Home Phone comparison Samsung Galaxy S21 and Xiaomi Redmi Note 15 5G - Which is better?

Samsung Galaxy S21 vs Xiaomi Redmi Note 15 5G

65 out 100
Samsung Galaxy S21
VS
63 out 100
Xiaomi Redmi Note 15 5G
Samsung Galaxy S21
Xiaomi Redmi Note 15 5G

Compared 2 smartphones : Samsung Galaxy S21 Manufactured in February, 2021, with display 6.2 with chipsetSamsung Exynos 2100, vs Xiaomi Redmi Note 15 5G, Manufactured in August, 2025with chipsetQualcomm Snapdragon 6 Gen 3. Below are specs, tests, pros and cons for each device

  1. Differences
  2. Review
  3. Specs
  4. Benchmarks
  5. Battery Life
  6. Cameras
  7. Comments (0)

Key Differences

Device key advantages
Reasons to choose Samsung Galaxy S21
  • Higher pixel density: 421ppi
  • Lighter design: 169g vs 178g
  • Supports newer USB: 3.2 vs 2
  • Supports Dolby Atmos
  • Built-in eSIM
Reasons to choose Xiaomi Redmi Note 15 5G
  • Larger display: 6.77in
  • Higher battery capacity: 5800mAh vs 4000mAh
  • Newer Bluetooth version: 5.1 vs 5
  • Infrared port
  • Includes charger

Versions

Available versions and configurations
Memory Options - 8/128 GB
- 8/256 GB		 - 6/128 GB
- 8/128 GB
- 8/256 GB
- 12/256 GB

Review

Key Specs Samsung Galaxy S21 and Xiaomi Redmi Note 15 5G
Display
Color accuracy, sharpness & brightness
Camera
Main & front camera tests
Performance
App & system performance
Games
3D gaming performance
Battery
Battery life, charging speed & type
Connectivity
Connectivity features
NanoReview Score
Overall score by NanoReview
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Function
Importance (Weight)
Display:
Camera:
Performance:
Gaming:
Battery:
Connectivity:
Higher weight means greater impact on NanoReview score.

Tests & specs

Specs & test comparison
Smartphones:
Samsung Galaxy S21
vs
Redmi Note 15 5G

Display

Display quality comparison
Type Dynamic AMOLED AMOLED
Size 6.2 in 6.77 in
Resolution 1080x2400 pixels 1080x2340 pixels
Aspect ratio 20:9 n/a
Pixel density 421 ppi 388 ppi
Refresh rate 120 Hz 120 Hz
Adaptive refresh rate Yes (48-120 Hz) Yes (60-120 Hz)
Max brightness 800 nits n/a
HDR support Yes HDR10+ No
Screen-to-body ratio 85.9 % 89.1 %
Features - DCI-P3
- Always-On Display		 DCI-P3
Display test
Peak brightness (auto)
Samsung Galaxy S21
854 nits
Xiaomi Redmi Note 15 5G
n/a
sRGB gamut99.5 %n/a
PWM (Flicker)240 Hzn/a
Response time5 msn/a
Contrast∞ Infiniten/a
Sources: NotebookCheck [Samsung Galaxy S21]

Design & Build

Design and ergonomics comparison
Height 151.7 mm (5.97 in) 165 mm (6.5 in)
Width 71.2 mm (2.8 in) 75.4 mm (2.97 in)
Thickness 7.9 mm (0.31 in) 7.4 mm (0.29 in)
Weight 169 g (5.96 oz) 178 g (6.28 oz)
Water resistance IP68 IP68
Back panel Plastic n/a
Frame Metal Plastic
Colors - White
- Gray
- Pink
- Purple		 - White
- Black
- Blue
Fingerprint sensor Yes In-Display Yes, In-Display
Screen-to-body ratio
Samsung Galaxy S21
85.9 %
Xiaomi Redmi Note 15 5G
89.1 %

Performance

Testing Samsung Galaxy S21 and Xiaomi Redmi Note 15 5G In benchmarks
Processor
Chipset Samsung Exynos 2100 Qualcomm Snapdragon 6 Gen 3
Max Frequency 2900 MHz 2400 MHz
CPU Cores 8 (1 + 3 + 4) 8 (4 + 4)
Architecture - 4/2.2 (Cortex-A55)
- 3/2.81 (Cortex-A78)
- 1/2.91 (Cortex-X1)		 - 4/1.8 (Cortex-A55)
- 4/2.4 (Cortex-A78)
Process Samsung Samsung
Transistor Size 5 nm 4 nm
Neural Processor Yes Hexagon
Graphics Mali-G78 MP14 Adreno 710
GPU Cores 896 256
GPU Frequency 854 MHz 1010 MHz
FLOPS 1530.4 GFLOPS 517.1 GFLOPS
GeekBench v6
Geekbench 6 (Single-Core)
Samsung Galaxy S21
1331
Xiaomi Redmi Note 15 5G
1015
Geekbench 6 (Multi-Core)
Samsung Galaxy S21
3593
Xiaomi Redmi Note 15 5G
2890
Geekbench 6 (Single-Core)13311015
Geekbench 6 (Multi-Core)35932890
AnTuTu 10
AnTuTu 10
Samsung Galaxy S21
903780
Xiaomi Redmi Note 15 5G
608985
CPU253391200717
GPU281676141388
Memory158352118625
UX210361148255
NanoReview Score903780608985
3DMark Wild Life
3DMark Wild Life
Samsung Galaxy S21
5715
Xiaomi Redmi Note 15 5G
n/a
Max Surface Temp.38.9 °Cn/a
Stability66 %n/a
Graphics Test34 fpsn/a
Graphics Score5715n/a
Sources: 3DMark [Samsung Galaxy S21]
PCMark 3.0
PCMark 3.0
Samsung Galaxy S21
13123
Xiaomi Redmi Note 15 5G
n/a
Writing score16101n/a
Web score11909n/a
Video editing7097n/a
Data manipulation10153n/a
NanoReview Score13123n/a

Memory

RAM
RAM Size 8 GB 6 GB
Memory Type LPDDR5 LPDDR4X
Memory Frequency 2750 MHz 2133 MHz
Channels 2 2
Storage
Storage Capacity- 128 GB
- 256 GB		128 GB
Storage TypeUFS 3.1UFS 2.2
Memory CardNoNo

Software

OS Android 11 (Upgradeable to Android 14) Android 15
OS Size 28.1 GB n/a
UI Skin One UI 6.0 HyperOS 2.0

Battery

Volume 4000 mAh 5800 mAh
Max Charging Power 25 W 45 W
Battery Type Li-ion Li-Po
Removable No No
Wireless Charging Yes (15 W) No
Reverse Charging Yes (Wireless) Yes
Fast Charging Yes (55% in 50 min) Yes
Full Charge Time 1:35 h n/a
Battery Life Test
Battery Life
Samsung Galaxy S21
17:54
Xiaomi Redmi Note 15 5G
n/a
Web Browsing06:01 hn/a
Video Playback11:06 hn/a
Games04:21 hn/a
Standby Mode95 hn/a

Main camera

Matrix 12 MP 50 MP
Photo resolution 4000x3000 pixels n/a
Zoom Optical, 1.1x Digital
Flash Dual LED LED
Stabilization Optical Digital
8K Recording Up to 24FPS No
4K Recording Yes (Up to 60 fps) No
1080p Recording Yes (Up to 60 fps) Yes (Up to 30 fps)
Slow Motion 960 fps (720p) n/a
Wide-angle lens 120 ° n/a
Lenses count Standard: 12 MP
Telephoto: 64 MP
Ultra-wide: 12 MP		 Standard: 50 MP
Depth: 2 MP
Features - Bokeh effect
- Pro mode
- RAW support		 - Bokeh effect
- Pro mode
Main lens
Matrix12 MP50 MP
Aperturef/1.8f/1.8
Focal length26 mmn/a
SensorSony IMX555n/a
Sensor size1/1.761/2
Pixel size1.8 μm0.64 μm
AutofocusPhase autofocus (Dual Pixel)Phase autofocus
StabilizationOpticalDigital
Telephoto
Matrix64 MPn/a
Aperturef/2.0n/a
Focal length28 mmn/a
SensorSamsung Bright S5KGW2n/a
Sensor size1/1.72n/a
Pixel size0.8 μmn/a
StabilizationOpticaln/a
Ultra-wide lens
Matrix12 MPn/a
Aperturef/2.2n/a
Focal length13 mmn/a
SensorSony IMX563n/a
Sensor size1/2.55n/a
Pixel size1.4 μmn/a
StabilizationDigitaln/a
Main camera DxOMark results
Photo quality
Samsung Galaxy S21
129
Xiaomi Redmi Note 15 5G
n/a
Video quality
Samsung Galaxy S21
137
Xiaomi Redmi Note 15 5G
n/a
Overall camera score
Samsung Galaxy S21
133
Xiaomi Redmi Note 15 5G
n/a
Bokeh70n/a
Preview72n/a
Zoom126n/a
Sources: DxOMark [Samsung Galaxy S21]

Front camera

Matrix 10 MP 8 MP
Photo resolution 3872x2592 pixels n/a
Aperture f/2.2 f/2.0
Focal length 26 mm n/a
Sensor Sony IMX374 n/a
Sensor size 1/3.24 n/a
Pixel size 1.22 μm n/a
Autofocus Phase autofocus (Dual Pixel) No
Stabilization Digital Digital
Video resolution 2160p (4K) at 60 fps 1080p (Full HD) at 60 fps
TOF 3D sensor No No

Connectivity

Wi-Fi version Wi-Fi 6 (802.11 a/b/g/n/ac/ax) Wi-Fi 5 (802.11 a/b/g/n/ac)
Wi-Fi features - Dual Band
- Wi-Fi MiMO
- Wi-Fi Direct
- Wi-Fi Hotspot
- Wi-Fi Display		 - Dual Band
- Wi-Fi Direct
- Wi-Fi Hotspot
- Wi-Fi Display
Bluetooth version 5 5.1
Bluetooth features LE, A2DP LE
USB type USB Type-C USB Type-C
USB version 3.2 2
USB features - Charging
- USB Storage Mode
- USB-Host mode
- OTG		 - Charging
- USB Storage Mode
- OTG
DisplayPort n/a No
GPS - GPS
- GLONASS
- Beidou
- Galileo		 - GPS
- GLONASS
- Beidou
- Galileo
- QZSS
NFC* Yes Yes
Infrared Port No Yes
Connectivity
SIM Count*22
SIM TypeNanoNano
SIM ModeDual SIM StandbyDual SIM Standby
eSIM Support *YesNo
Hybrid SlotNoNo
2G BandsGSM 850, 900, 1800, 1900 MHzn/a
3G BandsWCDMA Band 1, 2, 4, 5, 8n/a
LTE Bands*LTE (B1/B2/B3/B4/B5/B7/B8/B12/B13/B17/B18/B19/B20/B25/B26/B28/B32/B38/B39/B40/B41/B66)n/a
LTE category24n/a
5G SupportYesYes

Sound

Speakers Stereo n/a
3.5 mm Jack No Yes
FM Radio No Yes
Dolby Atmos Yes n/a
Speaker Test
Max Volume
Samsung Galaxy S21
87 dB
Xiaomi Redmi Note 15 5G
n/a

Other

Class Flagship Mid-range
Announced January, 2021 yr August, 2025 yr
Release Date February, 2021 yr August, 2025 yr
Launch Price ($) 800 n/a
Sensors - Hall Sensor
- Barometer
- Proximity Sensor
- Gyroscope
- Accelerometer
- Ambient Light Sensor
- Compass
- Fingerprint sensor		 - Proximity Sensor
- Gyroscope
- Accelerometer
- Ambient Light Sensor
- Compass
- Fingerprint sensor
Charger Included n/a Yes, 45 W
* Attention! Config, frequencies, NFC, and other specs may vary by region.

Results

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