Adding a signature to a PDF on Mac requires nothing beyond Preview, which ships with every Mac. The whole process โ creating your signature and placing it on the document โ takes about two minutes the first time. After that, signatures are saved and reusing them takes seconds.
Step One: Create Your Signature in Preview
Open the PDF in Preview. Click the Markup toolbar icon โ the pen-tip button that appears in the top-right of the window. In the toolbar that appears, click the signature button, which looks like a cursive signature. A panel opens showing any signatures you've already saved, plus options to create a new one.
To create a signature, choose one of three methods. Trackpad: click "Trackpad" and draw your signature using your finger on the trackpad โ press any key when done. Camera: click "Camera," sign your name on a white piece of paper, hold it up to the camera, and Preview captures the signature shape automatically. iPhone or iPad: if you have an Apple device nearby, click the option to sign on your iPhone or iPad screen and your signature appears in Preview instantly.
Step Two: Place the Signature
Once created, click the signature in the panel and it appears on the PDF page. Drag it to the signature line. Use the corner handles to resize it โ make it proportional to the space available on the document. The signature is placed as an annotation, which means you can reposition or delete it before saving.
When the placement looks right, go to File โ Export as PDF to save the signed version. Don't use regular Save if you want to keep the original unsigned file intact โ Export as PDF creates a new file.
Reusing a Saved Signature
Preview saves your signatures permanently. The next time you need to sign a PDF, open it in Preview, click the Markup toolbar, click the signature button, and your saved signatures appear as thumbnail options. Click one and it drops onto the page, ready to position. You never need to redraw it.
Preview supports multiple saved signatures, so if you have different signing styles โ a formal signature for contracts and a more casual one for internal documents โ you can keep both available and pick the right one each time.
When the Camera Method Produces the Best Result
The camera method tends to produce the cleanest-looking signature because it captures your actual handwriting rather than a trackpad approximation. Sign with a dark pen on bright white paper, hold the paper up squarely to the camera in good lighting, and Preview outlines the signature shape automatically. The result is a clean, isolated signature image with a transparent background that looks natural on any document.
Alternative: Browser-Based Signing
If Preview's options don't suit your needs โ for instance, if you want to upload an existing signature image file rather than creating one through Preview's interface โ a browser-based Sign PDF tool gives you that flexibility. Upload the PDF, upload your signature image, position it, and download. This also works when you're on a Mac without access to Preview for any reason, or when you need to sign from someone else's computer.