF viewer and font files it needs and sends anonymous diagnostics, but never your file.
- 02
Browser-based processing
Your signature is captured on an HTML Canvas and embedded into the PDF using pdf-lib — a pure JavaScript library running entirely in your browser.
- 03
Direct download
The signed PDF is generated on your device and downloaded directly. The file itself never reaches our servers.
Your documents are never processed on our servers or sent over the internet. Open your browser's Network tab to verify — you'll see the page load its viewer, fonts and diagnostics, but no file uploads.
Need to Send Documents for Others to Sign?
Our full e-signature platform lets you send documents for signature, track status in real-time, and maintain secure audit trails.
Frequently asked questions
- Is my PDF file uploaded to any server?
- No. Your PDF is processed 100% locally in your browser using client-side JavaScript, and the file never leaves your device. We cannot see, access, or store your documents because they never reach our servers. The page does send anonymous error and performance diagnostics (for example, which font failed to render), but never the file itself or its name.
- How does local PDF signing work technically?
- Our tool uses modern browser technologies (JavaScript, Canvas API, pdf-lib library) to process your PDF entirely on your device. When you select a file, it's loaded into your browser's memory - not uploaded anywhere. Your signature is drawn on an HTML canvas, then embedded into the PDF using pdf-lib. The final signed PDF is generated on your device and downloaded directly. No internet upload ever occurs.
- Is this tool really free? What's the catch?
- Yes, 100% free with unlimited usage forever. The 'catch' is actually a benefit for you: because signing happens locally in your browser, the tool costs us almost nothing to run. No signup, no credit card, no email required. Use it unlimited times.
- Is the electronic signature legally valid?
- Electronic signatures may have legal effect in many countries under laws like ESIGN (US), eIDAS (EU), and Canadian provincial e-commerce legislation such as the Ontario Electronic Commerce Act, 2000, depending on the jurisdiction and document type. For documents requiring audit trails, timestamp verification, or multi-party signing workflows, consider our full e-signature platform.