Samsung Galaxy A21s

Device specs

Chipset: Exynos 850
Operating system out of the box: Android 10 - One UI 2
Current operating system: Android 5.0 - One UI 4

Matching accessories*

Quick access

The most popular guides for this device.

Display & Home Screen

Remove a Widget from the Home Screen

A Samsung home screen crowded with widgets makes it hard to find the icons you actually use, and resizing or dragging them around rarely fixes the clutter. Removing a widget only clears it from the screen, the app behind it stays installed and unaffected. This applies to any placement, whether the widget was added manually or came preloaded on the device.

Open Notifications & Focus

Turn Camera and Screen Flash Notifications On or Off

If your Samsung phone stays completely dark when a new message or call comes in, flash notification is probably switched off. On top of the regular notification LED, many models can also pulse the camera flash or flash the screen for incoming alerts. With the feature disabled, you only find out about new notifications once you actively check the display.

Open Calls & Messages

Change Incoming Call Display While Using Apps

If a call pop-up covers half your screen every time someone rings while you are gaming or watching a video, the default call display setting is likely set to full screen or a large pop-up. Samsung lets you shrink that overlay to a mini pop-up so it stops blocking whatever app you are using. This setting sits in the call settings and controls only how calls look while an app is open in the foreground.

Open Display & Home Screen

Set Default Home Screen Launcher

Installing a new launcher from the Play Store does not always make it the active home screen on a Samsung phone. The device keeps falling back to its built-in interface every time you tap the Home button. This happens because the system default app for Home is still locked to the original launcher, not the one you just installed.

Open Network & Connectivity

Allow Both SIM Cards to Use Mobile Data During Calls

On a dual-SIM Samsung phone, taking a call on one SIM can cut off mobile data on the other, so messages stall and apps stop syncing until you hang up. This happens because only one SIM handles data by default while the second SIM pauses during the call. A hidden network toggle controls whether both SIMs can keep using data at the same time.

Open Network & Connectivity

Turn On or Off Auto Download for Software Updates over Wi-Fi

If your Samsung phone keeps fetching system update files the moment it joins a Wi-Fi network, even though you never opened the update screen, Auto download over Wi-Fi is switched on. The setting only pulls the update package onto the device; nothing gets installed without your confirmation. On phones with tight storage, this can quietly fill up space before you notice anything.

Open Display & Home Screen

Add a New Home Screen Page

Running out of room for icons and widgets on your Samsung home screen? New pages usually appear automatically once an existing page fills up, but that does not always happen. If Samsung One UI stops creating pages on its own, you need to add one manually to keep organizing apps and widgets.

Open Network & Connectivity

Enable or Disable SIM Card Lock

If your Samsung phone asks for a PIN every time it restarts, or you want that PIN request back after someone removed it, the SIM card lock setting is controlling this behavior. Carriers often turn this on by default so nobody else can use the SIM if the phone gets lost or stolen. Turning it off skips the PIN prompt at every restart, but it also removes that protection for the SIM itself.

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Ask a new question about the Galaxy A21s

Samsung Galaxy A21s

Device specs

Matching accessories*

Top guides

Quick access

Remove a Widget from the Home Screen

Turn Camera and Screen Flash Notifications On or Off

Change Incoming Call Display While Using Apps

Set Default Home Screen Launcher

Allow Both SIM Cards to Use Mobile Data During Calls

Turn On or Off Auto Download for Software Updates over Wi-Fi

Add a New Home Screen Page

Enable or Disable SIM Card Lock

Forum help

Samsung Galaxy A21s

Device specs

Matching accessories*

Top guides

Quick access

Remove a Widget from the Home Screen

Turn Camera and Screen Flash Notifications On or Off

Change Incoming Call Display While Using Apps

Set Default Home Screen Launcher

Allow Both SIM Cards to Use Mobile Data During Calls

Turn On or Off Auto Download for Software Updates over Wi-Fi

Add a New Home Screen Page

Enable or Disable SIM Card Lock