How to Sign a PDF on Mac

Updated December 2025 • 6 min read

Mac users have several options for signing PDFs, from built-in tools to online solutions. This guide covers the best methods to electronically sign PDF documents on your MacBook, iMac, or Mac Mini.

3 Ways to Sign PDFs on Mac

Method 1: Using Preview (Built-in)

macOS includes Preview, a free app that can sign PDFs:

  1. Open your PDF in Preview (right-click → Open With → Preview)
  2. Click the Markup toolbar button (pencil icon) or go to View → Show Markup Toolbar
  3. Click the Signature button
  4. Choose "Create Signature" if you don't have one saved
  5. Create your signature using trackpad, camera, or iPhone
  6. Click on the PDF where you want the signature
  7. Resize and position as needed
  8. Save the document (File → Save or ⌘S)

Pros: Free, no internet required, built into macOS

Cons: Basic features only, can't send for others to sign

Method 2: Using Signatly Online (Recommended)

For more features and the ability to send documents to others:

  1. Go to signatly.com/free-tools/sign-pdf/
  2. Upload your PDF document
  3. Create your signature (type, draw, or upload)
  4. Place signature on the document
  5. Download or send to others for signature

Pros: Works on any Mac, send to others, audit trail, free to use

Cons: Requires internet connection

Method 3: Using Quick Look

For quick signatures without opening an app:

  1. Select the PDF in Finder
  2. Press Space to open Quick Look
  3. Click the Markup button (pencil icon)
  4. Click Signature and add your signature
  5. Click Done to save

Pros: Super quick, no app to open

Cons: Limited editing options

Creating a Signature on Mac

When using Preview or Quick Look, you have three ways to create your signature:

Using Your Trackpad

Sign directly on your Mac's trackpad using your finger. This creates the most natural-looking signature.

Using Your iPhone

If you have an iPhone connected to the same iCloud account, you can sign on your phone screen and it appears on your Mac.

Using Your Camera

Sign your name on white paper and hold it up to your Mac's camera. Preview will trace your signature automatically.

Need to Send PDFs for Others to Sign?

Try Signatly for free - send documents, track signatures, and get notified when signed.

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Which Method is Best?

It depends on your needs: