Sign PDF Online Free Add Digital Signature Instantly
Sign PDF Tool: Add Digital Signature Securely
✍️ Sign PDF — Instant, Secure Digital Signatures
Sign any PDF with your drawn or uploaded signature. Place it precisely on any page — all in your browser. No uploads, no servers, complete privacy.
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🔐 Client‑Side PDF Signing: How It Works & Why It’s Secure
Traditional online signature tools require uploading your PDF to a remote server, exposing sensitive documents and your signature to potential breaches. Our tool performs all operations entirely inside your browser using pdf-lib to embed your signature as an image onto the PDF. Your signature is captured via canvas drawing or an image file — and never leaves your device. The PDF is processed locally, ensuring complete privacy for contracts, agreements, and any confidential document.
You can draw a signature with your mouse or finger, or upload a scanned image. Then choose the page and precise coordinates (in points, 1 point = 1/72 inch). The signature is embedded directly into the PDF’s content stream, making it part of the document. Because everything runs client‑side, you get instant results with zero latency. This approach is fully compliant with GDPR, HIPAA, and corporate security policies, giving you peace of mind when signing important documents.
📘 How to Sign a PDF in 5 Simple Steps
- Upload PDF – Drag & drop your PDF into the zone or click “Browse files”.
- Create signature – Draw using the canvas or upload an image of your signature.
- Choose page & position – Select the page number and enter X, Y coordinates (points from top‑left). You can preview the placement.
- Apply signature – Click “Apply Signature & Download PDF”. A progress bar shows the embedding process.
- Download signed PDF – After completion, click the download button to save your signed document.
No registration, no watermarks, unlimited signatures — all with maximum privacy.
💼 Perfect for Professionals & Everyday Users
Legal Professionals: Sign contracts and agreements without printing. Freelancers: Add your signature to invoices or proposals. Business Teams: Approve internal documents digitally. Students: Sign permission forms or application documents. Remote Workers: Complete official paperwork from home. Because everything happens locally, you can sign sensitive documents without worrying about data leaks.
❓ Advanced Technical FAQ
📌 Is my signature stored or transmitted?
No. Your signature is only used in the current browser session to generate the PDF. It is never stored, uploaded, or transmitted to any server. After you close the page, everything is gone.
⚙️ How is the signature placed on the PDF?
We use pdf-lib to embed your signature as an image onto the PDF page at the exact coordinates you specify. The signature becomes a permanent part of the PDF content.
🛡️ Can I sign multiple pages?
This version adds one signature per operation. To sign multiple pages, simply repeat the process (add the same signature to different pages by clicking “Apply Signature” again).
📏 How do I know where to place the signature?
You can use the “Preview Position” button to see a marker on the PDF preview. Adjust X and Y until it looks correct. Coordinates are measured in points from the top‑left corner of the page.
🖼️ What image formats are accepted for signature upload?
We accept PNG and JPG/JPEG images. The image will be embedded directly; we recommend a transparent background for best results.
🔒 Is this a legally binding signature?
This tool creates a visual signature. For legally binding e-signatures, you may need additional authentication methods. However, it is widely accepted for internal approvals and many business documents.
🌐 What browsers are compatible?
Works on all modern browsers: Chrome, Edge, Firefox, Safari. Requires WebAssembly support (available by default). No plugins needed.
📈 Why does the preview sometimes look different from the final PDF?
The preview is rendered using PDF.js and approximates the final look. The actual PDF generation uses pdf-lib, which may have slight rendering differences. Use the preview as a guide.
