Free Step-by-Step Guide

How to Sign a PDF
The Complete Guide

Three ways to add your signature to any PDF document — free, fast, and legally binding. No special software required.

No credit card required · Works on any device

Recommended

Method 1: Sign a PDF with GoodSign

The easiest way to sign a PDF online. Works on any device, no software to install, and every signed document is legally binding with a full audit trail.

1

Create a free account

Go to goodsign.io/register and sign up in seconds. No credit card required, no subscription to manage. You only pay when you send a document for someone else to sign.

2

Upload your PDF

Drag and drop your PDF into GoodSign or click to browse. PDF, Word (DOCX), and image files are all supported. Your file is encrypted the moment it touches our servers.

3

Add your signature

Choose how you want to sign: draw your signature with your mouse or finger, type your name and pick a signature font, or upload an image of your handwritten signature. Place it anywhere on the document and resize to fit.

4

Download your signed PDF

Your signed PDF is ready instantly. The document is flattened and sealed with a tamper-proof audit trail. Download it or send it to others for their signature.

Why GoodSign is the best option

No software to install. Works on any device including phones and tablets. Every signed document includes a legally binding audit trail with timestamps and IP addresses. You can send PDFs to multiple signers, set up templates, and use automatic reminders. Learn more about signing PDFs online.

Method 2: Sign a PDF on Mac (Preview)

If you have a Mac, the built-in Preview app can add a basic signature to a PDF. No additional software needed, but there are important limitations.

1

Open the PDF in Preview

Double-click any PDF file on your Mac. By default, it opens in Preview. If another app opens instead, right-click the file, select Open With, and choose Preview.

2

Open the Markup toolbar

Click the Markup button (the icon that looks like a pen tip inside a circle) in the toolbar, or go to Tools then Annotate then Signature.

3

Create or select your signature

Click the Signature button, then Create Signature. You can draw on your trackpad, hold up a signed piece of paper to your camera, or sign on your iPhone or iPad if you have one nearby.

4

Place and save

Click your signature to place it on the document. Drag to position it and resize as needed. Save the file with Command + S.

Limitations of Preview

  • No audit trail or proof of signing
  • Not suitable for business or legal documents that need verification
  • No way to send a PDF to someone else for their signature
  • No multi-party signing workflow
  • Mac only — does not work on Windows, Android, or Linux

Method 3: Sign a PDF on Windows (Adobe Reader)

Adobe Acrobat Reader is free software that can add a basic signature to PDFs on Windows and Mac. Here is how to do it.

1

Open the PDF in Adobe Acrobat Reader

If you do not have it installed, download Adobe Acrobat Reader (free) from adobe.com. Open your PDF file in the application.

2

Open Fill & Sign

Click the Fill & Sign tool from the right-hand panel, or go to Tools then Fill & Sign. This opens the signing toolbar.

3

Add your signature

Click the Sign button in the toolbar, then Add Signature. You can type your name, draw your signature, or upload an image. Click Apply when finished.

4

Place and save

Click on the document where you want to place your signature. Resize as needed, then save the file.

Limitations of Adobe Reader

  • No audit trail or legally defensible proof of signing
  • Sending documents for others to sign requires a paid Adobe Acrobat subscription
  • Advanced features (templates, reminders, bulk send) require expensive plans
  • No multi-party signing in the free version
  • Requires installing desktop software

Compare your options

See how each method stacks up for signing PDF documents.

Feature GoodSign Mac Preview Adobe Reader
Free to sign
Legally binding audit trail
Send to others for signature Paid only
Multiple signers Paid only
Works on any device Mac only
No software to install Built-in Mac
Mobile-friendly Limited
Templates & reminders Paid only
Tamper-proof PDF
API access Paid only

When you need more than a simple signature

Preview and Adobe Reader work for adding a basic signature to a PDF. But if you need any of the following, you need a proper e-signature solution like GoodSign.

  • Multiple Signers

    Send a PDF to two, five, or twenty people for signature. Set the signing order or let everyone sign in parallel.

  • Legally Defensible Audit Trails

    Every action is recorded with timestamps, IP addresses, and device information. Holds up in court.

  • Reusable Templates

    Save any document as a template for repeated use. Perfect for contracts, NDAs, onboarding forms, and recurring documents.

  • Automatic Reminders

    Stop chasing signatures. GoodSign sends automatic reminder emails to signers who have not yet completed their documents.

  • Form Fields & Data Collection

    Add text fields, date pickers, checkboxes, and dropdown menus alongside signature fields to collect information.

  • Legal Compliance

    GoodSign is compliant with ESIGN, UETA, and eIDAS. Documents are tamper-proofed with 256-bit encryption.

Frequently asked questions

Yes. Electronic signatures on PDF documents are legally binding and enforceable in most countries worldwide. In the United States, the ESIGN Act and UETA give electronic signatures the same legal standing as handwritten signatures. In Europe, the eIDAS regulation provides the same recognition. For maximum legal protection, use a solution like GoodSign that provides a tamper-proof audit trail with timestamps, IP addresses, and device details as evidence of the signing event.

Yes. With GoodSign, you can sign any PDF directly from your phone's browser, whether it is an iPhone, Android, or tablet. Simply open the signing link in your mobile browser, draw your signature with your finger, and submit. No app download is needed. Preview (Mac only) and Adobe Reader also have mobile apps, but they have limited functionality compared to their desktop versions.

Not with GoodSign. It works entirely in your web browser, so there is nothing to download or install. Mac users can also use the built-in Preview app. Windows users can use Adobe Acrobat Reader (free download). However, for business documents that need audit trails and multi-signer support, an online tool like GoodSign is the better choice.

Yes. Signing a PDF is free with all three methods described in this guide. GoodSign is free for the person signing the document — they never need an account or to pay anything. The person sending the document pays a small per-document fee starting at $1.50. Preview and Adobe Reader are both free for basic signing, but Adobe charges for advanced features like sending documents to others.

Yes, but only with a dedicated e-signature platform like GoodSign. Preview and the free version of Adobe Reader only let you sign documents yourself — they have no sending workflow. With GoodSign, you upload your PDF, place signature fields where you need them, enter the recipient's email, and they receive a secure link to sign. You get notified when they are done and both parties receive a completed copy.

With GoodSign, you can add as many signers as you need. Upload your PDF, use the drag-and-drop designer to place signature fields for each person, and send. You can set sequential signing (one after the other) or parallel signing (everyone signs at once). Each signer receives their own secure link and the document is automatically completed once everyone has signed.

A legally valid electronic signature needs three elements: intent to sign (the signer deliberately chose to sign), consent to do business electronically, and a record of the signing event. GoodSign provides all three automatically through its audit trail, which records the signer's intent, consent, timestamp, IP address, device details, and geolocation for every signature.

Ready to sign your PDF?

Upload your document and add your signature in under a minute. Free for signers, no subscription required.

Sign Your PDF Now

No credit card required · No subscription · Set up in 30 seconds

All rights reserved © GoodSign Limited 2026
2 Stuart St, Ponsonby, Auckland 1011, New Zealand..