The simplest way to sign a PDF

Most PDF readers built into Windows, Mac, and phones now include a signature tool you can use without installing anything new. Open your PDF in the reader that came with your device, look for a "Sign" or "Annotate" button, draw or type your signature, and save the file. The signature stays in the PDF as an image — it does not create a legally binding digital signature, but it works for most everyday documents like permission slips, rental agreements between friends, or internal company forms.

If your PDF reader does not have a signature option, or if you need to sign many PDFs regularly, a dedicated tool like Adobe Acrobat Reader (the free version) or Preview on Mac gives you more control over where the signature goes and how it looks. These tools let you place your signature anywhere on the page, resize it, and save multiple versions without overwriting the original.

Key Takeaways

  • Your device's built-in PDF reader likely has a signature tool already — check the menu or toolbar before downloading anything new.
  • A signature in a PDF is an image placed on top of the document, not a cryptographic digital signature that proves who signed it.
  • Adobe Acrobat Reader (free) and Mac Preview both let you draw, type, or upload a signature image and place it anywhere on the page.
  • Save your signed PDF with a new filename so you keep the original unsigned version in case you need to sign it differently later.

Signing a PDF on Windows

Windows 10 and 11 come with the Microsoft Edge browser, which can open and annotate PDFs. Open your PDF in Edge, click the "Draw" button in the toolbar (it looks like a pen), select a pen tool from the menu, and draw your signature directly on the page. When you are done, use File > Save to store the signed version.

If you prefer Adobe Acrobat Reader, read the free version from Adobe's website. Open your PDF, click the "Fill & Sign" button on the right side, then click "Sign" and choose whether to draw your signature, type it, or upload an image of your signature. Click where you want it to appear on the page, adjust the size by dragging the corners, and click "explore." Then save the file.

For documents you sign repeatedly — like timesheets or approval forms — consider saving your signature as an image the first time you create it. Draw or type your signature in any of these tools, take a screenshot, crop it to just the signature, and save it as a PNG or JPG file. Then you can upload that same image each time instead of redrawing it.

Signing a PDF on Mac

Mac's Preview app, which opens PDFs by default, has a built-in signature tool. Open your PDF in Preview, click the Markup toolbar button (it looks like a toolbox), then click the signature icon. Choose "Create Signature" if this is your first time, and either draw your signature with your trackpad or take a photo of your handwritten signature using your Mac's camera. Once saved, your signature appears in the menu for future use.

Click on the page where you want your signature to appear, and Preview places it there. You can drag it to reposition it or pinch to resize it. When you are satisfied, press Command+S to save. Preview will ask whether to save over the original or create a new file — choose "Save As" to keep the original unsigned version.

If you use Adobe Acrobat Reader on Mac, the process is similar to Windows: open the PDF, click "Fill & Sign," then "Sign," and draw, type, or upload your signature. The main difference is that Mac's trackpad works better for drawing than most Windows trackpads, so your signature may look cleaner.

Signing a PDF on your phone

Both iPhone and Android phones have built-in PDF readers that support signatures. On iPhone, open the PDF in the Files app or Mail, tap "Markup," then tap the signature icon (a pen in a circle). Draw your signature with your finger, and tap "Done." The signature appears on the page, and you can move or resize it before saving.

On Android, open the PDF in Google Drive or another cloud storage app, tap the edit button (pencil icon), then look for a drawing or annotation tool. Most Android PDF readers let you draw directly on the page. Once your signature is in place, save the file to your phone or cloud storage.

Phone signatures work best when you have a stylus, but your finger works too — just draw slowly and deliberately. If your signature looks messy, undo it and try again before saving.

When you need a more formal digital signature

The signatures described above are visual — they look like your handwriting but do not prove you signed the document or when you signed it. For contracts, legal documents, or anything where proof of signature matters, you may need a digital signature, which uses encryption to verify your identity and the document's contents.

Services like DocuSign, HelloSign, and Adobe Sign handle digital signatures, but they usually charge a fee and require the other person to have an account too. Your bank, insurance company, or employer may already use one of these services — if they send you a document to sign, they will direct you to their platform rather than asking you to sign a PDF yourself.

For most personal and small-business documents, a visual signature in a PDF is enough. Use a digital signature service only if the document explicitly requires one or if you need proof that you signed it on a specific date.

Saving and sharing your signed PDF

After you add your signature, save the file with a new name that includes the date or "signed" — for example, "Lease_Signed_2024.pdf" instead of just "Lease.pdf." This keeps your original unsigned version safe in case you need to make changes or sign it differently.

When you email or upload the signed PDF, the signature stays embedded in the file. The person receiving it will see your signature exactly as you placed it. They can print it, save it, or sign it themselves if needed.

If multiple people need to sign the same document, send them the unsigned version first. Each person adds their signature and sends it back, or you can collect all the signatures yourself by opening each signed version and copying the signature images into a master document. This works for straightforward agreements but becomes tedious with more than two or three signers — that is when a service like DocuSign saves time.

Troubleshooting common signature problems

If your signature looks blurry or pixelated after you save, you drew it too small. Undo, draw it larger on the page, and save again. If the signature moved to a different spot after saving, your PDF reader may have reformatted the page — try saving as a different file format (like printing to PDF) to lock the signature in place.

If your PDF reader does not have a signature tool, make sure you are using the latest version. Check your app store or the software's website for updates. If updates do not add the feature, switch to Adobe Acrobat Reader or your device's built-in reader, both of which support signatures.

If you cannot find where to save the signed PDF, look for "File" > "Save" or "Export." Some readers save automatically to your Downloads folder or cloud storage. Check your device's file manager or cloud app to locate the signed version.

Frequently Asked Questions

Can someone forge my signature if I put it in a PDF?

Yes — a signature image in a PDF is just a picture, so anyone with the file can copy it and paste it into another document. For documents where forgery is a real risk, use a digital signature service that encrypts your identity into the signature. For everyday documents between people you trust, a visual signature is fine.

Does my signature have to be my actual handwriting?

No. You can type your name in a signature font, draw initials, or use any mark you want. What matters is that you and the other person agree it represents your consent. Typed signatures are common in business and work just as well as handwritten ones for non-legal documents.

What if I sign a PDF and then want to change something?

Open the original unsigned version, make your changes, and sign it again. If you only have the signed version, you can usually delete the signature image (right-click it and select delete or remove), make your edits, and sign again. Always keep the original unsigned file so you have this option.

Can I use the same signature image for every PDF I sign?

Yes. Save your signature as an image file the first time you create it, then upload that same image each time you sign a new PDF. This is faster than redrawing your signature every time and keeps your signature consistent across documents.

Is signing a PDF legally binding?

It depends on the document and your location. A visual signature in a PDF is usually treated the same as a printed signature for contracts, agreements, and most business documents. For legal documents like wills or powers of attorney, check your local laws — some require notarization or a digital signature instead. When in doubt, ask the other party or a lawyer whether your signed PDF is acceptable.