The Samsung Galaxy M21s is a 2020 Android 10, One UI 2.5 smartphone powered by the Exynos 9611 (10 nm) with 4GB | 6GB and 128GB | 64GB internal storage. It features a 6.4", Super AMOLED, 420 nits (peak), 1080.0x2340.0 display and is available in Blue, Black.

The Galaxy M21s is equipped with a Li-Po 6000 mAh, a 64 MP, 4K@30fps, 1080p@30fps, gyro-EIS main camera, a 32 MP, 1080p@30fps front camera. The device uses a · Nano-SIM · Nano-SIM + Nano-SIM configuration. It weighs 191 g.

A bootloop on the Samsung Galaxy M21s occurs when the device repeatedly restarts without fully loading Android. This is commonly caused by a failed software update, corrupted system files, or an incompatible app. Most bootloops can be resolved without losing data by clearing the cache partition first before attempting a factory reset.

Factory reset may be needed as a last resort — erases all data.