How to Sign a PDF Online

Adding a signature to a PDF used to require printing the document, signing it by hand, then scanning it back into a digital format. Today you can sign any PDF directly online without a printer, scanner, or special software. Our free tool lets you upload your signature as an image and place it precisely on any page of your document.

This is useful for contracts, agreements, permission forms, application letters, and any document that requires a personal signature. The result is a professional, signed PDF that's ready to send.

Step 1 – Prepare Your Signature Image

You'll need a digital image of your signature. The best way to create one is to:

1. Sign your name on a clean white piece of paper using a dark pen.
2. Take a clear photo of it or scan it.
3. Crop the image tightly around the signature so there is minimal white space around it.
4. Save it as a PNG with a transparent background if possible — this gives the most professional result, as the signature blends seamlessly into the document rather than appearing on a white rectangle.

If you don't have a transparent background, a regular JPG or PNG will also work. The signature will appear on a white background, which is still acceptable for most purposes.

Step 2 – Open the Sign PDF Tool

Go to our Sign PDF tool. You will see two upload boxes: one for your PDF document and one for your signature image.

Step 3 – Upload Your PDF and Signature

Upload your PDF document and your signature image. The tool accepts PDFs up to 10MB. Your signature can be in PNG, JPG, or GIF format. After uploading both files, enter the page number where your signature should appear. Click Upload & Continue to generate a preview of that page.

Step 4 – Position and Resize Your Signature

A preview of the selected PDF page will appear with your signature overlaid on it. You can:

• Drag the signature to move it to the correct position — typically over a signature line on the form.
• Drag the red corner handle to resize the signature so it fits naturally within the space.

Take your time with this step. Position the signature exactly where it belongs — ideally aligned with the printed signature line on the document. The preview shows you exactly how the final result will look.

Step 5 – Apply and Download the Signed PDF

When you're happy with the position and size, click Apply Signature. The tool embeds your signature into the PDF at the precise location and size you set. The signed file downloads automatically to your device.

Tips for a Professional-Looking Signature

• PNG with transparent background: This is the gold standard. The signature appears without a background box, blending naturally with the document. Many photo editing apps and online tools can remove the background from a signature image.
• Dark ink on white paper: When photographing your signature, use a black or dark blue pen on clean white paper in good lighting to get the clearest image.
• Crop tightly: Remove as much white space around the signature as possible before uploading. This makes positioning easier and the result looks cleaner.
• Match the size: Resize the signature box on the preview to match the actual size of the signature line on the document. An oversized signature looks unprofessional.
• Check the page number: Make sure you're signing the correct page. Multi-page contracts often have a signature line on the last page.

Common Use Cases for Signing PDFs

Employment contracts: New employees often need to sign offer letters and employment agreements electronically before their start date. Signing a PDF is the standard way to do this.

Lease and rental agreements: Landlords and tenants frequently exchange agreements digitally. A signed PDF provides a professional and legally documented record.

Permission forms and consent documents: Schools, medical practices, and event organisers routinely require signed forms that can be returned by email.

Freelance contracts and invoices: Freelancers and consultants can sign proposals and contracts directly in PDF format for a professional finish.

Frequently Asked Questions

Is a digitally placed signature legally valid?

The legal validity of electronic signatures varies by country and context. An image signature placed on a PDF is generally acceptable for informal agreements and many business contracts. For formal legal, financial, or government documents, check the specific requirements in your jurisdiction. For high-stakes documents, a certified electronic signature service may be required.

What image formats are supported for the signature?

The tool supports PNG, JPG, and GIF. PNG with a transparent background is strongly recommended for the cleanest results.

Can I sign multiple pages?

Currently the tool applies the signature to one page at a time. To sign multiple pages, apply the signature to each page separately by re-uploading the result each time.

Is my document safe?

Yes. Files are processed on a secure server and automatically deleted within 10 minutes. No account is required and no files are stored permanently.

What if the signature doesn't look right?

If you are not happy with the result, simply re-upload the original PDF and try again with a better signature image or a different position.

Related Tools

• Sign PDF – Add your signature now
• Add Text to PDF – Add custom text like a date or name
• Protect PDF – Password-protect your signed document
• Compress PDF – Reduce the file size before sending