Sign PDF Online

Add text, drawn, or uploaded image signatures to your PDF documents 100% locally in your browser for free.

Upload your PDF document

Drag & drop your PDF file here, or click to browse

100% client-side — your document never leaves your device
🔒 Processes locally in your browser — zero files are uploaded to our servers.

How the Free Online PDF Signer Works

The Sign PDF Online tool by DwellixTools is a client-side document utility that allows you to add custom signatures directly onto your PDF files without uploading them to any external servers.

Many online PDF signers require you to upload your sensitive legal documents, contracts, or tax forms to their cloud storage. This tool operates differently:

  1. Local Preview Rendering: We use Mozilla’s PDF.js rendering engine to draw your PDF pages directly on an HTML5 canvas in your browser.
  2. Interactive Signature Overlay: A draggable and resizable signature container is placed on top of the document preview canvas. You position it exactly where you need your signature to go.
  3. Local PDF Modification: When you click Apply & Download, the pdf-lib library modifies the document’s binary data locally on your computer, embedding your signature image at the exact page and scaled coordinates you selected.

Key Features

  • ✍️ Draw Signature: Draw your signature naturally on a canvas pad using a mouse, trackpad, or touchscreen (fully optimized for mobile tap and drag targets).
  • 🔤 Type Cursive Style: Type your name and select from multiple elegant cursive handwriting fonts to generate a professional-looking digital signature.
  • 📷 Upload & Auto-Clean Scanned Signature: Upload an existing image of your handwritten signature. The tool automatically removes white or light background paper pixels using a client-side luma filter, rendering a clean transparent signature that blends perfectly onto the page text.
  • 🎨 Ink Color Customization: Choose between Black, Dark Blue, and Red ink colors to match your document’s requirements.
  • 📄 Place Multiple Signatures Across Pages: Place multiple signatures on the same page or spread them across different pages. Use the navigation buttons to move between pages and add new signatures as needed.
  • 🔒 Local Browser-Only Processing: All operations run locally. No files, signatures, or documents are uploaded to our server or third-party APIs. Your data remains entirely private on your device.

How to Sign a PDF Document

  1. Upload Your PDF: Drag and drop your PDF file into the upload zone, or click to browse and select it.
  2. Create Your Signature:
    • Draw: Draw your signature on the pad. Select your ink color (Black, Blue, Red).
    • Type: Click the “Type” tab, type your name, and select a cursive handwriting font.
    • Upload: Click the “Upload” tab and choose a signature image from your computer.
  3. Add to Document: Click the Add to Document button. The signature overlay block will appear on the PDF page.
  4. Position and Resize:
    • Drag the dashed signature box to the line where you want to sign.
    • Drag the small blue handle on the bottom-right corner of the box to resize the signature so it fits the line perfectly.
    • Use the Prev and Next page controls if you need to place the signature on a different page.
  5. Apply & Download: Click the Apply & Download button in the top right. The browser will compile the signature into your PDF and trigger an immediate file download of the signed document.

Frequently Asked Questions (FAQ)

Are my PDF files or signatures uploaded to your server?

No. All PDF rendering, signature creation, coordinate transformations, and final PDF compilation are executed directly on your device using JavaScript. No documents, files, signatures, or personal data are ever uploaded, sent, or stored on our servers.

Can I verify that no data is transmitted?

Yes. You can open your browser’s Developer Tools (press F12 or Ctrl+Shift+I), select the Network tab, and drag a PDF in. You will see that no network requests are initiated when uploading, signing, or downloading the document.

Is a digitally signed PDF legally binding?

Yes, in many jurisdictions (such as the US ESIGN Act and the European Union eIDAS regulations), electronic signatures on documents are legally recognized. However, this tool provides a basic electronic signature overlay. For high-security, cryptographically-sealed digital signatures or PKI-based certificates, specialized corporate signing platforms are typically required. We recommend verifying specific legal requirements in your jurisdiction.

Can I sign password-protected PDFs?

Yes. If your PDF is locked or encrypted, the tool will securely prompt you to enter the password directly in your browser. The decryption is processed entirely locally on your device to ensure maximum privacy.

Can I sign interactive forms or dynamic PDF layouts?

Yes. The tool flattens all interactive fields (text boxes, drop-downs, and dynamic scripting templates) during compilation. This merges form inputs and signatures into a standardized static layer, making the output PDF 100% compatible with all readers, browsers, and print services.

Is there a file size limit for uploads?

There is no hard limit on the file size. However, because all computations happen locally in your web browser, very large files (above 20MB) may take a few seconds to compile and download. The tool will display a size warning banner for larger files to notify you.

Can I place multiple signatures on different pages?

Yes. You can add as many signatures as you need. Each time you click “Add to Document”, a new signature box is created. You can drag, resize, and delete them individually. If you navigate to other pages, you can add more signatures to those pages as well. When you click Apply & Download, the tool will compile all placed signatures across all pages into the final PDF in a single download.