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Sign PDF

Add your signature to any PDF by drawing with mouse or finger, or upload a signature image. Place it anywhere. Free to use in the browser, and signup is not required to start.

Free in browser No sign-up required Files stay on your device
1. Upload PDF

Drop PDF here or click to upload

Files processed locally — never uploaded
How it works

Run this tool in three short steps.

01

Upload your PDF

Drop a PDF or click to browse.

02

Draw or upload signature

Draw with mouse/finger, or upload a signature image.

03

Place and download

Click on the PDF to position your signature, then download.

Questions

What people ask before they use this tool.

How does PDF signing work?
Draw your signature on the canvas or upload a signature image. The tool uses pdf-lib.js to embed the signature at your chosen position on the PDF. Processing happens in your browser, and PDF files are not uploaded to our servers during signing.
Is this a legally binding digital signature?
This tool adds a visual signature image to a PDF. It is not a cryptographic digital signature (PKI). For legally binding e-signatures, services like DocuSign or Adobe Sign provide certificate-based authentication. Our tool is suitable for informal documents, internal approvals, and quick sign-offs.
Can I draw my signature with a mouse?
Yes. The canvas supports mouse and touch input. Use your mouse on desktop or draw with your finger on mobile. You can also upload a pre-existing signature image (PNG with transparent background works best).
Can I position the signature anywhere on the page?
Yes. Click on the PDF preview to place your signature. Drag to reposition. The signature is placed at the exact coordinates you choose.
Is my PDF uploaded to a server?
No. pdf-lib.js runs in your browser. PDF files are processed locally during signing and are not uploaded to our servers.
Can I sign multiple pages?
Currently you can sign one page at a time. After downloading, you can re-upload to add signatures to additional pages.
What signature image formats are supported?
PNG (recommended, supports transparency), JPG, and WebP. For best results, use a PNG with a transparent background.
Can I change the signature size?
Yes. Use the size slider to adjust the signature width. Height scales proportionally.
Can I undo and re-sign?
Yes. Click "Clear signature" to redraw. The PDF is not modified until you click "Apply Signature".
Does it work on mobile?
Yes. Draw your signature with your finger on the touch canvas. The PDF preview and placement work on mobile screens.
What is the file size limit?
Depends on your device. Most devices handle PDFs up to 50MB comfortably.
Can I remove a signature from a PDF?
Not with this tool. Once a signature is embedded and saved, it becomes part of the PDF content. Always preview before downloading.
Does it preserve the original PDF quality?
Yes. pdf-lib.js modifies the PDF without re-rendering. Try also <a href="/edit-pdf">PDF Editor</a>. All existing content, formatting, and quality remain intact.
Is it really free?
Yes. The browser tool is free to use, and signup is not required to start.
Can I pay with cryptocurrency?
PDF tools are free. For AI writing tools, we accept USDT, USDC, BTC, ETH. Plans start at $9.99/month.
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Coda One's PDF Signer lets you add your handwritten signature to a PDF document. Draw directly on the canvas or upload a signature image, then position it on the page. It uses pdf-lib.js in your browser, and PDF files are not uploaded to our servers during signing.

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