Sign PDF Online Free – Add Electronic Signature to Any PDF

Draw, type, or upload your signature and place it precisely on any PDF. Legally valid electronic signature recognized in most countries. Free, no account required.

Select a PDF to sign

Drag & drop your PDF file here

PDF files only · Processed securely · Never stored

How it works

Sign a PDF in 3 steps

No sign-up required for basic signing. Works on any modern browser - desktop, tablet or mobile.

01

Upload your PDF

Drop or select any PDF file. SupaPDF renders it instantly in your browser - no software install, no plugin needed.

02

Add your signature

Draw, type, or upload your signature image. Drag it to the exact position on the document you need to sign.

03

Sign & Download

Click "Sign & Download" and your signature is permanently embedded into the PDF using server-side processing for maximum compatibility.

Why SupaPDF

Everything you need to sign PDFs

Three signature types

Draw freehand, type your name in a script font, or upload an image of your handwritten signature.

Multi-party signing

Send documents to multiple signers via email magic links. Recipients don't need an account to sign.

Private & secure

All uploads use HTTPS encryption. Files are permanently deleted from our servers after download.

Advanced eSignature

Enable SMS OTP verification for legally-binding AES signatures. Full audit trail included.

Developer API

Sign PDFs programmatically

Use the sign_pdf operation to embed signatures into PDFs inside your own application or workflow.

curl -X POST https://api.supapdf.com/v1/jobs \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "tag": "sign-pdf",
    "tasks": {
      "import": { "operation": "import/url", "url": "https://example.com/document.pdf" },
      "sign": {
        "operation": "sign_pdf",
        "input": ["import"],
        "fields": [
          { "type": "signature", "page": 1, "x": 50, "y": 80, "width": 200, "height": 80, "content": "data:image/png;base64,..." }
        ]
      },
      "export": { "operation": "export/url", "input": ["sign"] }
    }
  }'

FAQ

Frequently asked questions

Everything you need to know about signing PDFs with SupaPDF.

Ready to sign your PDF?

Free to use · No account required · Instant download