How to Use an iPad as a Second Monitor for Your Computer

An iPad can work as a second monitor, but only with the right software and hardware setup

You can use an iPad as a second display for a Mac, Windows PC, or iPad by running software that mirrors or extends your desktop. The most common options are Apple's Sidecar (Mac and iPad only), third-party apps like Luna Display or Duet, or free tools like Spacedesk. The setup takes 10 to 15 minutes, but what you can actually do with the iPad screen depends on which app you choose, what devices you own, and whether you need wireless or wired connection.

The main trade-off is between simplicity and cost. Sidecar is free if you already own both devices, but only works with recent Macs and iPads. Paid apps like Duet or Luna Display work across more device combinations but cost $20 to $30 one-time or as a subscription. Free options like Spacedesk work on Windows and iPad but require more setup and may feel slower over a network.

Key Takeaways

Sidecar is the easiest option for Mac users with an iPad, but requires a Mac from 2016 or later and an iPad from 2015 or later running compatible software versions.
Third-party apps like Duet and Luna Display work on Windows and Mac with iPad, but cost money and may require a USB cable for the fastest performance.
Spacedesk is free and works on Windows with iPad, but requires both devices on the same Wi-Fi network and may have noticeable lag.
Your iPad will drain battery faster when used as a monitor, so plug it in or expect 2 to 4 hours of use before it dies.
The iPad screen becomes an extension of your main display, not a mirror, so you can drag windows between them like a real second monitor.

Using Sidecar on Mac and iPad

Sidecar is Apple's built-in feature for using an iPad as a second display on a Mac. It is the simplest option if you own both devices and they are recent enough. Your Mac must be from 2016 or later, and your iPad must be from 2015 or later. Both devices need to be signed in to the same Apple ID and connected to the same Wi-Fi network (or the iPad can be connected via USB).

To set up Sidecar, open System Preferences on your Mac, go to Sidecar, and click the iPad you want to use from the dropdown menu. The iPad screen will light up and become a second display within seconds. You can then drag windows from your Mac to the iPad, or use the iPad as a dedicated space for one app while you work on the Mac. The connection is wireless by default, but you can plug the iPad in with a USB cable for a more stable connection if you experience lag.

One limitation: Sidecar works only between a Mac and iPad, not between a Windows PC and iPad, and not between two iPads. If you need to extend a Windows display, you will need a different app.

Setting Up Duet or Luna Display on Windows or Mac

Duet and Luna Display are paid apps that work on both Windows and Mac with an iPad. Duet costs $20 one-time on the iPad and $20 on the computer, or $10 per month as a subscription. Luna Display costs $30 one-time or $8 per month. Both apps work over Wi-Fi or USB, and both let you drag windows between your main monitor and the iPad just like Sidecar does.

To set up either app, read it on your iPad from the App Store, then read the companion software on your Windows PC or Mac from the app's website. Plug the iPad in with a USB cable (or connect via Wi-Fi if you prefer), and the iPad will appear as a second display within a few seconds. The USB connection is faster and more stable, especially if you are moving windows or dragging files between screens. Wi-Fi works but may feel sluggish if your network is crowded.

Both apps include extra features like touch input on the iPad screen (so you can tap buttons on your main desktop), pressure sensitivity for drawing apps, and keyboard shortcuts. These features work better on Duet than Luna Display, but both are solid choices if Sidecar is not an option for your devices.

Using Spacedesk on Windows with iPad

Spacedesk is a free app that turns an iPad into a second monitor for a Windows PC. read the server software on your Windows computer from spacedesk.net, then read the Spacedesk app on your iPad from the App Store. Both devices must be on the same Wi-Fi network. Open the server on your PC, note the IP address it displays, then open the app on your iPad and enter that address to connect.

Spacedesk works over Wi-Fi only, so the connection is slower than a USB cable. You may notice a delay of half a second or more when dragging windows or moving the mouse to the iPad screen, which makes it less suitable for fast work like video editing or gaming. It works fine for email, web browsing, chat, or any task where a slight delay does not matter. The app is free, so it is worth trying if you already have a Windows PC and iPad before you spend money on Duet or Luna Display.

Choosing Between Wired and Wireless Connection

All of these apps can connect via Wi-Fi, but Sidecar, Duet, and Luna Display also support USB. A USB cable connection is faster and more stable because the data travels directly between devices instead of through your router. Use a USB cable if you are doing work that requires smooth, responsive performance, like dragging windows frequently, using the iPad as a drawing tablet, or moving large files between screens.

Wi-Fi is convenient because you do not have to plug anything in, but it depends on your network speed and how many other devices are using it. If your Wi-Fi is slow or crowded, you will notice lag. If you are just reading email or browsing on the iPad screen, Wi-Fi is fine. Test both and see which feels better for your actual work.

Battery and Power Considerations

Using an iPad as a second monitor drains its battery much faster than normal use. Expect the battery to drop 15 to 20 percent per hour, which means 4 to 6 hours of use before the iPad dies. If you plan to use the iPad as a second monitor for a full workday, plug it in with a power adapter or USB-C cable connected to your computer.

Most modern iPads support fast charging, so a 20W or higher power adapter will charge the iPad while you work. If you are using a USB cable to connect to your computer, the computer may not provide enough power to charge the iPad while it is also being used as a display, so a separate power adapter is safer. Check your iPad's specifications to see what wattage it supports.

Troubleshooting Common Problems

If the iPad does not appear as a second display, first check that both devices are on the same Wi-Fi network and signed in to the same Apple ID (for Sidecar) or that the app is installed on both devices. Restart both the iPad and the computer, then try connecting again. If you are using a USB cable, try a different cable or a different USB port on your computer.

If the connection is slow or laggy, move the iPad closer to your Wi-Fi router or switch to a USB cable. Close other apps on the iPad that might be using network bandwidth, like email or cloud sync. On your computer, check that no other apps are downloading large files. If you are using Spacedesk on Windows, the lag is normal over Wi-Fi; try Duet or Luna Display if you need faster performance.

If the iPad screen goes black or disconnects frequently, update both devices to the latest software version. Older software versions sometimes have bugs that cause connection problems. Check the App Store on your iPad and the Settings app on your Mac or Windows PC for pending updates.

Frequently Asked Questions

Can I use an iPad as a second monitor for a laptop while traveling?

Yes, as long as both devices are on the same Wi-Fi network. Sidecar, Duet, Luna Display, and Spacedesk all work over Wi-Fi, so you can set up a second display in a hotel, coffee shop, or anywhere with internet. USB connection is not practical while traveling, so expect some lag on Wi-Fi, especially on slower networks.

Does using an iPad as a second monitor work with video calls or streaming?

Yes, but it depends on your internet speed. If you are using Wi-Fi, the video call or stream on the iPad screen may lag or buffer because the connection is shared between the display data and the video data. A USB cable connection is more stable for this. Alternatively, use the iPad for something that does not need real-time performance, like notes or reference material, while your main monitor handles the video call.

Can I use an old iPad that I am no longer using?

Yes, as long as it is compatible with the app you choose. Sidecar requires an iPad from 2015 or later. Duet and Luna Display work on older iPads, though performance may be slower. Spacedesk works on most iPads. Check the App Store listing for the app you want to confirm your iPad model is supported before you read.

What if I want to use the iPad as a monitor for my iPhone or Android phone?

Sidecar does not work between iPhones and iPads. Duet and Luna Display do not support iPhone as a source device. Spacedesk does not work with phones. If you want a second screen for a phone, you would need a different solution, like a portable monitor designed for phones, which is outside the scope of these apps.

Is there a noticeable delay when I use the iPad as a second monitor?

Over USB, the delay is minimal and usually not noticeable. Over Wi-Fi, you may see a delay of 100 to 500 milliseconds depending on your network speed and the app. Spacedesk tends to have more lag than Duet or Luna Display. For most work, the delay is acceptable. For fast, precise tasks like drawing or gaming, a USB connection is better.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.