The fastest way to add an electronic signature to a PDF is to open it in a free browser-based signing tool, place your signature and any dates or initials where they belong, and download the signed file. No account, no software to install, no printing. Below is how to do that, plus how to do it in Adobe Acrobat Reader or macOS Preview if you'd rather use software you already have.
Option 1: Sign it yourself in your browser (no account)
If you only need to put your own signature on a PDF (rather than send it to someone else to sign), GSD's free sign a PDF tool handles it in the browser with no sign-up:
- Open the tool and upload your PDF. Go to /sign-pdf and drag in the file, or select it from your computer. It works the same way on a phone, tablet, or desktop.
- Add your signature. Type your name in a signature font, draw it with your mouse, finger, or trackpad, or upload an image of your handwritten signature. If you want a reusable signature to save for later, the free signature generator lets you create and download one first.
- Place it on the page. Click where the signature belongs on the PDF, then add a date or your initials on any other pages that need them.
- Download the signed PDF. Save the finished file to your device. It's ready to email, upload to a portal, or print.
That's the whole process, and it costs nothing. You're signing a document yourself, not sending an envelope to other signers, so there's no plan or account involved.
Option 2: Sign a PDF in Adobe Acrobat Reader
If you already have Adobe Acrobat Reader installed, it includes a built-in "Fill & Sign" tool. In general terms, you open the PDF in Acrobat Reader, switch to the Fill & Sign tool, and you'll be able to type, draw, or place an image of your signature onto the page, then save the file. The exact menu labels shift a little between Acrobat versions, so look for a tool named something like "Fill & Sign" or "Sign" in the toolbar or the tools panel. It's a solid option if Acrobat Reader is already part of your workflow, though it's a heavier download than a browser tool if you don't have it yet.
Option 3: Sign a PDF in macOS Preview
On a Mac, the built-in Preview app can also add a signature to a PDF without any extra software. Open the PDF in Preview and look for the markup tools (usually a pen-tip or toolbox icon in the toolbar). You'll find a signature option there. Preview typically lets you create a signature by drawing it with your trackpad or by holding a signed piece of paper up to your Mac's camera. Once it's created, drag it onto the page and save the file. It's a convenient no-install option if you're on a Mac and nobody else needs to sign.
Need to send the PDF for someone else to sign instead?
Everything above is for signing a document yourself. If a client, vendor, employee, or co-signer needs to add their signature, that's a different workflow. You upload the PDF, add each signer's name and email, place fields for them to fill in, and send it out. See how to send a PDF for signature for the full walkthrough, including how to set a signing order and add reminders.
"Digital signature" vs. "electronic signature"
A lot of people looking up how to sign a PDF type "digital signature," and the two terms mean different things. An electronic signature is any electronic indication of intent to sign: typing your name, drawing it, or clicking to accept. That's what GSD's sign-pdf tool and most e-signature platforms provide, backed by a tamper-evident record of who signed and when. A digital signature, technically speaking, is a specific certificate-based cryptographic method (public-key infrastructure) sometimes used to implement an electronic signature. You'll mostly see it in Adobe Acrobat's certificate-signing feature and in some government or regulated workflows. GSD provides electronic signatures with a hashed audit trail, not certificate-based PKI digital signatures. For most everyday contracts, waivers, and agreements, an electronic signature is legally sufficient. If your situation calls for the certificate-based kind, see electronic vs. digital signature for the full comparison.
Does an electronic signature on a PDF hold up legally?
In the United States, the federal ESIGN Act and the state-level Uniform Electronic Transactions Act (UETA) both establish that an electronic signature carries the same legal weight as a handwritten one for most contracts, as long as the signer intended to sign and the record can be retained and reproduced. That's why the record behind the signature matters. A completed document should come with a timestamp, the signer's IP address, and ideally a hash proving the file hasn't changed since signing. For more on when that applies (and the situations where it doesn't), see are electronic signatures legally binding.
Frequently asked questions
Do I need an account to sign a PDF myself?
No. GSD's sign-pdf tool lets you upload a PDF, add your signature, and download the signed file without creating an account or entering payment details. An account only becomes useful once you want to send documents to other people or keep a history of what you've signed.
Can I type my signature instead of drawing it?
Yes. Most browser-based signing tools, including GSD's, let you type your name in a signature-style font, draw it by hand with a mouse, finger, or trackpad, or upload a photo of your handwritten signature. Any of these counts as a valid electronic signature under the ESIGN Act.
Is a typed or drawn signature on a PDF actually legal?
Generally, yes, for most everyday business documents in the US. The ESIGN Act and UETA give electronic signatures the same legal standing as ink signatures for the vast majority of contracts. A small number of document types (like wills or certain court filings) are excluded. See are electronic signatures legally binding for the specifics.
What's the difference between signing a PDF and sending it for signature?
Signing a PDF yourself is a one-person job: you add your own signature and you're done. Sending a PDF for signature means someone else needs to sign it. You upload the document, add their name and email, place the fields they need to fill in, and GSD emails them a secure link to sign in their own browser. See how to send a PDF for signature.
Will the signed PDF look different from a scanned, ink-signed one?
It can look much the same, since your signature appears on the page just as a handwritten one would. The difference is underneath: a properly signed electronic PDF also carries a tamper-evident record, which a scanned paper document doesn't have on its own. That record is what makes the signature easy to verify later if it's ever questioned.