Add Signature to PDF — E-Sign Documents
Add your handwritten signature to PDF documents. Works on desktop and mobile. Free and private.
Place your digital signature on any page of a PDF document. Choose from drawing, typing, or uploading an image of your signature. Position and resize it freely before saving. No printing, scanning, or Adobe Acrobat needed.
Drop a PDF to sign
PDF files only
How It Works
Upload a PDF document, draw your signature on the built-in canvas pad using your mouse, stylus, or finger (on touchscreens), then position it precisely on any page. The drawn signature is converted to a transparent PNG and embedded into the PDF using pdf-lib.js — no server interaction, no account required.
Fine-tune the signature placement with slider controls for size, horizontal position (X), and vertical position (Y). Select which page to sign using the page navigator. The real-time preview shows exactly where your signature will appear on the document before you commit.
The signed PDF preserves all original content — text, images, fonts, form fields, and annotations remain unchanged. Your signature is added as a transparent image overlay that sits on top of the existing page content. Download the signed document instantly.
Features
- ✓Touch-friendly signature canvas — draw with mouse, stylus, or finger on any device
- ✓Place signature on any page in multi-page documents
- ✓Precise positioning with X/Y sliders and adjustable signature size
- ✓Real-time preview shows exact placement before downloading
- ✓Preserves all original PDF content, formatting, and form fields
- ✓Transparent signature background — sits cleanly over document content
- ✓Instant download with no watermarks, no branding, no limits
- ✓100% client-side — your PDF and signature never leave your device
How to Use This Tool
- Upload the PDF document you need to sign. The tool accepts any standard PDF file.
- Draw your signature on the canvas pad using your mouse, stylus, or finger. Click Clear to redo if needed.
- Use the page selector to choose which page to sign, then adjust the size and position (X/Y) using the sliders. The preview updates in real time.
- Click "Apply Signature" and download your signed PDF. The document is ready for sending, printing, or archiving.
Perfect For
- →Freelancers and contractors signing service agreements, NDAs, and project proposals before sending to clients
- →Remote workers signing HR documents, expense reports, and time sheets without printing and scanning
- →Parents signing school permission slips, medical forms, and enrollment documents digitally
- →Real estate agents adding signatures to listing agreements, disclosure forms, and buyer representation contracts
- →Small business owners signing purchase orders, vendor agreements, and lease documents
- →Students signing financial aid forms, housing applications, and internship agreements
- →Notaries adding signature stamps to witnessed documents for record-keeping
- →Personal use: signing rental applications, insurance claims, and government forms without a printer
Under the Hood
The signature pad uses a Canvas element that captures mouse/touch events (mousedown, mousemove, touchstart, touchmove) and renders smooth Bézier curves between sampled points. The drawing is exported as a transparent PNG using canvas.toDataURL('image/png'), preserving the anti-aliased edges of the signature.
The PDF signing operation uses pdf-lib.js to: (1) parse the source PDF's cross-reference table and page tree, (2) embed the signature PNG as a PDF image object, (3) create an image draw operation at the specified coordinates and dimensions on the selected page, and (4) serialize the modified PDF for download. All existing page content, fonts, images, and annotations are preserved.