Xiaomi Redmi K40 Pro+ vs Samsung Galaxy S21 FE 5G: A Deep Dive Comparison

Both the Xiaomi Redmi K40 Pro+ and the Samsung Galaxy S21 FE 5G represent compelling options in the flagship-killer space, but cater to slightly different priorities. The K40 Pro+ aimed for raw performance at a disruptive price, while the S21 FE sought to deliver a refined Samsung experience with key flagship features. This comparison dissects their strengths and weaknesses to determine which device reigns supreme.
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🏆 Quick Verdict

For most users, the Samsung Galaxy S21 FE 5G emerges as the more balanced choice. While the Redmi K40 Pro+ boasts comparable processing power, the S21 FE’s superior display brightness, wireless charging, and more polished software experience justify its slightly higher price point.

PHONES
Phone Names Xiaomi Redmi K40 Pro+ Samsung Galaxy S21 FE 5G
Network
2G bandsGSM 850 / 900 / 1800 / 1900GSM 850 / 900 / 1800 / 1900
3G bandsHSDPA 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, 421, 2, 3, 4, 5, 7, 8, 12, 17, 20, 26, 28, 32, 38, 40, 41, 66 - International
5G bands1, 3, 28, 41, 77, 78 SA/NSA/Sub61, 3, 5, 8, 20, 28, 38, 40, 41, 66, 78 SA/NSA/Sub6 - International
SpeedHSPA, LTE, 5GHSPA 42.2/5.76 Mbps, LTE (5CA) Cat19 1600/200 Mbps, 5G
TechnologyGSM / CDMA / HSPA / CDMA2000 / LTE / 5GGSM / CDMA / HSPA / EVDO / LTE / 5G
 -41, 66, 71, 260, 261 SA/NSA/Sub6/mmWave - USA
Launch
Announced2021, February 252022, January 04
StatusAvailable. Released 2021, March 04Available. Released 2022, January 07
Body
Build-Glass front (Gorilla Glass Victus), plastic back, aluminum frame
Dimensions163.7 x 76.4 x 7.8 mm (6.44 x 3.01 x 0.31 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
Weight196 g (6.91 oz)177 g (6.24 oz)
 -IP68 dust/water resistant (up to 1.5m for 30 min)
Display
ProtectionCorning Gorilla Glass 5Corning Gorilla Glass Victus
Resolution1080 x 2400 pixels, 20:9 ratio (~395 ppi density)1080 x 2340 pixels, 19.5:9 ratio (~403 ppi density)
Size6.67 inches, 107.4 cm2 (~85.9% screen-to-body ratio)6.4 inches, 100.5 cm2 (~86.7% screen-to-body ratio)
TypeSuper AMOLED, 120Hz, HDR10+, 1300 nits (peak)Dynamic AMOLED 2X, 120Hz, HDR10+
 -Always-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, MIUI 12Android 12, up to 4 major Android upgrades, One UI 8
Memory
Card slotNoNo
Internal256GB 12GB RAM128GB 6GB RAM, 128GB 8GB RAM, 256GB 6GB RAM, 256GB 8GB RAM
Main Camera
FeaturesColor spectrum sensor, LED flash, HDR, panoramaLED flash, auto-HDR, panorama
Single-32 MP, f/2.2, 26mm (wide), 1/2.74", 0.8µm
Triple108 MP, f/1.8, 26mm (wide), 1/1.52", 0.7µm, PDAF 8 MP, f/2.2, 119˚ (ultrawide) 5 MP, f/2.4, 50mm (macro)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@30fps, 4K@30/60fps, 1080p@30/60/120/240/960fps, gyro-EIS, HDR10+4K@30/60fps, 1080p@30/60/120/240fps, HDR10+, gyro-EIS
Selfie camera
FeaturesHDRHDR
Single20 MP, f/2.5, (wide), 1/3.4", 0.8µm32 MP, f/2.2, 26mm (wide), 1/2.74", 0.8µm
Video1080p@30fps, 720p@120fps4K@30/60fps, 1080p@30/60fps, gyro-EIS
Sound
3.5mm jack -No
35mm jackNoNo
Loudspeaker Yes, with stereo speakersYes, with stereo speakers
 -32-bit/384kHz audio
Comms
Bluetooth5.2, A2DP, LE5.0, A2DP, LE
Infrared portYes-
NFCYesYes
PositioningGPS (L1+L5), GLONASS (G1), BDS (B1I+B1c+B2a), GALILEO (E1+E5a), QZSS (L1+L5), NavIC (L5)GPS, GLONASS, BDS, GALILEO
RadioNoUnspecified
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 (side-mounted), accelerometer, gyro, proximity, compass, barometerFingerprint (under display, optical), accelerometer, gyro, proximity, compass
 -Bixby natural language commands and dictation Samsung Pay (Visa, MasterCard certified) Samsung DeX (desktop experience support)
Battery
Charging33W wired, PD3.0, QC3, 100% in 52 min25W wired, PD3.0, 50% in 30 min 15W wireless Reverse wireless
TypeLi-Po 4520 mAhLi-Ion 4500 mAh
Misc
ColorsBlack, White, AuroraWhite, Graphite, Lavender, Olive
Models-SM-G990B, SM-G990B/DS, SM-G990U, SM-G990U1, SM-G990W, SM-G990E, SM-G9900, SM-G990B2, SM-G990U2, SM-G990W2, SM-G990U3
PriceAbout 470 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 92h
Camera- Photo / Video
Display- Contrast ratio: Infinite (nominal)
Loudspeaker- -26.9 LUFS (Good)
Performance- AnTuTu: 566529 (v8), 719696 (v9) GeekBench: 3049 (v5.1) GFXBench: 56fps (ES 3.1 onscreen)

Xiaomi Redmi K40 Pro+

  • Potentially lower price point
  • Snapdragon 888 offers strong performance
  • 33W fast charging is respectable

  • MIUI software can be polarizing
  • Charging speed is slower than S21 FE
  • Display brightness likely lower than S21 FE

Samsung Galaxy S21 FE 5G

  • Brighter and more color-accurate display
  • Wireless and reverse wireless charging
  • Refined Samsung One UI software

  • Exynos variant may exhibit more throttling
  • Charging speed is slower than some competitors
  • Potentially higher price

Display Comparison

The Samsung Galaxy S21 FE 5G boasts a significantly brighter display, reaching a measured 792 nits, compared to an unspecified brightness for the K40 Pro+. This makes the S21 FE more usable outdoors under direct sunlight. Both devices likely utilize AMOLED panels, but Samsung’s ‘Infinite’ contrast ratio suggests deeper blacks. While both will offer vibrant colors, the S21 FE’s superior brightness and potentially better color calibration provide a more visually pleasing experience for content consumption.

Camera Comparison

Both devices feature capable camera systems, but detailed sensor information is limited. The focus should be on image processing. Samsung typically leans towards vibrant, saturated colors, while Xiaomi often aims for a more natural look. The presence of OIS (Optical Image Stabilization) on both is crucial for stable video recording and sharper low-light photos. The usefulness of a 2MP macro camera on either device is questionable, as image quality is typically limited. Without specific sensor size details, it’s difficult to definitively declare a camera winner.

Performance

Both phones can be equipped with the Qualcomm Snapdragon 888 5G (5nm), meaning core performance – CPU and GPU – will be very similar in those configurations. However, the S21 FE also comes in an Exynos 2100 (5nm) variant. While the Exynos 2100 has slightly higher clock speeds on its Cortex-X1 core (2.9 GHz vs 2.84 GHz), real-world performance differences are often minimal. Thermal management will be crucial; the Snapdragon 888 is known to throttle under sustained load, and the S21 FE’s cooling solution will determine how effectively it mitigates this. Both devices utilize an Octa-core CPU configuration with the same Cortex-A78 and A55 cores, ensuring a smooth multitasking experience.

Battery Life

The Samsung Galaxy S21 FE 5G has an endurance rating of 92 hours, indicating solid battery life. The Redmi K40 Pro+’s battery capacity is not specified, but its 33W wired charging is slower than the S21 FE’s 25W wired charging, and the S21 FE adds the convenience of 15W wireless charging and reverse wireless charging. The S21 FE reaches 50% charge in 30 minutes, while the K40 Pro+ takes 52 minutes for a full charge. While faster charging is desirable, the S21 FE’s overall endurance and wireless charging capabilities give it an edge.

Buying Guide

Buy the Xiaomi Redmi K40 Pro+ if you prioritize maximum performance-per-dollar and are comfortable with Xiaomi’s MIUI software. It’s ideal for demanding gamers and power users who want a Snapdragon 888 without breaking the bank. Buy the Samsung Galaxy S21 FE 5G if you value a refined user experience, a brighter and more color-accurate display, and the convenience of wireless charging. It’s the better option for everyday users who appreciate Samsung’s ecosystem and software features.

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, potentially leading to thermal throttling during extended gaming. However, Samsung’s software optimizations and the phone’s cooling system mitigate this to some extent. Shorter gaming sessions are unlikely to be affected.
❓ Is the 33W charging on the Redmi K40 Pro+ fast enough for daily use?
While 33W charging is respectable, it's slower than the 25W wired and 15W wireless charging offered by the S21 FE. It will still provide a reasonable top-up during a short break, but won't be as quick as some competing devices.
❓ How does the software experience differ between MIUI on the K40 Pro+ and One UI on the S21 FE?
MIUI is known for its extensive customization options and feature set, but can also be perceived as bloated and occasionally intrusive with ads. One UI offers a cleaner, more polished experience with a focus on usability and Samsung’s ecosystem integration. Preference is subjective, but One UI is generally considered more refined.
❓ Does the S21 FE support high refresh rate gaming (90fps or higher) in popular titles like PUBG?
The S21 FE’s 120Hz display supports high refresh rate gaming in many titles, including PUBG. However, achieving consistently high frame rates depends on the game’s settings and the phone’s thermal conditions. Expect some frame rate drops during intense battles.