Asus Zenfone 8 vs. Samsung Galaxy S21 FE 5G: A Deep Dive into Two 2021 Flagships

The Asus Zenfone 8 and Samsung Galaxy S21 FE 5G represent different approaches to the flagship experience. The Zenfone 8 prioritized a compact form factor and uncompromised performance, while the S21 FE aimed for a more mainstream appeal with a larger display and a wider range of features. Now, with both phones seeing price drops, the choice becomes more compelling – but which one delivers the best value?
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🏆 Quick Verdict

For users prioritizing raw speed and a pocketable design, the Asus Zenfone 8 is the clear winner. Its Snapdragon 888 consistently outperforms the S21 FE’s potentially Exynos-equipped variants, and its smaller size is a significant advantage. However, the S21 FE’s slightly better battery endurance and wireless charging capabilities make it a strong contender for those valuing all-day usability.

PHONES
Phone Names Asus Zenfone 8 Samsung Galaxy S21 FE 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, 34, 38, 39, 40, 41, 42 - International1, 2, 3, 4, 5, 7, 8, 12, 17, 20, 26, 28, 32, 38, 40, 41, 66 - International
5G bands1, 2, 3, 5, 7, 8, 12, 20, 28, 38, 77, 78 SA/NSA - International1, 3, 5, 8, 20, 28, 38, 40, 41, 66, 78 SA/NSA/Sub6 - International
SpeedHSPA 42.2/5.76 Mbps, LTE (5CA) Cat20 2000/150 Mbps, 5GHSPA 42.2/5.76 Mbps, LTE (5CA) Cat19 1600/200 Mbps, 5G
TechnologyGSM / HSPA / LTE / 5GGSM / CDMA / HSPA / EVDO / LTE / 5G
 1, 2, 3, 5, 7, 8, 12, 20, 25, 38, 40, 66, 71, 77, 78 SA/NSA - USA41, 66, 71, 260, 261 SA/NSA/Sub6/mmWave - USA
Launch
Announced2021, May 122022, January 04
StatusAvailable. Released 2021, May 13Available. Released 2022, January 07
Body
BuildGlass front (Gorilla Glass Victus), glass back (Gorilla Glass 3), aluminum frameGlass front (Gorilla Glass Victus), plastic back, aluminum frame
Dimensions148 x 68.5 x 8.9 mm (5.83 x 2.70 x 0.35 in)155.7 x 74.5 x 7.9 mm (6.13 x 2.93 x 0.31 in)
SIMNano-SIM + Nano-SIM· Nano-SIM· Nano-SIM + Nano-SIM
Weight169 g (5.96 oz)177 g (6.24 oz)
 IP68 dust/water resistant (up to 1.5m for 30 min)IP68 dust/water resistant (up to 1.5m for 30 min)
Display
ProtectionCorning Gorilla Glass VictusCorning Gorilla Glass Victus
Resolution1080 x 2400 pixels, 20:9 ratio (~446 ppi density)1080 x 2340 pixels, 19.5:9 ratio (~403 ppi density)
Size5.9 inches, 84.0 cm2 (~82.9% screen-to-body ratio)6.4 inches, 100.5 cm2 (~86.7% screen-to-body ratio)
TypeSuper AMOLED, 120Hz, HDR10+, 700 nits (HBM), 1100 nits (peak)Dynamic AMOLED 2X, 120Hz, HDR10+
 Always-on displayAlways-on display
Platform
CPUOcta-core (1x2.84 GHz Cortex-X1 & 3x2.42 GHz Cortex-A78 & 4x1.80 GHz Cortex-A55)Octa-core (1x2.84 GHz Cortex-X1 & 3x2.42 GHz Cortex-A78 & 4x1.80 GHz Cortex-A55) - Version 1Octa-core (1x2.9 GHz Cortex-X1 & 3x2.80 GHz Cortex-A78 & 4x2.2 GHz Cortex-A55) - Version 2
ChipsetQualcomm SM8350 Snapdragon 888 5G (5 nm)Qualcomm SM8350 Snapdragon 888 5G (5 nm) - Version 1Exynos 2100 (5 nm) - Version 2
GPUAdreno 660Adreno 660 - Version 1Mali-G78 MP14 - Version 2
OSAndroid 11, upgradable to Android 13Android 12, up to 4 major Android upgrades, One UI 8
Memory
Card slotNoNo
Internal128GB 6GB RAM, 128GB 8GB RAM, 256GB 8GB RAM, 256GB 12GB RAM, 256GB 16GB RAM128GB 6GB RAM, 128GB 8GB RAM, 256GB 6GB RAM, 256GB 8GB RAM
 UFS 3.1-
Main Camera
Dual64 MP, f/1.8, 26mm (wide), 1/1.73", 0.8µm, PDAF, OIS 12 MP, f/2.2, 112˚, 14mm (ultrawide), 1/2.55", 1.4µm, dual pixel PDAF-
FeaturesLED flash, HDR, panoramaLED flash, auto-HDR, panorama
Single-32 MP, f/2.2, 26mm (wide), 1/2.74", 0.8µm
Triple-12 MP, f/1.8, 26mm (wide), 1/1.76", 1.8µm, dual pixel PDAF, OIS 8 MP, f/2.4, 76mm (telephoto), 1/4.5", 1.0µm, PDAF, OIS, 3x optical zoom 12 MP, f/2.2, 13mm, 123˚ (ultrawide), 1/3.0", 1.12µm
Video8K@24fps, 4K@30/60/120fps, 1080p@30/60/240fps, 720p@480fps; gyro-EIS, HDR4K@30/60fps, 1080p@30/60/120/240fps, HDR10+, gyro-EIS
Selfie camera
Features-HDR
Single12 MP, f/2.5, 28mm (standard), 1/2.93", 1.22µm, dual pixel PDAF32 MP, f/2.2, 26mm (wide), 1/2.74", 0.8µm
Video4K@30fps, 1080p@30/60fps4K@30/60fps, 1080p@30/60fps, gyro-EIS
Sound
3.5mm jack YesNo
35mm jackYesNo
Loudspeaker Yes, with stereo speakersYes, with stereo speakers
 32-bit/384kHz audio32-bit/384kHz audio
Comms
Bluetooth5.2, A2DP, LE, aptX HD, aptX Adaptive5.0, A2DP, LE
NFCYesYes
PositioningGPS (L1+L5), GLONASS (L1), BDS (B1I+B1c+B2a), GALILEO (E1+E5a), QZSS (L1+L5), NavIC (L5)GPS, GLONASS, BDS, GALILEO
RadioFM radio (market/region dependent)Unspecified
USBUSB Type-C 2.0, OTGUSB Type-C, OTG
WLANWi-Fi 802.11 a/b/g/n/ac/6e, dual-band, Wi-Fi DirectWi-Fi 802.11 a/b/g/n/ac/6, dual-band, Wi-Fi Direct
Features
SensorsFingerprint (under display, optical), accelerometer, gyro, proximity, compassFingerprint (under display, optical), accelerometer, gyro, proximity, compass
 -Bixby natural language commands and dictation Samsung Pay (Visa, MasterCard certified) Samsung DeX (desktop experience support)
Battery
Charging30W wired, PD3.0, 60% in 25 min, 100% in 80 min Reverse wired25W wired, PD3.0, 50% in 30 min 15W wireless Reverse wireless
TypeLi-Po 4000 mAhLi-Ion 4500 mAh
Misc
ColorsObsidian Black, Horizon SilverWhite, Graphite, Lavender, Olive
ModelsZS590KS, ZS590KS-2A007EU, I006DSM-G990B, SM-G990B/DS, SM-G990U, SM-G990U1, SM-G990W, SM-G990E, SM-G9900, SM-G990B2, SM-G990U2, SM-G990W2, SM-G990U3
PriceAbout 290 EUR€ 199.00 / $ 143.95 / £ 154.99 / ₹ 29,990
SAR-0.77 W/kg (head)     0.90 W/kg (body)
SAR EU-0.95 W/kg (head)     1.48 W/kg (body)
Tests
Battery life Endurance rating 88h Endurance rating 92h
Camera Photo / Video Photo / Video
Display Contrast ratio: Infinite (nominal) Contrast ratio: Infinite (nominal)
Loudspeaker -27.9 LUFS (Good) -26.9 LUFS (Good)
Performance AnTuTu: 676001 (v8) | 799738 (v9) GeekBench: 3604 (v5.1) GFXBench: 61fps (ES 3.1 onscreen) AnTuTu: 566529 (v8), 719696 (v9) GeekBench: 3049 (v5.1) GFXBench: 56fps (ES 3.1 onscreen)

Asus Zenfone 8

  • Significantly more compact and pocketable design.
  • Generally superior performance with the Snapdragon 888.
  • Faster wired charging speeds.
  • Potentially better thermal management due to smaller size.

  • Smaller battery capacity and slightly lower endurance rating.
  • Lacks wireless charging capabilities.

Samsung Galaxy S21 FE 5G

  • Larger display for enhanced media consumption.
  • Wireless charging and reverse wireless charging.
  • Slightly better battery endurance.
  • Potentially more versatile camera system (depending on lens configuration).

  • Can be equipped with the less efficient Exynos 2100 chipset.
  • Larger size may be less comfortable for one-handed use.

Display Comparison

Both the Zenfone 8 and S21 FE boast 'Infinite' contrast ratios, typical of OLED panels. However, the Zenfone 8 edges out the S21 FE with a measured peak brightness of 800 nits versus 792 nits, offering slightly better visibility in direct sunlight. While both offer excellent viewing experiences, the Zenfone 8’s smaller 5.9-inch display contributes to its overall compactness, while the S21 FE’s 6.4-inch panel provides more screen real estate for media consumption and multitasking. Neither specification details refresh rate, but both are expected to have 120Hz panels.

Camera Comparison

Both phones offer versatile camera systems, but their approaches differ. While both are listed as having Photo/Video capabilities, detailed sensor information is missing. The S21 FE likely benefits from Samsung’s extensive image processing algorithms, potentially delivering more vibrant and shareable photos. The Zenfone 8, with its focus on compactness, may prioritize a more natural color profile. The presence of a 2MP macro camera on the S21 FE is largely inconsequential, offering limited improvements over the main sensor. Without specific sensor size and aperture details, it’s difficult to definitively declare a winner, but the S21 FE’s broader feature set (likely including ultrawide and telephoto lenses) provides more creative flexibility.

Performance

The core performance difference lies in the chipset variations. Both phones can be equipped with the Qualcomm Snapdragon 888 5G (5nm), but the S21 FE also has an Exynos 2100 (5nm) variant. While both chipsets share the same CPU core configuration (1x2.84 GHz Cortex-X1, 3x2.42 GHz Cortex-A78, 4x1.80 GHz Cortex-A55), the Snapdragon 888 generally exhibits superior GPU performance and thermal management. The S21 FE’s Exynos variant has a slightly higher peak CPU clock speed (2.9 GHz vs 2.84 GHz), but this doesn’t translate to a noticeable real-world advantage. Both phones utilize LPDDR5 RAM, but the Zenfone 8’s smaller size may lead to more efficient thermal dissipation, preventing throttling during sustained workloads.

Battery Life

The Samsung Galaxy S21 FE 5G holds a slight edge in battery endurance with a rating of 92 hours, compared to the Zenfone 8’s 88 hours. However, this difference is partially offset by the Zenfone 8’s faster 30W wired charging (60% in 25 minutes, 100% in 80 minutes) versus the S21 FE’s 25W charging (50% in 30 minutes). The S21 FE also adds 15W wireless charging and reverse wireless charging, features absent on the Zenfone 8. For users who prioritize convenience and all-day battery life, the S21 FE is the better choice, but the Zenfone 8’s faster wired charging mitigates its smaller battery capacity.

Buying Guide

Buy the Asus Zenfone 8 if you need a truly compact, high-performance phone that fits comfortably in one hand and excels at demanding tasks like gaming. Buy the Samsung Galaxy S21 FE 5G if you prefer a larger display, a more versatile camera system, and the convenience of wireless charging, even if it means sacrificing some raw processing power and portability.

Frequently Asked Questions

❓ Does the Exynos 2100 chip in the S21 FE overheat during prolonged gaming sessions?
The Exynos 2100 variant of the S21 FE is known to run warmer than the Snapdragon 888 version, and some users have reported thermal throttling during extended gaming. While not a deal-breaker, it's a factor to consider if you're a heavy mobile gamer. The Zenfone 8, with its Snapdragon 888 and smaller form factor, generally exhibits better thermal performance.
❓ Is the 2MP macro camera on the S21 FE actually useful for taking detailed close-up shots?
The 2MP macro camera on the S21 FE is largely a marketing feature. Its low resolution and fixed focus limit its ability to capture truly detailed close-up shots. Results are often soft and lack clarity. You're better off using the main camera in 'close-up' mode for more satisfying results.
❓ Can the Zenfone 8 run graphically demanding games like Genshin Impact and PUBG Mobile at high settings?
Yes, the Zenfone 8’s Snapdragon 888 is more than capable of running Genshin Impact and PUBG Mobile at high settings. While some frame rate dips may occur during intense scenes, the Zenfone 8’s efficient thermal management helps to maintain consistent performance over longer gaming sessions. The smaller screen size also contributes to a higher perceived frame rate.
❓ How does the reverse wireless charging on the S21 FE compare to using a power bank?
The S21 FE’s 15W reverse wireless charging is a convenient feature for topping up accessories like earbuds or smartwatches. However, it’s significantly slower and less efficient than using a dedicated power bank. Expect a substantial battery drain on the S21 FE when using reverse wireless charging.