How to Sign PDF Documents on Mac Using the Preview App

When you receive a digital contract, lease agreement, or permission slip, the traditional workflow of printing the document, signing it with a pen, scanning it back into the computer, and emailing it is incredibly tedious. If you own a Mac, this entire process is unnecessary. Apple has built a powerful signature tool directly into Preview, the default PDF and image viewing application on macOS.

How to Create a Digital Signature in Preview

Before you can sign a document, you must create and save your signature in the Preview app. You only need to do this once; your Mac will securely store the signature for future use.

1. Open any PDF document using the Preview app.
2. Click the Show Markup Toolbar button. It looks like a pencil tip inside a circle, located near the top right of the window.
3. In the markup toolbar that appears below the main menu, click the Sign button (it looks like a small cursive signature).
4. Click Create Signature.

Methods for Capturing Your Signature

Preview offers three distinct methods for capturing a high-quality signature:

• Trackpad: If you are using a MacBook or a Magic Trackpad, select this option. Click “Click Here to Begin” and use your finger (or a capacitive stylus) to draw your signature directly on the trackpad. Press any key on your keyboard when finished, and click Done.
• Camera: This is often the best method for the most natural-looking signature. Sign your name clearly on a blank piece of white paper using a black pen. Hold the paper up to your Mac’s webcam. The camera will automatically detect the signature, extract the ink, and remove the paper background. Click Done to save it.
• iPhone or iPad: If your devices are logged into the same iCloud account, selecting this option will instantly ping your iPhone or iPad. A blank canvas will appear on your mobile device’s screen, allowing you to sign with your finger (or an Apple Pencil on iPad) and instantly send the high-resolution vector signature back to your Mac.

How to Insert Your Signature into a PDF

Once your signature is saved in the system, signing any future document takes only seconds.

1. Open the PDF contract in Preview.
2. Click the Show Markup Toolbar button (the pencil icon).
3. Click the Sign button. A dropdown menu will display all your saved signatures.
4. Click the signature you wish to use. It will appear in the center of the PDF document.
5. Click and drag the signature to the appropriate signature line on the document.
6. Click and drag the blue handles on the corners of the signature box to resize it so it fits perfectly on the line.

Once you are satisfied with the placement, simply save the document (Command + S) or export it. The signature is embedded into the PDF as a vector graphic, meaning it will remain crisp and professional regardless of how closely the recipient zooms in.