How to Use Your Second Laptop as a Monitor (Step-by-Step Guide for Windows & Mac)

If you are wondering how to use a second laptop as a monitor, you are not alone. Many people want more screen space for work, school, programming, trading, or design but do not want to buy an external monitor.

The good news is that you can turn your second laptop into a monitor extension using built-in tools or free software. This guide explains exact step-by-step methods that actually work on Windows and macOS, even for beginners.

By the end of this guide, you will know:

• How to extend your display to another laptop

• How to connect laptop to laptop on the same network

• The best free software to use

• How to fix common connection problems

What You Need Before You Start

Before setting up your second laptop as a monitor, confirm the following:

• Two laptops

• Both laptops powered on

• Both connected to the same Wi-Fi network

• Windows 10/11 or macOS

• Administrator access to install software

We will refer to:

• Main Laptop – the laptop you are working from

• Second Laptop – the laptop used as an extra screen

Method 1: Use Windows Built-In Wireless Display (No Software Required)

This method works on Windows 10 and Windows 11 and uses Miracast.

Step 1: Enable Wireless Display on the Second Laptop

1. Open Start

2. Go to Settings

3. Click System

4. Select Projecting to this PC

Set the following:

• Availability: Available everywhere

• Ask to project: First time only

• Require PIN: Optional

Leave this screen open.

Step 2: Connect from the Main Laptop

1. On the main laptop, press Windows + K

2. Select the second laptop from the list

3. Wait for the connection to complete

Step 3: Extend the Display

1. Press Windows + P

2. Choose Extend

You can now move your mouse between both laptops.

Step 4: Arrange Screens Properly

1. Right-click on desktop

2. Select Display settings

3. Drag screen 1 and 2 to match physical position

4. Click Apply

Limitations of This Method

• Can be unstable on slow Wi-Fi

• May not work on older laptops

• No advanced display controls

For best results, use Method 2.

Method 2: Use Spacedesk (Best and Most Reliable Option)

Spacedesk is the most recommended free solution for using a second laptop as a monitor.

Why Spacedesk Is Best

• Free

• Stable

• Works over Wi-Fi or USB

• Supports Windows-to-Windows

• Low system requirements

Step 1: Install Spacedesk on the Main Laptop

1. Open a browser

2. Search for Spacedesk official website

3. Download Spacedesk Driver for Windows (Primary PC)

4. Install and restart the laptop

Step 2: Set Up the Second Laptop

You have two options:

Option A: Web Viewer (No Installation)

1. Open a browser

2. Go to the Spacedesk Web Viewer page

Option B: Install Spacedesk Viewer

1. Download Spacedesk Viewer for Windows

2. Install normally

Step 3: Connect Both Laptops

1. Ensure both laptops are on the same Wi-Fi

2. Open Spacedesk Viewer on the second laptop

3. Click the name or IP of the main laptop

4. Wait a few seconds

The second screen will appear instantly.

Step 4: Set Display Mode to Extend

1. Right-click desktop on the main laptop

2. Select Display settings

3. Under Multiple displays, choose Extend these displays

4. Click Apply

Your second laptop now works like a real monitor.

Improve Performance (Important SEO Value)

To reduce lag:

• Lower screen resolution

• Use USB tethering instead of Wi-Fi

• Close background applications

Method 3: Use Sidecar on macOS (MacBooks Only)

Apple users can use Sidecar, which is built into macOS.

Requirements

• macOS Catalina or newer

• Same Apple ID on both devices

• Wi-Fi and Bluetooth enabled

Steps to Enable Sidecar

1. Open System Settings

2. Go to Displays

3. Click Add Display

4. Select the second Mac

5. Choose Extend Display

The second Mac becomes an external monitor automatically.

Common Problems and Fixes

Second laptop not showing

• Confirm same network

• Restart both devices

• Disable firewall temporarily

Lag or delay

• Lower resolution

• Switch to USB connection

• Close heavy apps

Mouse direction wrong

• Rearrange displays in settings

Best Uses for a Second Laptop as a Monitor

• Coding and programming

• Online classes and research

• Stock trading

• Video editing

• Office multitasking

• Graphic design

Frequently Asked Questions

Can I use a laptop as a second monitor without software?
Yes, on Windows 10/11 using wireless display, but results vary.

Is Spacedesk safe?
Yes, it is widely used and secure for local network connections.

Does this work over cable?
Yes, Spacedesk supports USB connections for better performance.

Conclusion

Using your second laptop as a monitor is one of the best free productivity upgrades you can make. With the right setup, you get more screen space without spending money on external monitors.

Follow the steps carefully, and you will get a working extended display setup.