Home Phone comparison Samsung Galaxy S25 Ultra and Samsung Galaxy S21 Ultra - Which is better?

Samsung Galaxy S25 Ultra vs Samsung Galaxy S21 Ultra

94 out 100
Samsung Galaxy S25 Ultra
VS
67 out 100
Samsung Galaxy S21 Ultra
Samsung Galaxy S25 Ultra
Samsung Galaxy S21 Ultra

Compared 2 smartphones : Samsung Galaxy S25 Ultra Manufactured in February, 2025, with display 6.9 with chipsetQualcomm Snapdragon 8 Elite, vs Samsung Galaxy S21 Ultra, Manufactured in February, 2021with chipsetSamsung Exynos 2100. 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 S25 Ultra
  • Larger display: 6.9in
  • Lighter design: 218g vs 227g
  • Newer Bluetooth version: 5.4 vs 5.2
  • Supports DisplayPort
Reasons to choose Samsung Galaxy S21 Ultra
  • Higher pixel density: 515ppi

Versions

Available versions and configurations
Memory Options - 12/256 GB
- 12/512 GB
- 12/1024 GB
- 16/1024 GB		 - 12/128 GB
- 12/256 GB
- 12/512 GB
- 16/256 GB
- 16/512 GB

Review

Key Specs Samsung Galaxy S25 Ultra and Samsung Galaxy S21 Ultra
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
Adjust each parameter’s importance to find the best match for you.
Customize your score
Function
Importance (Weight)
Display:
Camera:
Performance:
Gaming:
Battery:
Connectivity:
Higher weight means greater impact on NanoReview score.

Tests & specs

Specs & test comparison
Smartphones:
Galaxy S25 Ultra
vs
Galaxy S21 Ultra

Display

Display quality comparison
Type Dynamic AMOLED Dynamic AMOLED
Size 6.9 in 6.8 in
Resolution 1440x3120 pixels 1440x3200 pixels
Aspect ratio 19.5:9 20:9
Pixel density 498 ppi 515 ppi
Refresh rate 120 Hz 120 Hz
Adaptive refresh rate Yes (1-120 Hz) Yes (10-120 Hz)
Max brightness 2600 nits 1500 nits
HDR support Yes HDR10+ Yes HDR10+
Touch Sampling Rate 240 Hz n/a
Screen-to-body ratio 92.4 % 89.5 %
Features - DCI-P3
- Always-On Display
- DC dimming		 - DCI-P3
- Always-On Display
Display test
Peak brightness (auto)
Samsung Galaxy S25 Ultra
1403 nits
Samsung Galaxy S21 Ultra
1019 nits
sRGB gamut97.7 %n/a
PWM (Flicker)240 Hzn/a
Response time1 msn/a
Contrast∞ Infiniten/a
Sources: NotebookCheck [Samsung Galaxy S25 Ultra], [Samsung Galaxy S21 Ultra]

Design & Build

Design and ergonomics comparison
Height 162.8 mm (6.41 in) 165.1 mm (6.5 in)
Width 77.6 mm (3.06 in) 75.6 mm (2.98 in)
Thickness 8.2 mm (0.32 in) 8.9 mm (0.35 in)
Weight 218 g (7.69 oz) 227 g (8.01 oz)
Water resistance IP68 IP68
Cooling system Vapor chamber n/a
Back panel Glass Glass
Frame Metal Metal
Colors - Black
- Silver
- Gray
- Blue		 - Black
- Silver
- Gray
- Blue
Fingerprint sensor Yes In-Display Yes In-Display
Screen-to-body ratio
Samsung Galaxy S25 Ultra
92.4 %
Samsung Galaxy S21 Ultra
89.5 %

Performance

Testing Samsung Galaxy S25 Ultra and Samsung Galaxy S21 Ultra In benchmarks
Processor
Chipset Qualcomm Snapdragon 8 Elite Samsung Exynos 2100
Max Frequency 4470 MHz 2900 MHz
CPU Cores 8 (2 + 6) 8 (1 + 3 + 4)
Architecture - 6/3.53 (Oryon (Phoenix M))
- 2/4.32 (Oryon (Phoenix L))		 - 4/2.2 (Cortex-A55)
- 3/2.81 (Cortex-A78)
- 1/2.91 (Cortex-X1)
Process TSMC Samsung
Transistor Size 3 nm 5 nm
Neural Processor Hexagon Yes
Graphics Adreno 830 Mali-G78 MP14
GPU Cores 1536 896
GPU Frequency 1100 MHz 854 MHz
FLOPS 3379.2 GFLOPS 1530.4 GFLOPS
GeekBench v6
Geekbench 6 (Single-Core)
Samsung Galaxy S25 Ultra
3147
Samsung Galaxy S21 Ultra
1449
Geekbench 6 (Multi-Core)
Samsung Galaxy S25 Ultra
9750
Samsung Galaxy S21 Ultra
3892
Geekbench 6 (Single-Core)31471449
Geekbench 6 (Multi-Core)97503892
Geekbench Compute (GPU)25681n/a
Sources: Geekbench v6 [Samsung Galaxy S25 Ultra]
AnTuTu 10
AnTuTu 10
Samsung Galaxy S25 Ultra
2795139
Samsung Galaxy S21 Ultra
843008
CPU659871232358
GPU1294167256356
Memory471319163007
UX369782191217
NanoReview Score2795139843008
3DMark Wild Life
3DMark Wild Life
Samsung Galaxy S25 Ultra
n/a
Samsung Galaxy S21 Ultra
5221
Max Surface Temp.n/a40.8 °C
Stabilityn/a69 %
Graphics Testn/a31 fps
Graphics Scoren/a5221
Sources: 3DMark [Samsung Galaxy S21 Ultra]

Memory

RAM
RAM Size - 12 GB
- 16 GB		 - 12 GB
- 16 GB
Memory Type LPDDR5X LPDDR5
Memory Frequency 5333 MHz 2750 MHz
Channels 2 2
Storage
Storage Capacity- 256 GB
- 512 GB
- 1024 GB		- 128 GB
- 256 GB
- 512 GB
Storage TypeUFS 4.0UFS 3.1
Memory CardNoNo

Software

OS Android 15 Android 11 (Upgradeable to Android 14)
OS Size 30.4 GB 26.4 GB
UI Skin One UI 7.0 One UI 6

Battery

Volume 5000 mAh 5000 mAh
Max Charging Power 45 W 25 W
Battery Type Li-ion Li-ion
Removable No No
Wireless Charging Yes (25 W) Yes (15 W)
Reverse Charging Yes (Wireless) Yes (Wireless)
Fast Charging Yes (72% in 30 min) Yes (54% in 30 min)
Full Charge Time 0:59 h 1:11 h
Battery Life Test
Battery Life
Samsung Galaxy S25 Ultra
31:10
Samsung Galaxy S21 Ultra
22:05
Web Browsing11:10 h07:58 h
Video Playback19:32 h13:59 h
Games06:22 h05:14 h
Standby Mode160 h111 h

Main camera

Matrix 200 MP 108 MP
Photo resolution 16320x12240 pixels 12000x9000 pixels
Zoom Optical, 5x Optical, 10x
Flash LED Dual LED
Stabilization Optical Optical
8K Recording Yes (Up to 30 fps) Up to 24FPS
4K Recording Yes (Up to 120 fps) Yes (Up to 60 fps)
1080p Recording Yes (Up to 240 fps) Yes (Up to 60 fps)
Slow Motion 240 fps (1080p) 960 fps (720p)
Wide-angle lens 120 ° 120 °
Lenses count Standard: 200 MP
Telephoto: 50 MP
Telephoto: 12 MP
Ultra-wide: 50 MP		 Standard: 108 MP
Telephoto: 10 MP
Telephoto: 10 MP
Ultra-wide: 12 MP
Features - Bokeh effect
- Pro mode
- RAW support		 - Bokeh effect
- Pro mode
- RAW support
Main lens
Matrix200 MP108 MP
Aperturef/1.7f/1.8
Focal length23 mm26 mm
SensorSamsung ISOCELL S5KHP2Samsung S5KHM3
Sensor size1/1.31/1.33
Pixel size0.6 μm0.8 μm
AutofocusPhase autofocusLaser autofocus
StabilizationOpticalOptical
Telephoto
Matrix50 MP10 MP
Aperturef/3.4f/4.9
Focal length111 mm240 mm
SensorSony IMX854Samsung S5K3J1
Sensor size1/2.521/2.65
Pixel size0.7 μm1.22 μm
StabilizationOpticalOptical
Ultra-wide lens
Matrix50 MP12 MP
Aperturef/1.9f/2.2
Focal length13 mm13 mm
SensorSamsung ISOCELL S5KJN3Sony IMX563
Sensor size1/2.51/2.55
Pixel size0.7 μm1.4 μm
StabilizationDigitalDigital
Main camera DxOMark results
Photo quality
Samsung Galaxy S25 Ultra
144
Samsung Galaxy S21 Ultra
121
Video quality
Samsung Galaxy S25 Ultra
143
Samsung Galaxy S21 Ultra
100
Overall camera score
Samsung Galaxy S25 Ultra
146
Samsung Galaxy S21 Ultra
115
Bokeh7070
Preview8167
Zoom149106
Sources: DxOMark [Samsung Galaxy S25 Ultra], [Samsung Galaxy S21 Ultra]

Front camera

Matrix 12 MP 40 MP
Photo resolution 4000x3000 pixels 7864x5200 pixels
Aperture f/2.2 f/2.2
Focal length 26 mm 26 mm
Sensor Samsung S5K3LU Samsung S5KGH1
Sensor size 1/3.2 1/2.65
Pixel size 1.12 μm 0.7 μm
Autofocus Phase autofocus (Dual Pixel) Phase autofocus
Stabilization Digital Digital
Video resolution 2160p (4K) at 60 fps 2160p (4K) at 60 fps
TOF 3D sensor No No
Selfie camera DxOMark results
Photo quality
Samsung Galaxy S25 Ultra
n/a
Samsung Galaxy S21 Ultra
133
Video quality
Samsung Galaxy S25 Ultra
n/a
Samsung Galaxy S21 Ultra
140

Connectivity

Wi-Fi version Wi-Fi 7 (802.11 a/b/g/n/ac/ax/be) Wi-Fi 6E (802.11 a/b/g/n/ac/ax)
Wi-Fi features - Dual Band
- Wi-Fi MiMO
- Wi-Fi Direct
- Wi-Fi Hotspot
- Wi-Fi Display		 - Dual Band
- Wi-Fi MiMO
- Wi-Fi Direct
- Wi-Fi Hotspot
- Wi-Fi Display
Bluetooth version 5.4 5.2
Bluetooth features LE LE, A2DP
USB type USB Type-C USB Type-C
USB version 3.2 3.2
USB features - Charging
- USB Storage Mode
- OTG		 - Charging
- USB Storage Mode
- USB-Host mode
- OTG
DisplayPort Yes DP 1.2 n/a
GPS - GPS
- GLONASS
- Beidou
- Galileo
- QZSS		 - GPS
- GLONASS
- Beidou
- Galileo
NFC* Yes Yes
Infrared Port No No
Connectivity
SIM Count*12
SIM TypeNanoNano
SIM ModeDual SIM StandbyDual SIM Standby
eSIM Support *YesYes
Hybrid SlotNoNo
2G BandsGSM850, GSM900, DCS1800, PCS1900GSM 850, 900, 1800, 1900 MHz
3G BandsUMTS B1(2100),B2(1900),B4(AWS),B5(850),B8(900)WCDMA Band 1, 2, 4, 5, 8
LTE Bands*LTE (B1/B2/B3/B4/B5/B7/B8/B12/B13/B14/B18/B19/B20/B25/B26/B28/B29/B30/B66/B71)LTE (B1/B2/B3/B4/B5/B7/B8/B12/B13/B17/B18/B19/B20/B25/B26/B28/B32/B38/B39/B40/B41/B66)
LTE categoryn/a24
5G SupportYesYes

Sound

Speakers Stereo Stereo
3.5 mm Jack No No
FM Radio No No
Dolby Atmos Yes Yes
Speaker Test
Max Volume
Samsung Galaxy S25 Ultra
93 dB
Samsung Galaxy S21 Ultra
88 dB

Other

Class Flagship Flagship
Announced January, 2025 yr January, 2021 yr
Release Date February, 2025 yr February, 2021 yr
Launch Price ($) 1299 1200
Sensors - Hall Sensor
- Barometer
- Proximity Sensor
- Gyroscope
- Accelerometer
- Ambient Light Sensor
- Compass
- Fingerprint sensor		 - Hall Sensor
- Barometer
- Proximity Sensor
- Gyroscope
- Accelerometer
- Ambient Light Sensor
- Compass
- Fingerprint sensor
Charger Included No n/a

Note

Samsung Galaxy S25 Ultra:

Supports up to 2 eSIMs. The international model has 2 physical SIM slots, while the U.S. version has 1.","Uses Grade 5 titanium and Corning Gorilla Armor 2 glass on both sides.

* Attention! Config, frequencies, NFC, and other specs may vary by region.

Results

After analyzing the data, we consider Samsung Galaxy S25 Ultra the clear winner in this comparison.

Survey

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Total Votes: 1

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