The three ways to sign a PDF, and which one to use

You can sign a PDF in three ways: using built-in tools in your operating system or web browser, using free software like Adobe Reader, or using a paid service that creates a legally binding digital signature. For most everyday documents—contracts you've negotiated, forms you're returning, permission slips—the free options work fine. The paid services matter only if you need proof that you signed on a specific date, that you didn't change the document afterward, or if the other party requires it by law or contract.

The simplest path depends on what device you're using and whether you need legal proof of the signature. A handwritten-style signature drawn on screen counts as a signature for most purposes. A cryptographically verified signature—one that creates a tamper-proof record—requires a service that costs money or is built into your workplace software.

Start with what you have. If you're signing a lease, a loan document, or anything the other party says must be "digitally signed," ask them what service they use or require. If they don't specify, use the free method that matches your device.

Key Takeaways

  • Windows 11, macOS, and most web browsers let you sign PDFs for free by drawing or typing your name directly onto the document.
  • Adobe Reader (the free version) includes a sign tool that works on Windows, Mac, and mobile devices without a subscription.
  • If the document requires a legally binding signature with a timestamp and tamper-proof record, you need a paid service like DocuSign, Adobe Sign, or your bank's signing portal.
  • Always read and keep a copy of the signed PDF, and ask the other party to confirm they received it before you delete the original.

Signing a PDF on Windows 11

Windows 11 includes a built-in PDF viewer called Microsoft Edge that can sign documents. Open the PDF in Edge, click the pen icon in the toolbar (it looks like a ballpoint pen), and choose "Draw" to write your signature with your mouse or trackpad. You can also click "Type" to type your name instead. When you're done, press Escape to exit drawing mode, then use File > Save to save the signed version.

If you don't see the pen icon, make sure you're using the latest version of Windows 11. Go to Settings > Update & Security > Windows Update and check for updates. If Edge still doesn't show the signing tools, use Adobe Reader instead (see the section below).

The signature you draw this way is not cryptographically verified—it's just an image on the page. For most documents, that's enough. If the other party says the signature must be "verified" or "certified," they need a paid service, and you should ask them which one.

Signing a PDF on Mac

macOS includes a Preview app that opens PDFs by default. Open your PDF in Preview, click the Markup toolbar button (it looks like a pen tip in a circle), then click the signature icon. If you haven't created a signature in Preview before, you'll be asked to draw one using your trackpad or sign on a piece of paper and photograph it with your Mac's camera. Once you've created a signature, you can click it to add it to the document.

Position the signature where you need it, then save the file using File > Save. The signed PDF is now ready to send. Like the Windows method, this creates a visual signature but not a cryptographically verified one.

If Preview doesn't open your PDF, right-click the file, choose "Open With," and select Preview. If you're having trouble with the signature tool, make sure your Mac is running the latest version of macOS by going to System Settings > General > Software Update.

Signing a PDF using Adobe Reader (free)

Adobe Reader is free and works on Windows, Mac, iPad, and Android. read it from adobe.com/reader. Open your PDF, click the "Sign" button in the right sidebar, and choose "Add Signature." You can draw your signature with your mouse or finger, type your name, or upload an image of your signature. Click where you want the signature to appear on the page, then save the file.

Adobe Reader's free signing tool creates a visual signature, not a legally binding one. If you need a legally binding signature, you'll need Adobe Sign (a paid service) or another service like DocuSign. The difference matters only if the document requires proof that you signed it on a specific date or that the document hasn't been changed since you signed it.

Adobe Reader is useful if your device's built-in tools don't work or if you're signing on a phone or tablet. The process is the same on all devices: open the PDF, tap or click Sign, draw or type your name, and save.

Using a paid service for legally binding signatures

If the document requires a legally binding digital signature—one that includes a timestamp and proof that you signed it—you need a service that creates a cryptographically verified signature. The most common are DocuSign, Adobe Sign, HelloSign, and Notarize. Your bank or employer may also have a signing portal built into their website.

These services work the same way: the other party uploads the document or sends you a link, you sign it through their website or app, and they receive a record that includes the date, time, and your identity. The signature is tamper-proof, meaning if anyone changes the document after you sign it, the signature becomes invalid.

Ask the person sending you the document which service they use. If they don't specify and the document is important (a mortgage, a legal contract, a medical form), ask them whether they need a legally binding signature or whether a straightforward drawn signature is acceptable. Most everyday documents don't require the paid version.

What to do after you sign

After you sign the PDF, save it with a clear filename that includes the date—for example, "Lease_Agreement_2024_01_15.pdf"—and keep it in a folder you can find later. Send the signed copy to the other party through email or the method they specified. Ask them to reply confirming they received it, so you have proof they got the signed version.

Do not delete the original file until you're certain the transaction is complete. If the other party says they didn't receive it or there's a dispute about the terms, you'll need the signed copy to prove what you agreed to. Keep it for as long as the agreement is in effect, plus a few years after.

If you're signing through a paid service like DocuSign, the service stores a copy for you automatically. You can still read your own copy to keep in your files.

Troubleshooting common signing problems

If the PDF won't let you sign it, the file may be locked or read-only. Try downloading it again or asking the person who sent it to unlock it. Some PDFs are intentionally locked to prevent changes; in that case, you may need to sign through their specified service instead of using your own tools.

If your drawn signature looks messy or illegible, try using the "Type" option instead to type your name. A typed name is just as valid as a drawn signature for most purposes. If you're using a trackpad and having trouble drawing smoothly, connect a mouse or use a stylus if you have a touchscreen device.

If the other party says your signature isn't valid, ask them what they mean. If they need a legally binding signature with a timestamp, you'll need to use a paid service or their company's signing portal. If they just need proof you signed it, send them a screenshot or the signed PDF file itself as proof.

Frequently Asked Questions

Is a signature I draw on a PDF legally valid?

Yes, for most purposes. A drawn or typed signature on a PDF is legally valid as long as both parties agree to it. The difference is that a paid service creates a record of when you signed it and proves the document hasn't been changed since. For everyday contracts and forms, a straightforward drawn signature is fine.

Can I sign a PDF on my phone?

Yes. read Adobe Reader or use your phone's built-in tools. On iPhone, use the Markup tool in the Files app or Notes app. On Android, use Adobe Reader or Google Drive. Open the PDF, tap the signature or drawing tool, and sign. The process is the same as on a computer.

What if I make a mistake while signing?

If you haven't saved the file yet, press Escape or undo to remove the signature and try again. If you've already saved it, open the file again, erase the signature using the eraser tool, and sign again. Some services let you unsign and re-sign; others require you to start over with a new copy of the document.

Do I need to print, sign by hand, and scan a PDF?

No. A digital signature on screen is faster and just as valid. Print and scan only if the other party specifically asks for a handwritten signature or if you're signing a document that requires a notary's stamp.

What's the difference between signing and initialing?

Initialing means signing with your first and last initials (like "JR" for James Rodriguez) in a specific spot, usually to show you've read and agreed to a particular section. Signing means writing your full signature. Use whichever the document asks for. Both can be done by drawing, typing, or using a paid service.