How to Use Your Tablet as a Second Monitor for Your Computer

What you need to know before you start

You can use a tablet as a second monitor by connecting it to your computer through software that mirrors or extends your display. The tablet sits beside or above your main monitor and shows windows, documents, or applications you drag over to it. This works with iPads, Android tablets, and Windows tablets, though the setup steps and available software differ for each.

The connection happens over your home network or USB cable—the tablet does not need to be plugged into power during use, though it will drain battery faster than normal. Most setups take 10 to 20 minutes to configure the first time. After that, the connection usually reconnects automatically when both devices are on the same network.

Key Takeaways

iPad users can use Apple's Sidecar feature (built into macOS and iPadOS) to extend the display wirelessly or over USB, with no additional software needed.
Windows and Android users need third-party software like Spacedesk, which runs free on Windows and Android devices and connects over your home network.
The tablet must be on the same Wi-Fi network as your computer, or connected by USB cable, depending on which software you use.
Extended display mode lets you drag windows to the tablet; mirroring mode shows the same screen on both devices and is less useful for productivity.
Older tablets or slower networks may show lag or stuttering, especially when moving windows or playing video on the extended display.

Using Sidecar on Mac and iPad

Sidecar is built into macOS 13.1 and later and iPadOS 13 and later, so you do not need to read anything. It works wirelessly if both devices are on the same Wi-Fi network and signed into the same Apple ID, or over USB if you prefer a more stable connection.

To set up Sidecar wirelessly, open System Settings on your Mac, go to Displays, and click "Add Display." Select your iPad from the list. On the iPad, you will see a prompt asking to allow the connection—tap Allow. The iPad screen will then show your Mac's extended desktop, and you can drag windows between the two screens.

If you want to use a USB cable instead, plug the iPad into your Mac with a Lightning or USB-C cable (depending on the iPad model). Open System Settings > Displays > Add Display and select your iPad. The USB connection is more stable and does not depend on Wi-Fi, which is useful if your network is slow or crowded.

Sidecar also lets you use the iPad as a drawing tablet with Apple Pencil if you have one. You can turn off the extended display and use the iPad only for input—this is called "Sidecar with Pen Only" mode.

Setting up Spacedesk on Windows and Android

Spacedesk is free software that turns an Android tablet or another Windows device into a second monitor for a Windows PC. read the Spacedesk Server software on your Windows computer from the official Spacedesk website, then read the Spacedesk app on your Android tablet from the Google Play Store.

After installing both, open Spacedesk Server on your Windows PC. You will see a window showing your computer's IP address and a list of connected devices (which will be empty at first). Open the Spacedesk app on your tablet. The app will scan your network and show available computers—tap your Windows PC to connect.

Once connected, your tablet screen will show an extended view of your Windows desktop. You can drag windows from your main monitor to the tablet by clicking and dragging them across the edge of the screen. The tablet acts as a true second monitor, not a mirror of the first one.

Both devices must be on the same Wi-Fi network. If the tablet does not find your computer, check that Windows Firewall is not blocking Spacedesk Server—you may need to allow it through the firewall manually in Windows Settings.

Connecting over USB instead of Wi-Fi

If your Wi-Fi is slow or unreliable, you can connect your tablet to your computer with a USB cable for a more stable connection. This works with Sidecar on Mac and iPad, and with some third-party apps on Android.

For Sidecar, straightforward plug the iPad into your Mac with a USB cable and follow the same steps as the wireless setup. The connection will automatically switch to USB and stay there as long as the cable is plugged in.

For Android tablets on Windows, Spacedesk does not support direct USB connection, but apps like Deskreen do. Deskreen is free and open-source; read it on your Windows PC and the Deskreen app on your Android tablet, then connect over USB by enabling USB debugging in your tablet's developer settings. This is more technical than Spacedesk but gives you a wired connection if you need it.

Choosing between extended and mirrored display

Extended display mode shows different content on each screen. Your main monitor displays one set of windows, and your tablet shows others. You can drag windows between them, which is why this mode is useful for productivity—you might keep email on the tablet and your main work on the monitor.

Mirrored mode shows the exact same screen on both devices. This is rarely useful for a second monitor setup because you are not gaining extra screen space. Mirrored mode is mainly used for presentations or when you want to show your screen to someone else.

Most second-monitor software defaults to extended mode. If you accidentally enabled mirrored mode, you can switch back in your display settings—on Mac, go to System Settings > Displays and uncheck "Mirror Displays"; on Windows with Spacedesk, the app defaults to extended mode and does not offer mirroring.

Troubleshooting lag and connection problems

If your tablet screen feels slow or stutters when you move windows, the issue is usually your Wi-Fi network. Move your tablet and computer closer to your router, or switch to a 5 GHz Wi-Fi band if your router supports it and both devices can connect to it. A USB connection will always be faster and more stable than Wi-Fi.

If the tablet does not find your computer on the network, restart both devices and make sure they are on the same Wi-Fi network (not a guest network). Check that your Windows Firewall or Mac firewall is not blocking the software—you may need to allow it manually in your security settings.

If the connection drops frequently, try using a USB cable instead. If you are using Sidecar on Mac and iPad, a USB connection is more reliable than wireless and is worth trying if you have a long enough cable.

Older tablets with slower processors may show noticeable lag even on a good network. If your tablet is more than five years old, you might experience stuttering when dragging windows or scrolling. In this case, using the tablet for static content like reference documents or chat windows (rather than video or animation) will feel smoother.

What you can and cannot do with a tablet as a second monitor

A tablet second monitor works well for reference material, chat windows, email, spreadsheets, and documents you want to keep visible while working on your main screen. It is also useful for keeping a video call or presentation on the tablet while you work on something else on your main monitor.

Do not expect the tablet to handle video playback smoothly or to keep up with fast-moving graphics. Games, video editing, and animation will stutter on a network connection. If you need to display video on the tablet, use a direct HDMI or USB-C connection instead (though this requires a tablet with video input, which is rare).

The tablet will drain battery faster than normal when used as a second monitor, especially over Wi-Fi. Plug it into power if you plan to use it this way for more than a few hours. Some tablets will throttle performance if the battery gets too hot, so keep it in a well-ventilated spot.

Frequently Asked Questions

Can I use an older iPad or Android tablet as a second monitor?

Yes, but older devices may be slow. iPad 5th generation and later work with Sidecar. Android tablets from roughly 2015 onward can use Spacedesk, though performance depends on the processor and how much RAM the tablet has. Test it first—if the connection is laggy, the tablet may not be a good fit for your workflow.

Do I need to buy software or pay a subscription?

No. Sidecar is built into macOS and iPadOS at no cost. Spacedesk is free. Deskreen is free and open-source. You do not need to pay for any of these.

What if my tablet and computer are not on the same Wi-Fi network?

Most second-monitor software requires the same network. If you are on different networks, use a USB cable instead (Sidecar supports this). Spacedesk does not support USB on Android, so you would need to switch to Deskreen or another app that supports wired connection.

Can I use my phone as a second monitor instead of a tablet?

Yes, the same software works on phones. Spacedesk runs on any Android phone, and Sidecar works on any iPhone. The smaller screen is less useful for productivity, but it works the same way as a tablet.

Will using a tablet as a second monitor slow down my computer?

Not noticeably. The software uses a small amount of CPU and network bandwidth, but modern computers handle this easily. You may see a slight drain on battery life if your computer is a laptop, but the impact is minimal.

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.