PDF Sign

About PDF Sign

PDF Sign lets you electronically sign PDF documents without uploading them anywhere. Open the tool, draw your signature on the canvas using a mouse, trackpad, or touchscreen, then click on the PDF page exactly where you want the signature to appear. The tool stamps each signature as a transparent PNG image directly into the PDF using pdf-lib — the full document never leaves your browser. Build a small library of reusable signatures, drop the same one in multiple spots (or mix several across pages), then drag each placement to fine-tune its position and drag the corner handle to resize it. Page through the document with the navigation row, preview every placement live, and download a signed file ready to email or archive. This is the fastest way to handle a one-off signature when you do not want to install Adobe Acrobat, hand the document to a third-party SaaS, or print/scan/sign/scan again. Works on phones, tablets, and laptops in any modern browser. Files are processed locally — UtilityKit never sees the original or signed copies.

Why use PDF Sign

How to use PDF Sign

1. Upload the PDF you want to sign — files up to 50 MB are accepted and stay in your browser.
2. Click anywhere on the page (or the Sign button) to open the signature dialog, then draw your signature in the canvas pad with a mouse, trackpad, or touchscreen.
3. Click Use signature to drop it on the page — it is saved to your signature library so you can reuse it elsewhere.
4. Drag the signature to reposition it, drag the bottom-right handle to resize it, or use the × to remove it.
5. Page through the document with the navigation row and add more signatures wherever they are needed.
6. Click Apply & Download — the signed file downloads instantly with no upload.

When to use PDF Sign

• When signing a one-off NDA, freelance contract, or rental agreement and you do not want to install desktop PDF software.
• When you need to sign a confidential or legally privileged document that must not be uploaded to a third-party SaaS.
• When you receive a PDF for signature on your phone and need to return it within minutes.
• When the document only needs a visual signature mark, not a cryptographically verified digital certificate.
• When school, HR, or government forms ask you to print, sign, scan and resend — and you can skip every step.
• When you want to add initials, a visible 'approved' mark, or a simple drawn stamp on multiple PDFs in a row.

Examples

Tips

• Sign in landscape mode on a tablet for the most natural-looking signature — the wider canvas captures more nuance.
• Set the width slider to roughly match the printed signature line under the signature box for the cleanest result.
• If your signature looks jagged on a high-DPI display, try drawing more slowly so each stroke is captured smoothly.
• For two signatures on the same document (e.g. signature + initials), download the signed file then re-upload it and add the second mark.
• Always keep the original unsigned PDF until you have verified the signed copy looks correct on a desktop viewer.

Frequently Asked Questions

Explore the category

Glossary

Electronic Signature

A digitised mark or image placed on a document to indicate intent to sign — distinct from a cryptographic digital signature with PKI.

pdf-lib

An open-source JavaScript library that creates and modifies PDF documents directly in the browser.

Canvas Pad

An HTML5 canvas element used to capture freehand drawing input from a mouse, trackpad, or touchscreen.

Embed PNG

Insert a transparent PNG image into a PDF page — what happens when your signature is added.

Page Coordinates

The X/Y position on a PDF page where the signature is placed, measured in PDF user-space units from the bottom-left corner.

Saddle-Stitch Output

Unrelated to signing — but useful if you later print the signed PDF as a booklet, see PDF Booklet Imposition.