Samsung DeX was introduced in 2017. Many years later, it continues to be the best way to enjoy a desktop-like experience via a smartphone or tablet. All modern flagship Galaxy phones and tablets support Samsung DeX, and Samsung continually makes improvements to the feature from time to time.
However, there is room for further improvement as DeX has a not-so-small list of limitations. One major limitation is the lack of support for 4K resolution.
Samsung DeX can project its desktop interface to external displays in multiple ways. You can connect wirelessly to any TV or monitor via Miracast screen mirroring (most smart TVs have this) or use a USB-C to HDMI cable. You can also use DeX on a Windows PC by connecting your device to it with a USB cable.
When you connect to a display using a USB-C to HDMI cable, DeX allows you to change the screen resolution. But the maximum supported resolution is WQHD (2560×1440). You can even be limited to 1080p depending on the TV you own, as televisions are generally designed to run at either 1080p or 4K and don’t support WQHD and other intermediate resolutions.
If that’s something that bothers you, don’t worry, Samsung’s Good Lock app can help. Good Lock enables many hacks and experimental functionalities that aren’t officially supported on One UI. One of those lets you enable higher resolutions in DeX.
For those wishing to run DeX at 4K resolution on their monitor or TV, we have prepared the guide below. It applies to both direct HDMI connections between the phone/tablet and display and connections made via a DeX dock, such as the one Samsung used to sell a few years ago.
First, download and install Good Lock and MultiStar
If Good Lock is available in your country, you can install it directly from the Galaxy Store. Once installed, open Good Lock and install MultiStar from the app’s Life up tab. Then, skip to the next section of the guide to find out how you can use MultiStar to enable 4K resolution in DeX.
If Good Lock isn’t available in your country, follow the steps below to manually download and install Good Lock and MultiStar before moving into the next section.
Step 1. First, let’s download and install Good Lock. Click this link in your mobile browser to open the Good Lock APKMirror page. On that page, scroll down to the All Versions section and hit the download button next to the latest version of the app.
Step 2. Scroll down to the Download Good Lock section and tap the download icon (highlighted in the screenshot below) once again.
Step 3. Scroll down once again and hit the DOWNLOAD APK button and the APK file should start downloading in a few seconds.
Step 4. Once the APK file is downloaded, open the My Files app on your device. The downloaded Good Lock file will show in the list of recent files at the top of My Files – tap it and follow the on-screen instructions to install the app.
Note: If you are installing an app manually for the first time, you will get a pop-up notification saying “your phone currently isn’t allowed to install unknown apps from this source.” To fix that, simply tap the Settings button on the pop-up notification, then tap the toggle button next to Allow Permission.
Step 5. Now, it’s time to get MultiStar. Click this link to visit the MultiStar APKMirror page and then perform the same steps as you did earlier for Good Lock to download and install the latest version of MultiStar.
Enable and activate 4K resolution in DeX
Once you have Good Lock and MultiStar installed, follow the steps below to enable 4K resolution.
Step 1. Open Good Lock, switch to the Life up section of the app, and tap MultiStar to open it.
Step 2. In MultiStar, tap I ♡ Samsung DeX, which is the very first option.
Step 3. In the I ♡ Samsung DeX menu, enable the High resolutions for external display option.
Step 4. Connect your phone or tablet to the display using an HDMI cable to fire up DeX mode, then open the Settings app via the app drawer or the shortcut on the DeX desktop.
Step 5. Select Samsung DeX to view all DeX settings.
Step 6. Tap Display resolution.
Step 7. Select the resolution you wish to use from the list of resolutions.
