Sign PDF

What is an electronic signature?

An electronic signature is an image, typed name, or other mark indicating that a specific person has agreed to the contents of a document. The legal definition is intentionally broad — typed initials at the end of an email, a tick-box on a checkout page, and a hand-drawn signature on a PDF all qualify in most modern jurisdictions. Three laws set the global pattern: the United States E-SIGN Act (2000), the European Union’s eIDAS regulation (2014), and India’s IT Act amendments. All three accept electronic signatures for routine commercial documents and put two requirements on the signer: clear intent to sign, and consent to use the electronic form.

For most everyday documents — NDAs, freelance contracts, rental agreements, vendor onboarding, expense reports — an electronic signature is what the other party expects and what every PDF reader displays correctly. For specific high-stakes documents (wills, real- estate title transfers, certain court filings) the rules tighten; check your jurisdiction and document type before assuming an electronic signature is enough.

What this tool does

This is a fully browser-side electronic-signature tool. You drop a PDF, draw or type your signature, click on the page to position it, and download a signed copy. Every step happens locally:

1. The PDF is parsed by pdf-lib (and previewed by pdf.js) on your CPU. No upload.
2. The signature is captured by a <canvas> element. Drawing input comes from pointer events (mouse, finger, stylus) — captured in the browser, never transmitted.
3. The signature canvas is rasterised to a transparent PNG, embedded into the PDF via pdf-lib.embedPng, and stamped on the chosen page at the chosen coordinates.
4. The signed PDF is handed back as a downloadable Blob.

The original PDF is not modified — you keep the source file untouched, and the signed version is a new file you save.

Common use cases

• Routine contracts. Vendor agreements, NDAs, freelance contracts, rental leases. The signer is the originator, the workflow is one-sided, the legal weight is electronic-signature level.
• Internal company forms. Expense reports, HR onboarding, internal approvals. Speed matters, the paperwork is private, and the recipient is internal.
• Acknowledgement-style returns. Reading agreements, code-of- conduct sign-offs, training completion confirmations.
• Document review feedback. Stamp a signed approval on the cover page of a reviewed document before forwarding it.

For full multi-party negotiation flows (track-changes, sequential signing, audit trails), reach for a hosted tool like DocuSign or Adobe Sign. This is a one-shot signing tool, not a workflow platform.

How to use this Sign PDF tool

1. Drop a PDF onto the dropzone. The first page is rendered as a preview underneath. If the PDF is encrypted you’ll be told to unlock it first (use the PDF Password Remover tool).
2. Create your signature. Two modes:
   • Draw — sketch with mouse, finger or stylus. Adjust pen thickness with the slider.
   • Type — type your name. It renders in a script-style font that approximates a hand signature.
3. Pick the page. Use the Prev / Next buttons on multi-page PDFs.
4. Click where you want the signature. A cyan box previews the placement at the size you’ve chosen.
5. Adjust signature size. The size slider sets the width in PDF points; height auto-scales to the signature’s aspect ratio.
6. Click Sign PDF. The signed PDF is built locally and a Download button appears.

Security and signing notes

The signature image is embedded as part of the PDF content stream — it is overlaid on top of the existing page content, not woven into the page’s text layer. A determined recipient with a PDF editor could in principle remove the image; the same is true of any image-based electronic signature, including the ones produced by Adobe Acrobat Reader’s drawn-signature tool. The legal weight comes from the document trail (what was sent to whom, when, and what was accepted in return), not from the immutability of the image itself.

For tamper-evident signing, you need a digital signature that binds a cryptographic certificate to the document — see Adobe Sign, DocuSign, or self-signing with openssl. That is a separate workflow from this one.

Privacy

Your signature drawing, the original PDF, and the signed PDF all stay on your device. There is no upload, no server-side processing, no analytics on the document’s contents. The Cloudflare network serves the page’s static assets; after those load, the only thing talking is your browser and your CPU.

Compatibility notes

The output is a standard PDF 1.7 file. Every PDF reader displays the signature image at the right place on the right page — Adobe Acrobat, Apple Preview, the built-in PDF viewers in Chrome / Edge / Firefox / Safari, mobile PDF readers, even older systems. Printing works identically.