How to Sign a PDF on Mac — 3 Easy Methods (2025)

Mac users have several solid options for signing PDFs, ranging from the built-in Preview app to browser-based tools. Each method has its own strengths and trade-offs, and the best choice depends on what you need.

This guide covers three methods in detail: Apple's Preview app, the browser-based SigPDF, and Adobe Acrobat. By the end, you will know exactly which one to use and when.

Method 1: Using the Preview App (Built Into macOS)

Preview is the default PDF viewer on every Mac, and it includes a signature feature that many users overlook. No downloads or installations are needed — it is already on your machine.

Step-by-Step Instructions

1. Open your PDF in Preview. Right-click the file, select "Open With," and choose Preview. In most cases, double-clicking the PDF will open it in Preview by default.

2. Open the Markup toolbar. Click the Markup button in the toolbar — it looks like a pen tip inside a circle. Alternatively, go to View > Show Markup Toolbar.

3. Click the Signature button. In the Markup toolbar, click the signature icon (it looks like a cursive signature). If you have not created a signature before, you will be prompted to create one.

4. Create your signature. You have three options:

   • Trackpad: Use your finger to draw your signature on the trackpad. Click "Done" when you are satisfied.
   • Camera: Sign your name on a white piece of paper and hold it up to your Mac's camera. Preview will detect and capture the signature.
   • iPhone or iPad: If you have an iPhone or iPad signed into the same iCloud account, you can draw your signature on that device's touchscreen.

5. Place your signature. Click on the document where you want the signature to appear. Drag the corners to resize it and drag the signature itself to reposition it.

6. Save the document. Go to File > Export as PDF to save a new copy with your signature, or just press Command+S to save over the original.

Pros of Preview

• Pre-installed on every Mac — no setup required
• Saves your signature for reuse across documents
• Works offline with no internet connection
• iCloud sync lets you use signatures across Apple devices
• Camera capture is genuinely clever for importing ink signatures

Cons of Preview

• Signature drawing on a trackpad feels awkward and imprecise
• Limited formatting options (no typed signatures, no date stamps)
• No annotation tools beyond basic markup
• Only available on macOS — does not help if you also use Windows or Linux
• The camera method can be finicky with lighting and paper alignment

Method 2: Using SigPDF (Browser-Based)

SigPDF is a browser-based PDF signing tool that works on any operating system, including macOS. It requires no installation, no account creation, and processes your document entirely in your browser.

Step-by-Step Instructions

1. Open sigpdf.com in Safari, Chrome, or any browser on your Mac.

2. Upload your PDF. Drag your file onto the page or click to browse. The document loads in the built-in viewer.

3. Create your signature. Choose from three options:

   • Draw: Use your mouse or trackpad to draw your signature
   • Type: Enter your name and select from signature-style fonts
   • Upload: Import a PNG or JPG image of your existing signature

4. Position your signature. Click where you want it placed on the document. Drag to adjust the position and resize as needed.

5. Download the signed PDF. Click download and your signed document is saved to your Mac.

Pros of SigPDF

• No installation or account required
• Works in any browser on any operating system
• Client-side processing — your PDF never leaves your Mac
• Multiple signature creation methods including typed signatures
• Clean, straightforward interface with no bloat
• Equally usable on Mac, Windows, Linux, and mobile

Cons of SigPDF

• Requires an internet connection to load the web app (though processing is local)
• Does not save your signature between sessions (privacy feature, but less convenient for repeat use)
• No multi-party signing workflows

Method 3: Using Adobe Acrobat

Adobe Acrobat — both the free Reader version and the paid Pro version — offers PDF signing capabilities on Mac. The free version covers basic signing, while Pro adds advanced features.

Step-by-Step Instructions

1. Open your PDF in Adobe Acrobat. If you do not have it installed, download it from Adobe's website. The free Acrobat Reader is sufficient for basic signing.

2. Access the Fill & Sign tool. Go to Tools > Fill & Sign, or click "Fill & Sign" in the right-hand panel.

3. Create your signature. Click the "Sign" button in the toolbar, then "Add Signature." You can:

   • Type your name (Adobe applies a script-style font)
   • Draw your signature with your mouse or trackpad
   • Upload an image of your signature

4. Place and adjust. Click on the document to place your signature. Resize by dragging the handles.

5. Save. Go to File > Save As to create a new signed copy.

Pros of Adobe Acrobat

• Industry-standard PDF tool with broad compatibility
• Free Reader version handles basic signing
• Saves signatures to your Adobe account for reuse
• Robust form-filling capabilities beyond just signatures
• Strong support for accessibility features

Cons of Adobe Acrobat

• Requires downloading and installing software (several hundred MB)
• The free version is limited; many features require a paid Pro subscription ($19.99/month or more)
• Requires an Adobe account for full functionality
• The interface is heavy and complex for a simple signing task
• Documents may be processed through Adobe's servers
• Frequent update prompts and upsell notifications

Comparison: Which Method Should You Choose?

| Feature | Preview | SigPDF | Adobe Acrobat | |---|---|---|---| | Cost | Free | Free | Free (Reader) / Paid (Pro) | | Installation needed | No (pre-installed) | No | Yes | | Account required | No | No | Yes (for full features) | | Works offline | Yes | Needs initial load | Yes | | Client-side processing | Yes | Yes | Partial | | Typed signatures | No | Yes | Yes | | Drawn signatures | Yes | Yes | Yes | | Image upload | No (camera only) | Yes | Yes | | Cross-platform | macOS only | Any browser | Mac & Windows | | Signature storage | iCloud Keychain | None (by design) | Adobe Cloud |

Use Preview when:

• You are on your Mac with no internet connection
• You want the quickest possible route with no setup
• You only use Apple devices and want iCloud signature sync

Use SigPDF when:

• You want maximum privacy with client-side processing and no account
• You need typed signatures or want to upload a signature image
• You work across Mac, Windows, and mobile devices
• You want a fast, simple tool without software installation

Use Adobe Acrobat when:

• You already have it installed and are comfortable with the interface
• You need advanced form-filling features beyond simple signatures
• You work in an organization that standardizes on Adobe tools

Tips for Better PDF Signatures on Mac

Regardless of which method you choose, these tips will help you create cleaner, more professional-looking signatures:

1. If using a trackpad to draw, go slowly and deliberately. Quick strokes tend to look jagged. Some people find it easier to sign with their index finger on the trackpad rather than trying to replicate the motion of holding a pen.

2. Consider using a typed signature for a consistently clean result. Tools like SigPDF offer script-style fonts that look natural and are always legible.

3. If uploading a signature image, sign on plain white paper with a dark pen, photograph it in good lighting, and use an image with a transparent or white background.

4. Always save a copy of both the unsigned and signed versions of important documents.

5. Check the final result by opening the saved PDF in a different viewer to make sure the signature rendered correctly and is positioned where you intended.

Sign Your Next PDF on Mac

Whether you go with Preview, SigPDF, or Adobe Acrobat, signing a PDF on a Mac in 2025 is a straightforward process that takes less than a minute. For most people, the choice comes down to convenience and privacy — and a browser-based, no-account tool like SigPDF strikes the best balance of both.

Ready to sign your PDF? Try SigPDF free →

Frequently Asked Questions

Does the Preview app on Mac support typed signatures?

No. As of macOS Sonoma and Sequoia, Preview only supports drawn signatures (via trackpad, camera, or a connected iPhone/iPad). If you want to type your name and have it rendered in a handwriting-style font, you will need a tool like SigPDF or Adobe Acrobat.

Are signatures created on a Mac legally valid?

Yes. Electronic signatures created using any of the three methods described in this guide are legally valid under the ESIGN Act (U.S.), eIDAS (EU), and similar legislation in most countries. The tool you use to create the signature does not affect its legal standing — what matters is the intent to sign and the association of the signature with the document.

Can I sign a PDF on Mac without installing any software?

Yes. Your Mac comes with Preview pre-installed, which can handle basic signature tasks. Alternatively, SigPDF works entirely in your web browser with no installation. Both options let you sign PDFs without adding any new software to your Mac.

How do I sign a PDF on Mac if my trackpad signature looks bad?

If you struggle with trackpad signatures, try these alternatives: use the camera method in Preview to capture an ink-on-paper signature, use SigPDF to type your name in a signature font, or connect a drawing tablet for more precise input. Many people find that typed signatures look more professional than hand-drawn ones anyway.