Asus Zenfone 7 Pro vs. Samsung Galaxy S21 Ultra 5G: A Detailed Comparison

Released in 2020, the Asus Zenfone 7 Pro now presents a compelling value proposition against the still-capable Samsung Galaxy S21 Ultra 5G, particularly as prices have adjusted. This comparison dissects the core differences between these two Android flagships, focusing on performance, display quality, camera capabilities, and battery endurance to determine which device best suits your needs.
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🏆 Quick Verdict

For the average user prioritizing a stunning display and versatile camera system, the Samsung Galaxy S21 Ultra 5G is the superior choice. However, the Asus Zenfone 7 Pro offers a compelling blend of performance and value, especially for those seeking a more compact form factor and aren't willing to pay a premium for Samsung's ecosystem.

PHONES
Phone Names Asus Zenfone 7 Pro Samsung Galaxy S21 Ultra 5G
Network
2G bandsGSM 850 / 900 / 1800 / 1900GSM 850 / 900 / 1800 / 1900
3G bandsHSDPA 800 / 850 / 900 / 1700(AWS) / 1900 / 2100HSDPA 850 / 900 / 1700(AWS) / 1900 / 2100
4G bands1, 2, 3, 4, 5, 7, 8, 12, 17, 18, 19, 20, 26, 28, 29, 38, 39, 40, 411, 2, 3, 4, 5, 7, 8, 12, 13, 14, 18, 19, 20, 25, 26, 28, 30, 38, 39, 40, 41, 46, 48, 66, 71 - SM-G998U1
5G bands1, 2, 3, 5, 7, 8, 12, 20, 28, 38, 77, 78 SA/NSA2, 5, 25, 41, 66, 71, 260, 261 SA/NSA/Sub6/mmWave - SM-G998U1
SpeedHSPA 42.2/5.76 Mbps, LTE (5CA) Cat19 1800/150 Mbps, 5G 3.6 Gbps DLHSPA 42.2/5.76 Mbps, LTE (7CA) Cat20 2000/200 Mbps, 5G (5+ Gbps DL)
TechnologyGSM / HSPA / LTE / 5GGSM / CDMA / HSPA / EVDO / LTE / 5G
 -1, 3, 5, 7, 8, 20, 28, 38, 40, 41, 66, 77, 78 SA/NSA/Sub6 - SM-G998B
Launch
Announced2020, August 26. Released 2020, September 012021, January 14
StatusDiscontinuedAvailable. Released 2021, January 29
Body
BuildGlass front (Gorilla Glass 6), glass back (Gorilla Glass 3), aluminum frameGlass front (Gorilla Glass Victus), glass back (Gorilla Glass Victus), aluminum frame
Dimensions165.1 x 77.3 x 9.6 mm (6.5 x 3.04 x 0.38 in)165.1 x 75.6 x 8.9 mm (6.5 x 2.98 x 0.35 in)
SIMNano-SIM + Nano-SIM· Nano-SIM + eSIM· Nano-SIM + Nano-SIM + eSIM (max 2 at a time)
Weight230 g (8.11 oz)227 g (Sub6), 229 g (mmWave) (8.01 oz)
 -IP68 dust/water resistant (up to 1.5m for 30 min) Stylus support
Display
ProtectionCorning Gorilla Glass 6Corning Gorilla Glass Victus
Resolution1080 x 2400 pixels, 20:9 ratio (~395 ppi density)1440 x 3200 pixels, 20:9 ratio (~515 ppi density)
Size6.67 inches, 107.4 cm2 (~84.2% screen-to-body ratio)6.8 inches, 112.1 cm2 (~89.8% screen-to-body ratio)
TypeSuper AMOLED , 90Hz, HDR10+, 700 nits (HBM)Dynamic AMOLED 2X, 120Hz, HDR10+, 1500 nits (peak)
 -Always-on display
Platform
CPUOcta-core (1x3.10 GHz Cortex-A77 & 3x2.42 GHz Cortex-A77 & 4x1.80 GHz Cortex-A55)Octa-core (1x2.9 GHz Cortex-X1 & 3x2.80 GHz Cortex-A78 & 4x2.2 GHz Cortex-A55) - InternationalOcta-core (1x2.84 GHz Cortex-X1 & 3x2.42 GHz Cortex-A78 & 4x1.80 GHz Cortex-A55) - USA/China
ChipsetQualcomm SM8250 Snapdragon 865 5G+ (7 nm+)Exynos 2100 (5 nm) - InternationalQualcomm SM8350 Snapdragon 888 5G (5 nm) - USA/China
GPUAdreno 650Mali-G78 MP14 - InternationalAdreno 660 - USA/China
OSAndroid 10, upgradable to Android 12, ZenUIAndroid 11, up to 4 major Android upgrades, One UI 6.1
Memory
Card slotmicroSDXC (dedicated slot)No
Internal256GB 8GB RAM128GB 8GB RAM, 128GB 12GB RAM, 256GB 12GB RAM, 256GB 16GB RAM, 512GB 12GB RAM, 512GB 16GB RAM
 UFS 3.1UFS 3.1
Main Camera
FeaturesDual-LED flash, HDR, auto panorama (motorized rotation)Laser AF, LED flash, auto-HDR, panorama
Quad-108 MP, f/1.8, 24mm (wide), 1/1.33", 0.8µm, PDAF, OIS 10 MP, f/2.4, 72mm (telephoto), 1/3.24", 1.22µm, dual pixel PDAF, OIS, 3x optical zoom 10 MP, f/4.9, 240mm (periscope telephoto), 1/3.24", 1.22µm, dual pixel PDAF, OIS, 10x optical zoom 12 MP, f/2.2, 13mm (ultrawide), 1/2.55", 1.4µm, dual pixel PDAF, Super Steady video
Triple64 MP, f/1.8, 26mm (wide), 1/1.72", 0.8µm, PDAF, OIS 8 MP, f/2.4, 80mm (telephoto), PDAF, OIS, 3x optical zoom 12 MP, f/2.2, 113˚, 17mm (ultrawide), 1/2.55", 1.4µm, dual pixel PDAF-
Video8K@30fps, 4K@30/60/120fps, 1080p@30/60/240fps, 720p@480fps; gyro-EIS, HDR8K@24fps, 4K@30/60fps, 1080p@30/60/120/240fps, HDR10+, stereo sound rec., gyro-EIS
Selfie camera
FeaturesDual-LED flash, HDR, auto panorama (motorized rotation)HDR
Single-40 MP, f/2.2, 26mm (wide), 1/2.8", 0.7µm, PDAF
TripleMotorized flip-up main camera module-
Video8K@30fps, 4K@30/60/120fps, 1080p@30/60/240fps, 720p@480fps; gyro-EIS, HDR4K@30/60fps, 1080p@30fps
Sound
3.5mm jack NoNo
35mm jackNoNo
Loudspeaker Yes, with stereo speakersYes, with stereo speakers
 24-bit/192kHz audio32-bit/384kHz audio Tuned by AKG
Comms
Bluetooth5.0, A2DP, LE, aptX Adaptive5.2, A2DP, LE
NFCYesYes
PositioningGPS (L1+L5), GLONASS (L1), BDS (B1+B2a), GALILEO (E1+E5a), QZSS (L1+L5), NavIC (L5)GPS, GLONASS, BDS, GALILEO
RadioNoFM radio (Snapdragon model only; market/operator dependent)
USBUSB Type-CUSB Type-C 3.2, OTG
WLANWi-Fi 802.11 a/b/g/n/ac/6, dual-band, Wi-Fi DirectWi-Fi 802.11 a/b/g/n/ac/6e, dual-band, Wi-Fi Direct
Features
SensorsFingerprint (side-mounted), accelerometer, gyro, proximity, compassFingerprint (under display, ultrasonic), accelerometer, gyro, proximity, compass, barometer
 -Samsung DeX, Samsung Wireless DeX (desktop experience support) Bixby natural language commands and dictation Samsung Pay (Visa, MasterCard certified) Ultra Wideband (UWB) support
Battery
Charging30W wired, PD3.0, 60% in 34 min, 100% in 93 min Reverse wired25W wired, PD3.0 15W wireless (Qi) 4.5W reverse wireless
TypeLi-Po 5000 mAhLi-Ion 5000 mAh
Misc
ColorsAurora Black, Pastel WhitePhantom Black, Phantom Silver, Phantom Titanium, Phantom Navy, Phantom Brown, Navy
ModelsZS671KS, ASUS_I002DDSM-G998B, SM-G998B/DS, SM-G998U, SM-G998U1, SM-G998W, SM-G998N, SM-G9980
PriceAbout 670 EUR$ 240.01 / C$ 353.20 / £ 202.99 / € 264.99
SAR-0.77 W/kg (head)     1.02 W/kg (body)
SAR EU-0.71 W/kg (head)     1.58 W/kg (body)
Pricing
128GB 12GB RAM-$ 384.99
256GB 12GB RAM-$ 998.00
512GB 12GB RAM-$ 1,179.99
RENEWED-$ 459.00
Tests
Battery lifeEndurance rating 99h Endurance rating 114h
Camera Photo / Video Photo / Video
Display Contrast ratio: Infinite (nominal) Contrast ratio: Infinite (nominal)
Loudspeaker -26.6 LUFS (Good) -25.5 LUFS (Very good)
Performance AnTuTu: 602934 (v8) GeekBench: 3302 (v5.1) GFXBench: 46fps (ES 3.1 onscreen) AnTuTu: 657150 (v8) GeekBench: 3518 (v5.1) GFXBench: 33fps (ES 3.1 onscreen)

Asus Zenfone 7 Pro

  • More affordable price point
  • Compact and ergonomic design
  • Excellent performance for the price

  • Less vibrant and brighter display
  • Inferior camera system compared to S21 Ultra
  • Slower charging speeds

Samsung Galaxy S21 Ultra 5G

  • Stunningly bright and vibrant display
  • Versatile and high-quality camera system
  • Longer battery life and wireless charging

  • Higher price tag
  • Larger and heavier form factor
  • Potential for Exynos overheating (depending on region)

Display Comparison

The Samsung Galaxy S21 Ultra boasts a significantly brighter display, reaching a measured 1023 nits compared to the Zenfone 7 Pro’s 741 nits. This translates to superior visibility in direct sunlight. Both displays share an 'Infinite' (nominal) contrast ratio, typical of OLED panels, but the S21 Ultra’s larger size and higher resolution contribute to a more immersive viewing experience. While neither spec sheet details refresh rate, the S21 Ultra is known to support adaptive 120Hz, a feature absent on the Zenfone 7 Pro, resulting in smoother scrolling and animations. The S21 Ultra’s panel is also likely LTPO, allowing for more granular refresh rate control and improved power efficiency.

Camera Comparison

Both phones offer versatile camera systems, but the S21 Ultra excels in zoom capabilities. While both are listed as having Photo/Video capabilities, the S21 Ultra’s larger main sensor and advanced image processing algorithms deliver superior image quality, particularly in low-light conditions. The S21 Ultra’s 10x optical zoom lens provides significantly greater reach than any zoom lens on the Zenfone 7 Pro. The Zenfone 7 Pro’s camera system is still capable, but lacks the sheer versatility and refinement of the S21 Ultra’s setup. The presence of a 2MP macro camera on the Zenfone 7 Pro is largely inconsequential, offering limited practical benefit compared to the S21 Ultra’s more robust camera array.

Performance

The Galaxy S21 Ultra’s chipset varies by region, utilizing either the Exynos 2100 (5nm) or the Qualcomm Snapdragon 888 (5nm). The Zenfone 7 Pro is powered by the Qualcomm Snapdragon 865 5G+ (7nm+). The 5nm process node of the S21 Ultra’s chips offers improved power efficiency and transistor density compared to the Zenfone’s 7nm+ node. The S21 Ultra’s CPU, featuring a Cortex-X1 prime core, provides a performance edge over the Zenfone 7 Pro’s Cortex-A77 prime core. However, both devices feature 12GB of RAM in certain configurations, mitigating potential performance bottlenecks. The Zenfone 7 Pro’s thermal management, given its smaller chassis, may be more prone to throttling under sustained load, while the S21 Ultra’s larger size allows for more effective heat dissipation.

Battery Life

The Samsung Galaxy S21 Ultra’s 114-hour endurance rating surpasses the Zenfone 7 Pro’s 99-hour rating, indicating longer battery life in real-world usage. While the Zenfone 7 Pro supports 30W wired charging, achieving 60% charge in 34 minutes and 100% in 93 minutes, the S21 Ultra’s 25W charging is slightly slower. However, the S21 Ultra adds 15W wireless charging and 4.5W reverse wireless charging, features absent on the Zenfone 7 Pro. The S21 Ultra’s larger battery capacity, combined with the more efficient chipset, contributes to its superior endurance.

Buying Guide

Buy the Asus Zenfone 7 Pro if you need a powerful, compact flagship with excellent performance for the price, and appreciate a more understated design. Buy the Samsung Galaxy S21 Ultra 5G if you prefer a larger, brighter display, a more comprehensive camera system with advanced zoom capabilities, and integration with the Samsung ecosystem.

Frequently Asked Questions

❓ Does the Exynos 2100 chip in the S21 Ultra suffer from overheating issues?
Early reports indicated potential thermal throttling with the Exynos 2100 variant, particularly during prolonged gaming sessions. However, software updates from Samsung have largely mitigated these issues. The Snapdragon 888 variant generally exhibits better thermal performance, but the difference is less pronounced with current firmware.
❓ Is the 2MP macro camera on the Zenfone 7 Pro actually useful?
The 2MP macro camera on the Zenfone 7 Pro is largely a marketing feature. Its low resolution and lack of optical image stabilization result in images that are often soft and lack detail. It's best to rely on the main camera for close-up shots.
❓ Does the Samsung Galaxy S21 Ultra support 90fps or higher frame rates in demanding games like PUBG?
The S21 Ultra can achieve frame rates exceeding 60fps in PUBG Mobile, but consistently hitting 90fps depends on the graphics settings and the specific chipset (Snapdragon generally performs better). Enabling the highest graphics settings may result in frame rate drops.
❓ How does the Zenfone 7 Pro's flip camera impact usability?
The flip camera is a unique feature that eliminates the need for a notch or punch-hole display. While initially novel, some users find the motor mechanism slightly noisy or worry about its long-term durability. However, it allows for consistently high-quality selfies and eliminates the risk of accidental camera activation during video calls.