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Global Score
Basic Information
Android 11Android 10
6.50 x 2.98 x 0.35 inches6.57 x 3.07 x 0.33 inches
8.04 ounces7.17 ounces
Phantom black and SilverTitan gray
Aluminum and Glass (Corning Gorilla Glass Victus)--
Scratch-Resistant Glass--
$ 966.00$ 174.00
Display / Screen
6.8 inches6.5 inches
3200 x 1440 pixels 1560 x 720 pixels
516 pixels per inch264 pixels per inch
1500 cd/m2 brightness--
No touch screenNo touch screen
Qualcomm Snapdragon 888 chipsetMediaTek Helio P22 MT6762 chipset
Kryo 680, 64-bit, 5 nm (Octa-Core 2840 MHz) processorArm Cortex-A53, 64-bit, 12 nm (Octa-Core 2000 MHz) processor
Adreno 660 GPUIMG PowerVR GE8320 GPU
128 GB internal memory32 GB internal memory
No SD card slotmicroSDXC (up to 1,95 TB) external memory slot
108.00 MP + 40.00 MP13.00 MP + 13.00 MP
f/1.80 aperturef/1.80 aperture
24.00mm focal length--
0.75 inches (1/1.33") sensor0.33 inches (1/3") sensor
7680 x 4320 (24 fps) video resolution1920 x 1080 (Full HD) video resolution
1280 x 720 (960 fps) (HD) slow motion video--
Mobile HotspotMobile Hotspot
5G, 5G, LTE-A (4G), LTE (4G), HSPA+ (4G), HSDPA and HSUPALTE-A (4G), LTE (4G), HSPA+ (4G), HSDPA and HSUPA
Nano SIMNano SIM
Battery Life
5000mAh Li - Polymer Battery4000mAh Li - Ion Battery
Non-Removable BatteryNon-Removable Battery
Wireless Charging--
Other Features
Bluetooth 5.1 Bluetooth 5.0
Fingerprint ID ScannerFingerprint ID Scanner
Accelerometer, Barometer, Compass, Gyroscope, Light Sensor and Proximity SensorAccelerometer, Compass, Gyroscope, Light Sensor and Proximity Sensor
FM RadioFM Radio

Comparison review

The Samsung Galaxy S21 Ultra has a score of 11.67, which is a lot better than the LG K51's 8.91 overall score. Both of these devices use Android OS, but the Samsung Galaxy S21 Ultra has newer 11 version and LG K51 has Android 10 version. The Samsung Galaxy S21 Ultra construction is just a bit thicker and somewhat heavier than LG K51.

Samsung Galaxy S21 Ultra features a much sharper screen than LG K51, because it has a lot greater screen pixel density, a quite larger screen and a much better 1440 x 3200px resolution. The LG K51 counts with a much bigger memory capacity to install games and applications than Galaxy S21 Ultra, because although it has just 32 GB internal memory capacity, it also counts with a slot for SD memory cards that admits a maximum of 1,95 TB.

Galaxy S21 Ultra counts with a bit faster CPU than LG K51, and although they both have the same number of cores, the Galaxy S21 Ultra also has a larger amount of RAM. Samsung Galaxy S21 Ultra features just a bit better battery lifetime than LG K51, because it has a 25% larger battery capacity. The Galaxy S21 Ultra features a way better camera than LG K51, and although they both have a F1.8 aperture, the Galaxy S21 Ultra also has a way larger sensor providing a way better image quality, a much more megapixels back-facing camera and a much higher 7680x4320 video quality.

Although Samsung Galaxy S21 Ultra is a better device, it costs a lot more than LG K51, and it doesn't have such a good relation between it's price and quality as the LG K51. If you are trying to save some money, you can buy LG K51, giving up a few features and specs, but you'll get the most with your budget.