Connect Your Samsung Phone as a Second Display

You can use your Samsung phone as a second monitor by connecting it to your computer through wireless casting, a USB cable, or a dedicated app. The easiest method depends on what device you're connecting to—Windows PC, Mac, or Linux—and whether you want a wired or wireless connection. Most Samsung phones support multiple connection methods, so you can choose based on what works best for your setup.

The wireless methods are fastest to set up if both devices are on the same network. Wired connections are more stable for long work sessions and don't drain your phone battery as quickly. Before you start, make sure your Samsung phone is charged to at least 50 percent and that your computer has the necessary software installed.

Key Takeaways

  • Samsung DeX is the built-in feature that turns your phone into a second monitor when connected via USB cable or wireless connection to a compatible Samsung device.
  • For Windows PCs, you can use third-party apps like Spacedesk or scrcpy to mirror or extend your display without needing Samsung DeX.
  • Wireless casting through Miracast (Windows) or AirPlay alternatives works on most Samsung phones but requires both devices on the same Wi-Fi network.
  • A USB cable connection is the most stable option and works when ready without software installation on many setups.
  • Your phone will continue to charge while connected via USB, but battery drain increases significantly during wireless casting.

Using Samsung DeX for Wired Connection

Samsung DeX is Samsung's official feature that lets you use your phone as a second display. To connect via USB cable, plug your Samsung phone into your computer using a USB-C cable. Your phone will ask for permission to allow USB debugging—tap Allow on the notification that appears on your phone screen.

On your computer, open Samsung DeX if it installed automatically, or read it from Samsung's website. The app will detect your phone within a few seconds. Once connected, your phone screen will appear as a second monitor in your display settings. You can drag windows between your main monitor and your phone, or extend your desktop across both screens. The connection is when ready and stable, and your phone charges while plugged in.

If your computer doesn't recognize the phone, check that USB debugging is enabled in your phone's Developer Options (Settings > About Phone > tap Build Number seven times, then go back and open Developer Options). Make sure you're using a data-capable USB cable, not a charging-only cable.

Wireless Connection Through Samsung DeX

To connect wirelessly, make sure both your phone and computer are on the same Wi-Fi network. Open Samsung DeX on your computer and look for your phone's name in the list of available devices. Tap it to connect. Your phone will show a confirmation prompt—accept it, and the wireless connection will establish within 10 to 15 seconds.

Wireless DeX works well for casual use, but the connection can drop if you move too far from your router or if another device uses heavy bandwidth. If the connection cuts out, straightforward reconnect from the DeX app. Wireless casting drains your phone battery faster than a wired connection, so keep your phone plugged into power if you plan to use it this way for more than an hour.

Using Spacedesk on Windows

Spacedesk is a free app that works on Windows PCs and most Android phones, including Samsung models. read the Spacedesk server software on your Windows computer from the official Spacedesk website, then install the Spacedesk app on your Samsung phone from the Google Play Store. Both devices must be on the same Wi-Fi network.

Open the server on your computer first, then open the app on your phone. Your computer's IP address will appear in the app—tap it to connect. Your phone screen will show your computer's display within a few seconds. You can adjust the resolution and refresh rate in the server settings if the display looks blurry or lags. Spacedesk is reliable for extended use and works with older Samsung phones that don't support DeX.

Casting Through Miracast (Windows Only)

Windows PCs have a built-in casting feature called Miracast that works with Samsung phones that support wireless display. On your Windows computer, open Settings, go to System, then Display. Scroll down and click Connect to a wireless display. Your computer will search for nearby devices.

On your Samsung phone, open Settings, go to Display, and look for Wireless Display or Smart View (the name varies by model). Turn it on and select your computer from the list. Once connected, your phone screen will mirror to your computer. This method works without installing extra software, but the connection is less stable than USB or DeX, and casting stops if your phone goes to sleep.

Troubleshooting Connection Problems

If your phone doesn't appear in the device list, restart both your phone and computer, then try again. Make sure both devices are on the same Wi-Fi network and that your phone's Wi-Fi is turned on. If you're using a USB cable, try a different cable or USB port on your computer—some ports don't support data transfer.

If the display is laggy or keeps disconnecting, move your phone closer to your Wi-Fi router or switch to a wired USB connection. Close other apps running in the background on your phone to free up processing power. If you're using Spacedesk or another third-party app, check that you've downloaded the latest version from the official source, not a third-party app store.

For DeX specifically, if the app doesn't recognize your phone, go to your phone's Settings, open Apps, find Samsung DeX, and clear the app cache. Then restart both devices and try connecting again. If USB debugging is causing issues, disable it in Developer Options after you've finished using the connection.

Choosing Between Wired and Wireless

Use a USB cable connection if you need the most stable setup for work that requires precision, like photo editing or spreadsheet work. The cable connection has no lag, doesn't drop, and keeps your phone charged. The downside is that you're tethered to your computer and can't move your phone around.

Use wireless casting if you want flexibility and don't mind occasional minor lag. Wireless works best for reading documents, browsing, or watching video on your second screen. Keep your phone plugged into a power bank if you'll be connected for more than an hour, since wireless casting drains the battery quickly. If your Wi-Fi is unstable or your router is far away, stick with the USB cable method instead.

Frequently Asked Questions

Do I need to install anything on my computer to use my Samsung phone as a second monitor?

It depends on the method. Samsung DeX requires you to read the DeX app on your Windows or Mac computer. Miracast is built into Windows, so no installation is needed. Spacedesk requires downloading the server software. If you're using a Mac, your options are more limited—DeX and Spacedesk are your best choices.

Can I use my Samsung phone as a second monitor while it's charging?

Yes, especially with a USB cable connection. Your phone will charge while you use it as a display. Wireless casting also works while charging, but you'll need to keep your phone plugged into power because the battery drains faster during wireless use.

What happens to my phone notifications while it's being used as a second monitor?

Notifications will still appear on your phone screen. If you're using a wired connection, you can dismiss them without interrupting the connection. With wireless casting, notifications may cause brief lag. You can silence notifications in your phone's Settings before you connect if you want an uninterrupted display.

Does using my phone as a second monitor slow down my computer?

No, the performance impact is minimal. Your computer uses a small amount of processing power to send the display signal, but it won't noticeably slow down everyday tasks like browsing or word processing. Wireless connections use slightly more resources than wired ones, but the difference is usually not noticeable.

Can I use my Samsung phone as a second monitor with a Mac?

Yes, but your options are limited compared to Windows. Samsung DeX works with Mac computers, and Spacedesk also supports Mac. Miracast is not available on Mac. read DeX or Spacedesk on your Mac, then follow the same connection steps as you would on Windows.