Upload a PDF to Start
Sign documents securely in your browser.
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Step-by-Step Guide: How to Sign PDF
1. Upload Your PDF
Click the “Upload PDF” button or drag and drop your file into the workspace.
The document is rendered instantly. If your PDF contains multiple pages, use the Next / Previous controls in the toolbar to navigate to the page that needs a signature.
2. Add Your Signature
Click “Add Signature” to open the signature panel.
Draw Mode:
Use your mouse, trackpad, finger, or stylus to draw your signature naturally. You can customize line thickness and color, and clear the pad at any time.Upload Image Mode:
Upload a PNG image of your handwritten signature or company stamp. Rotation controls allow precise alignment.
3. Place and Adjust
Once applied, your signature appears as an overlay on the document.
Drag the signature to position it exactly where needed
Resize using the size slider without quality loss
Optional grid mode helps with accurate placement
4. Finalize and Download
After confirming the position, click “Download”.
SignPro mathematically merges the signature into the PDF and instantly downloads a signed file (for example: signed_doc.pdf). The signature is permanent and embedded directly into the document.
You can also sue other tools in market to sign you pdf.
🧰 About This Tool
SignPro is a modern, privacy-first tool that allows you to sign PDF online without installing heavy software or uploading sensitive documents to external servers. It is designed as a true browser-based signing solution for users who value security, performance, and control.
Unlike traditional PDF signing tools, SignPro works entirely client-side. When you upload a PDF contract, invoice, or legal document to sign to PDF, the file is processed locally within your browser using advanced libraries such as PDF.js and PDF-Lib. Your document never leaves your device, ensuring complete privacy and zero server-side storage.
SignPro combines desktop-class precision with web accessibility. The responsive signing canvas adapts seamlessly to mouse, trackpad, stylus, and touch input, making it ideal for signing documents on desktops, tablets, and smartphones. Advanced controls allow you to adjust signature size, color and line weight for perfect placement.
Unlike basic image overlay tools, SignPro permanently embeds the signature into the PDF’s binary structure. The exported file is a flattened, legitimate PDF, meaning the signature cannot be easily moved, edited, or removed by the recipient.
Whether you are signing an NDA, approving an invoice, or submitting an academic document, SignPro provides a fast, secure, and completely free way to sign to PDF directly in your browser.
No. SignPro works entirely client-side. Your PDF is processed locally in your browser using JavaScript. No files are uploaded, stored, or tracked.
Yes. SignPro is fully responsive and supports touch input. You can sign to PDF using your finger or a stylus on smartphones and tablets.
No. Once downloaded, the signature is permanently embedded into the PDF. This ensures document integrity and prevents tampering.
SignPro is purpose-built for signing PDFs, not full document editing. Editing existing text requires a dedicated PDF editor. This tool focuses on secure signature and image placement only.