How to Sign a PDF Document (Free, on Any Device)

To sign a PDF, open it in free software you already have. Adobe Acrobat Reader's Fill & Sign on Windows or Mac, Preview on a Mac, or Microsoft Edge on Windows. Click the sign tool, draw or type your signature, drag it into place, and save. No printing, no scanning.

What is the fastest way to sign a PDF document?

The fastest tool is the one already on your computer. On a Mac that is Preview. On Windows it is Adobe Acrobat Reader's Fill & Sign or Microsoft Edge. All of them are free, work offline, and take under a minute once you have a signature saved.

That handles the typing-your-name-on-the-line part. It does nothing about what comes after: getting the signed document to the other side, knowing they actually opened it, and stopping it from being forwarded. That is a sharing problem, and we get to it lower down.

Below are step-by-step methods for every platform, the difference between an e-signature and a wet signature, the real limits of any signing tool, and how to share and track a signed PDF (with an NDA gate) once the ink is dry.

How to sign a PDF in Adobe Acrobat Reader (Fill & Sign)

Adobe Acrobat Reader is free on Windows and Mac, and its Fill & Sign tool is the most widely supported way to sign a PDF.

1. Open the PDF in Adobe Acrobat Reader (download it free from Adobe if you do not have it).
2. In the right-hand toolbar or the top menu, click Fill & Sign.
3. Click the Sign icon (a fountain-pen nib), then Add signature.
4. Choose Type to set your name in a script font, Draw to sign with your mouse or trackpad, or Image to upload a photo of your handwritten signature.
5. Click Apply, then click the spot on the page where the signature should go and drag to size it.
6. Save the file: File then Save (or Save As to keep the original unsigned copy).

Fill & Sign also lets you add the date and type into form fields, which is handy for contracts that need both a signature and a printed name.

How to sign a PDF on a Mac with Preview

Preview ships with macOS, so Mac users install nothing.

1. Open the PDF in Preview (double-click it, or right-click then Open With then Preview).
2. Click the Markup icon (the pen tip) in the toolbar to show the markup tools.
3. Click the Sign icon, then Create Signature.
4. Build your signature one of two ways. Trackpad lets you sign with your finger. Camera lets you hold a signature written on white paper up to the webcam and Preview captures it.
5. Click the saved signature to drop it onto the page, then drag and resize it into position.
6. Save with File then Save, or use Cmd+S.

Once you create a signature in Preview, macOS keeps it for next time, so future PDFs take seconds.

How to sign a PDF on Windows with Microsoft Edge

On Windows, if you would rather not install Acrobat, Microsoft Edge can sign PDFs natively because it doubles as a PDF reader.

1. Right-click the PDF, choose Open with, then Microsoft Edge.
2. In the Edge PDF toolbar at the top, click the Draw tool (a squiggly pen line).
3. Pick a color and thickness, then draw your signature directly on the signature line with your mouse, trackpad, or touchscreen.
4. Click the Save icon in the toolbar, or press Ctrl+S, to save the signed PDF.

Edge gives you a drawn, freehand signature only. No saved-signature reuse, no typed option. For a one-off that is fine. For anything you sign often, Acrobat Reader is smoother.

How to sign a PDF with a free online signer

On a borrowed computer or a Chromebook, a browser-based signer works with nothing to install. Solid free options include Smallpdf, Dropbox Sign (formerly HelloSign), DocuSign's free tier, and Adobe's online Fill & Sign.

The flow is roughly the same across all of them:

1. Go to the tool's site and upload your PDF.
2. Drag a signature field onto the page.
3. Type, draw, or upload your signature.
4. Apply it and download the signed PDF.

One caution. An online signer uploads your document to a third-party server before it is signed. Fine for a low-stakes form. Think twice before you upload a term sheet, an employment contract, or anything with personal data. For sensitive documents, sign locally with Acrobat Reader, Preview, or Edge instead.

How to sign a PDF in Google Docs (workaround)

Google Docs has no native PDF e-signature, but you can sign with the built-in Drawing tool.

1. Upload the PDF to Google Drive, then open it with Google Docs (Drive converts it to an editable document).
2. Click Insert, then Drawing, then + New.
3. Use the Scribble line tool (under the Line menu) to draw your signature.
4. Click Save and Close, then drag the signature into position.
5. Export with File, then Download, then PDF Document.

This one is a real workaround. The conversion can shuffle the formatting of the original PDF, so it suits a simple one-page document far more than a multi-page contract.

E-signature vs wet signature: what is legally valid?

A wet signature is the old way: print, sign with a pen, then scan or photograph the page. An e-signature is any electronic mark you apply on screen, whether a typed name, a drawn squiggle, or an uploaded image of your handwritten signature.

For most business documents, an e-signature is legally valid. In the US the ESIGN Act and UETA give electronic signatures the same legal standing as ink. The EU's eIDAS regulation does the same across Europe. A signature you add in Acrobat Reader, Preview, or DocuSign holds up for NDAs, employment offers, vendor agreements, and most commercial contracts.

A few document types still commonly require a wet signature or a notary, such as wills, certain real-estate deeds, and some court filings. For a high-stakes legal document, check the requirement for that specific document and jurisdiction.

There is also a gap between a simple e-signature (a drawn or typed mark) and a digital signature, which is cryptographically bound to a certificate that proves who signed and that the file was not altered afterward. For everyday contracts, a simple e-signature does the job. When you need provable, tamper-evident identity, use a tool that offers certificate-based digital signatures.

The limits of signing a PDF

Signing solves one narrow problem: putting your mark on the page. It does nothing about everything that happens after you hit send, and that is usually where the real risk lives.

• No tracking. Once you email the signed PDF, you are blind. You cannot tell whether the other side opened it, when, or whether they read past page one.
• No control after sending. The recipient can forward the signed file to anyone. There is no way to revoke access or set it to expire.
• No NDA gate. If the document is confidential, signing it does not stop the person you sent it to from passing it on. There is no way to require an NDA before they can view it.
• No version control over the link. Send a signed PDF as an attachment and that exact file is out there forever. Fix a typo and you have to resend, with no way to know who is looking at the old copy.
• Password sharing is its own leak. Encrypt the PDF and you still have to send the password somewhere, usually in the same email thread, which protects nothing.

For a delivery slip or a school form, none of that matters. For a signed NDA, an employment contract, or a fundraising document, you need control that survives after the file leaves your outbox.

Where Plox fits: share and track the signed PDF, with an NDA gate

Signing is step one. What follows is sending the signed document securely, knowing it was actually read, and keeping confidential files from being forwarded. That is where Plox comes in.

Plox is a secure document sharing and virtual data room platform for founders, investors and dealmakers. You sign the PDF in Acrobat, Preview, or your e-signature tool of choice, then upload the signed file to Plox and share it as a trackable link instead of an attachment.

• One-click NDA can gate the link, so a viewer must accept your non-disclosure agreement before they ever see the document. No back-and-forth, no separate signing flow.
• Page-by-page analytics show you who opened the signed document, how long they spent on each page, and whether they finished, with a real-time notification the moment someone views it.
• Passcodes, email verification, and link expiry decide exactly who gets in and for how long, and one-click revoke kills access the instant a deal dies or a person leaves.
• Per-viewer dynamic watermarking stamps every page with the viewer's email, so any leaked screenshot of your signed contract points straight back to the source.
• The link never changes. If you re-sign or correct a document, swap the file behind the same link and everyone sees the current version.

Plox has a genuine free plan: secure links, page-by-page analytics, and real-time view notifications, with no credit card and no time limit. Watermarking, the one-click NDA, and data rooms are on the paid plans, which start at $24/mo for Pro (see /pricing for current numbers).

For the full set of access controls in one place, see how Plox document control handles passcodes, expiry, NDA, and download permissions, and how the one-click NDA gates a link before anyone can read it.

Frequently asked questions

How do I sign a PDF for free?

Use software you already have. On a Mac, open the PDF in Preview, click the Markup then Sign icon, and create a signature with the trackpad or camera. On Windows, use Adobe Acrobat Reader's free Fill & Sign tool or draw a signature in Microsoft Edge. All three are free and work offline, so nothing is uploaded to a third-party server.

Is an electronic signature on a PDF legally binding?

For most business documents, yes. The US ESIGN Act and UETA, and the EU's eIDAS regulation, give electronic signatures the same legal standing as a handwritten one. That covers NDAs, employment offers, and most commercial contracts. A small set of documents, such as wills and certain deeds, may still require a wet signature or a notary, so check the rule for that specific document and jurisdiction.

What is the difference between an e-signature and a digital signature?

An e-signature is any electronic mark you add to a document, like a drawn or typed name. A digital signature is a specific type that is cryptographically bound to a certificate, proving who signed and that the file has not been altered since. For everyday contracts a simple e-signature is enough. For documents needing provable, tamper-evident identity, use a certificate-based digital signature.

How do I sign a PDF without printing it?

You never need to print. Open the PDF in Preview (Mac), Acrobat Reader Fill & Sign (Windows or Mac), or Microsoft Edge (Windows), then draw, type, or upload your signature and drop it onto the page. Save the file and it is signed digitally, with no printer or scanner involved.

Can I track who opens a signed PDF after I send it?

Not if you send it as an email attachment. Once it leaves your outbox you are blind. To see who opened a signed document, when, and how far they read, share it as a tracked link instead. Tools built for this, like Plox, give you page-by-page document control and analytics with real-time notifications, plus per-viewer watermarks so any leak is traceable.

How do I require someone to sign an NDA before viewing my document?

A signed PDF on its own cannot enforce confidentiality. Share the file through a link that requires the viewer to accept a non-disclosure agreement first. Plox's one-click NDA puts that gate in front of the document, so nobody sees the contents until they have agreed, with no separate signing workflow to manage.

Want control that does not end when the file leaves your machine? Share securely with Plox for free: secure links, analytics, and real-time notifications, no credit card required.

For related reading, see what an NDA is and when you need one, and learn how Plox document control keeps a signed document tracked, watermarked, and revocable.