How to Sign a PDF Document on Your Computer or Phone

The simplest way to sign a PDF depends on what you already have

If you have Adobe Acrobat Reader (the free version), you can sign a PDF directly in that program without installing anything else. Open the PDF, click the "Sign" button in the toolbar, draw or type your signature, and save. If you use Microsoft Word or Google Docs, you can also insert a signature line into a PDF before you send it to someone else. For phone users, most PDF apps built into iOS and Android let you add a signature by drawing on the screen.

The method you choose depends on three things: whether you need to sign a PDF someone sent you, or create one for others to sign; whether you want a typed signature, a drawn one, or an image of your handwritten signature; and whether you're working on a computer or a phone. None of these routes requires paying for software or uploading your document to a website you don't trust.

Key Takeaways

• Adobe Acrobat Reader's free version lets you sign PDFs you receive and save them without uploading to the internet.
• You can create a signature once (drawn, typed, or from an image) and reuse it across multiple documents.
• If you need someone else to sign a document, Microsoft Word and Google Docs let you add signature fields before converting to PDF.
• Phone users can sign PDFs using the built-in markup tools in iOS Files or Android's native PDF reader without downloading an app.
• A signature added in these programs is not legally binding in the same way a handwritten signature is — the document itself determines what counts.

Signing a PDF you received using Adobe Acrobat Reader

read Adobe Acrobat Reader from adobe.com if you don't have it. It's free and works on Windows, Mac, and Chromebooks. Open the PDF in Acrobat Reader, then look for the "Sign" button in the toolbar on the right side of the screen.

Click "Sign," then choose "Add Signature." You'll see three options: draw your signature with your mouse or trackpad, type your name in a signature font, or upload an image of your handwritten signature. Pick whichever feels most natural. If you draw or type, the program will save that signature and let you reuse it on future PDFs without redrawing it each time.

Once you've created your signature, click where on the PDF you want it to appear. The signature will be placed at that spot. Then save the file — use "File" then "Save" or press Ctrl+S (Windows) or Command+S (Mac). The signed PDF stays on your computer. You can now email it, print it, or store it wherever you normally keep documents.

Creating a PDF with signature fields for someone else to sign

If you're the one sending a document to someone else to sign, you can add empty signature fields in Microsoft Word or Google Docs before you convert it to PDF. This tells the other person exactly where to sign and makes the document look professional.

In Microsoft Word, go to the "Insert" tab, click "Signature Line," and fill in the fields for the signer's name and title if you want. Place as many signature lines as you need. Then save the file as a PDF: go to "File," click "Save As," and choose PDF from the file type dropdown. Send that PDF to the person who needs to sign it. They can open it in Acrobat Reader and use the "Sign" button to add their signature in the space you created.

In Google Docs, the process is similar but slightly different. Click "Insert," then "Drawing," then draw a line or box where you want the signature to go. Add text above it that says "Sign here" or the signer's name. When you're done, read the document as a PDF and send it. The recipient can sign it using Acrobat Reader or their phone's PDF app.

Signing a PDF on your phone

On an iPhone or iPad, open the PDF in the Files app or in Mail (if someone sent it to you). Tap "Markup" (the pen-in-a-circle icon), then tap the plus sign and choose "Signature." Draw your signature on the screen with your finger, then tap "Done." The signature appears on the PDF. Tap "Save" or "Done" again to keep the changes.

On Android, open the PDF in Google Drive or your phone's built-in Files app. Look for a pencil or markup icon, tap it, and select the drawing tool. Draw your signature directly on the document. When you're finished, save the file. Some Android phones also have a dedicated PDF app (like Google PDF Viewer) that includes a signature tool in the markup menu.

Phone signatures work the same way as computer signatures — they're saved as part of the PDF file and stay with the document when you email it or upload it somewhere.

Using an image of your handwritten signature

If you prefer to use a real handwritten signature rather than drawing one on screen, you can photograph or scan your signature and upload it as an image. Write your name on a piece of white paper with a dark pen, take a photo of it with your phone or scan it, and save it as a JPG or PNG file on your computer.

In Adobe Acrobat Reader, when you click "Add Signature," choose the image option and select the file you saved. The program will crop out the white background and show just your signature. You can now use this image signature on any PDF going forward — it will look identical each time.

This method is useful if you sign many documents and want consistency, or if you find drawing on a screen awkward. The image signature is treated the same way as a drawn or typed one by the program.

What happens after you sign — sending and storing the document

Once you've signed a PDF, it's a regular file on your computer or phone. You can email it, upload it to a website, print it, or store it in a folder. The signature stays part of the document and doesn't disappear or change.

If you're sending a signed document to someone, use your normal email or file-sharing method — you don't need a special service. If the document is sensitive (financial records, medical forms, legal papers), consider whether you trust the email or service you're using to keep it private. A signature on a PDF doesn't encrypt the document or hide its contents; it just shows that you signed it.

Keep a copy of any signed document for your own records. If you signed a contract, a rental agreement, or a form for a government agency, save that PDF in a folder you can find later. Many people create a "Signed Documents" folder on their computer or in cloud storage like Google Drive or OneDrive.

When a PDF signature is not legally binding

A signature added to a PDF using these methods is not automatically legally binding. Whether it counts depends on the document itself and the laws in your state or country. A contract signed in Adobe Acrobat Reader is usually treated the same as one signed with a pen — both show intent to agree. A form for a government agency might require a handwritten signature or a notarized signature, in which case a PDF signature won't work.

Before you sign an important document (a lease, a loan, a legal agreement), check whether the other party will accept a digital signature. Ask them directly: "Can I sign this PDF and email it back?" If they say yes, you're fine. If they say no or ask for a notarized signature, you'll need to print it, sign it by hand, and either mail it or use a notary service.

Frequently Asked Questions

Can I sign a PDF on my phone and email it right away?

Yes. Sign it using your phone's markup tools or a PDF app, save the changes, and email it when ready. The signature is part of the file and travels with it. No special steps needed.

What if I want to sign a PDF but keep my signature private?

Your signature is visible on the PDF itself — anyone who opens the file can see it. If you're concerned about privacy, check what information the document contains and whether you trust the person or organization receiving it. A signature doesn't hide the document's contents.

Do I need to upload my PDF to a website to sign it?

No. Adobe Acrobat Reader, Microsoft Word, Google Docs, and your phone's built-in tools all let you sign without uploading anywhere. Only use a website if the other party specifically asks you to, and check that it's a service you recognize.

Can I reuse the same signature on multiple documents?

Yes. Once you create a signature in Adobe Acrobat Reader (drawn, typed, or from an image), the program saves it. The next time you sign a PDF, you can click "Add Signature" and select the saved one instead of creating a new one.

What's the difference between signing a PDF and signing a document in Word?

A PDF is a finished document — once you sign it, the signature is locked in place and the document looks the same to everyone who opens it. A Word document can be edited, so a signature in Word is less find. For important documents, convert to PDF first, then sign.