When you receive a contract, a tax form, or a lease agreement as a PDF file, you do not need to print it out, sign it with a pen, and scan it back into your computer. Apple has built a highly advanced digital signature tool directly into the native Preview application in macOS. It allows you to create a secure, vector-based digital signature using your Mac’s trackpad or a built-in webcam, which you can apply to any document in seconds.
How to Create Your Digital Signature
Before you can sign a document, you must capture your signature and save it to the Preview app. You only need to do this once.
- Locate the PDF document you need to sign and double-click it. It will open in the Preview application by default.
- Look at the top toolbar and click the Show Markup Toolbar button (it looks like a small pencil tip inside a circle).
- In the new toolbar that appears directly underneath, click the Sign button (which looks like a small, cursive signature).
- Click Create Signature.
A window will pop up offering three different ways to capture your signature:
- Trackpad: Click the “Click Here to Begin” button, then use your finger or a stylus to literally draw your signature on your Mac’s trackpad as if it were a piece of paper. Press any key when finished.
- Camera: Write your signature clearly on a blank piece of white paper using black ink. Hold the paper up to your Mac’s webcam. Preview will automatically scan the ink, strip away the white background, and vectorize it.
- iPhone/iPad: If your iPhone is nearby and signed into the same Apple ID, you can choose this option to instantly beam a blank canvas to your phone’s screen, allowing you to use your finger to sign on the touchscreen.
Once you are satisfied with how the signature looks, click Done. It is now securely saved to your Mac.
How to Apply the Signature to a PDF
Now that your signature is stored in the system, applying it to a new document takes only a few clicks.
- Open the PDF in Preview.
- Click the Show Markup Toolbar button (the pencil tip icon).
- Click the Sign button.
- A drop-down menu will appear showing the signature you previously created. Click it once.
Your signature will instantly drop into the exact center of the PDF page. It behaves like an image overlay.
You can now use your mouse to click and drag the signature precisely onto the signature line. You can also click the blue handles in the corners of the signature box to resize it, ensuring it fits perfectly within the designated space. Because the signature is a vector graphic, it will not become pixelated or blurry no matter how large or small you make it.
Once you are finished, simply save the file (Command + S) and close it. The signature is now permanently embedded in the PDF.