How to Sign a PDF on Mac with Preview (Free)

Every Mac can sign PDFs for free with Preview, the app that opens PDFs by default. You do not need Adobe Acrobat or an account. Here is the complete process, including the three ways to capture your signature.

Sign a PDF in Preview, step by step

1. Open the PDF in Preview. Double-click it. If it opens in another app, Control-click the file and choose Open With → Preview.
2. Show the Markup toolbar. Click the Markup button (a pen tip in a circle) in the toolbar, or choose View → Show Markup Toolbar.
3. Click the Sign button (it looks like a signature) and choose Create Signature if you have not made one yet. More on the options below.
4. Insert your signature. Click the Sign button again and choose the signature. It appears in the middle of the page.
5. Position and resize it. Drag it onto the signature line; drag a corner handle to make it larger or smaller.
6. Save. Press Command-S. To keep the unsigned original, use File → Export as PDF and save a copy instead.

Three ways to create your signature in Preview

When you click Create Signature, Preview offers:

• Trackpad: click the text that tells you to begin, then sign with one finger on the trackpad. Press any key when you are done. Tip: sign slowly and larger than feels natural.
• Camera: sign your name in black ink on white paper and hold it up to the Mac’s camera, so the signature sits on the blue line. Preview captures it and removes the paper automatically. This usually gives the most realistic result.
• iPhone or iPad: choose your device and sign on its screen with your finger or Apple Pencil. The signature appears on the Mac as you draw.

Preview saves your signatures, so next time you just pick one from the Sign menu. Signatures are also available in other Apple apps that use Markup, such as Mail.

Sign a PDF attached to an email in Mail

1. Open the email and hover over the PDF attachment.
2. Click the small arrow that appears in its top-right corner and choose Markup.
3. Click the Sign button, choose your signature, place it and click Done.

The signed PDF is attached to a reply, ready to send.

Common problems

I don’t see the Sign button. Make sure the Markup toolbar is visible (View → Show Markup Toolbar) and that the file is a PDF. To sign a Word or Pages file, first choose File → Export as PDF (or Print → PDF → Save as PDF).

The signature is too thick or blurry. Recreate it with the Camera option using a felt-tip pen on clean paper, or import a high-resolution transparent signature PNG.

The document is locked. Some PDFs are protected against changes. Ask the sender for an unlocked version, or print it to a new PDF if you are allowed to.

Signing on the go

If you often receive documents on your phone, the Signature Maker app for iPhone and Android stores your signature and places it on PDFs and photos in a few taps, so you do not have to wait until you are back at your Mac. See how to sign a PDF on iPhone.

Frequently asked questions

How do I sign a PDF on a Mac for free?

Open it in Preview, click the Markup button, click the Sign button, create or choose your signature, place it and press Command-S. Preview is included with every Mac.

Can I type my signature in Preview?

No, Preview only captures a drawn or photographed signature. For a typed signature in a handwriting font, use the free signature generator, download the PNG and add it to the PDF.

How do I delete a signature in Preview?

Click the Sign button, hover over the signature in the menu and click the X that appears next to it. To remove a signature from a document, click it on the page and press Delete before saving.

Is a signature added with Preview legally valid?

For most everyday documents, yes: it is an electronic signature, recognised under the US ESIGN Act and the EU eIDAS Regulation. It is not a certificate-based digital signature; if the recipient requires one, see how to create a digital signature.