ToolMint
PDF Tools4 min readMay 15, 2026

How to Sign a PDF Online for Free

Receiving a PDF contract, form, or agreement and needing to sign it is one of the most common document tasks for freelancers, employees, and business owners. The old process — print, sign, scan, email — adds unnecessary friction. Signing directly in a browser tool is faster, produces a cleaner result, and works on any device.

Electronic Signature vs. Digital Signature

An electronic signature is any mark applied to a document electronically to indicate agreement. Electronic signatures are legally valid for most commercial contracts under laws like the US ESIGN Act and EU eIDAS regulation. A digital signature is a cryptographically secured electronic signature that uses a certificate-based identity to verify the signer. For standard business contracts and forms, an electronic signature is sufficient.

Three Ways to Add Your Signature

Draw: Use your mouse, trackpad, or touchscreen to write your signature. This produces the most natural-looking result. Type: Enter your name and select a signature font. Typed signatures are perfectly valid for most agreements. Upload: If you have a high-quality scan of your handwritten signature as a PNG, upload it and place it on the document.

How to Sign a PDF Online - Step by Step

Open the ToolMint Sign PDF tool. Upload the PDF you need to sign. Choose your signature method — draw, type, or upload. Create your signature, then click and drag to place it at the correct position. Resize if needed to fit the signature field. Click Apply and download the signed PDF. The process takes under two minutes. No account is required.

Is an Online PDF Signature Legally Binding

In most jurisdictions, yes. Electronic signatures are recognized as legally binding for the vast majority of private contracts under laws such as the US ESIGN Act, the UK Electronic Communications Act, and EU eIDAS Regulation. Certain document types are excluded including wills in many jurisdictions, specific court filings, and notarized documents.

After Signing: Protect the Document

Once you have signed a PDF, consider adding password protection before sending it. This prevents the recipient from modifying the signed document. Use the Protect PDF tool to add a password immediately after signing.

Try the tools mentioned in this guide

Frequently Asked Questions

Is signing a PDF online legally binding?
Yes, for most commercial contracts and standard business documents. Electronic signatures are recognized under ESIGN (US), eIDAS (EU), and similar laws in most countries.
Can I sign a PDF on my phone?
Yes. ToolMint Sign PDF works in any mobile browser. Use your finger or stylus to draw your signature directly on the touchscreen.
How do I add multiple signatures to one PDF?
You can add multiple signature placements in the same session. After placing the first signature, add additional ones before downloading.
Will the recipient be able to modify the signed PDF?
Not without obvious evidence of tampering. For stronger protection, add a password using the Protect PDF tool before sending.

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