How to Sign Documents Online: The Best E-Signature Tools (Some Free)

DocuSign, Dropbox Sign and the free signing tools already on your computer. When a quick signature is fine and when you need a proper e-signature service.

There are two different jobs hiding behind "I need to sign this online":

Someone sent you a PDF to sign. You just need to add your signature and send it back. That's free and takes a minute.
You need other people to sign your documents, with a record of who signed and when. That's what e-signature services are for.

Job 1: Signing a PDF someone sent you (free)

On a Mac: open the PDF in Preview, click the markup toolbar, then the signature button. Sign on the trackpad or hold paper up to the camera.
On an iPhone or iPad: open the PDF in Files or Mail, tap markup and add your signature.
On Windows: the free Adobe Acrobat Reader includes "Fill & Sign".
Anywhere: many free PDF tools can add a signature. See free PDF editors that don't watermark your files.

For most everyday forms (a lease renewal, a school permission slip, a freelance contract), that's all you need.

Job 2: Getting others to sign your documents

E-signature services send the document to each person in turn, guide them to the right spots, and create an audit trail: a record of email addresses, times and IP addresses that shows who signed what. That trail is what makes the signature easier to rely on if there's ever a dispute.

Dropbox Sign: best free plan

Formerly HelloSign, Dropbox Sign has a free plan for a small number of signature requests a month (around three), which covers occasional needs. Paid plans add templates, team features and more requests.

Pick it if: you send a few contracts a month and want something simple.

DocuSign: the industry standard

DocuSign is what large companies and estate agents usually use, and people recognize it, which helps them trust the email. The Personal plan costs roughly $10 to $11 a month billed yearly, with a limited number of envelopes. There's no free plan for sending, but signing is always free for the people you send to.

Pick it if: you deal with big clients or industries where DocuSign is expected.

Adobe Acrobat Sign

If you already pay for Adobe Acrobat, its signing features may be included. Check your plan before buying another tool.

Are e-signatures legally valid?

In many countries, including the US (under the ESIGN Act) and the EU (under eIDAS), electronic signatures are legally valid for most everyday agreements. Some documents, like certain wills, property deeds or court documents, may still need special formalities.

This isn't legal advice. For anything high-stakes, check with a lawyer in your country.

Quick tips

Use a template for contracts you send often.
Set the signing order when it matters, such as client first, then you.
Download and keep the completed copy with its certificate, separately from the service.
Don't use a picture of your signature on public websites. It's easy to copy.