Xiaomi Redmi K40S vs Redmi K40: A Detailed Comparison

The Xiaomi Redmi K40 series delivered impressive value with the Snapdragon 870 chipset. But with the K40S arriving as a refresh, the question arises: is the upgrade worth it? This comprehensive comparison dives deep into the differences to help you decide which phone is right for you.

Phones Images

🏆 Quick Verdict

The Redmi K40S offers a significant advantage with its 67W fast charging, slashing charging times considerably. Both phones share the same powerful Snapdragon 870 processor, but the K40S's faster charging and potentially improved camera (based on general Redmi S series upgrades) make it the slightly better overall choice, especially if charging speed is a priority.

PHONES
Phone Names	Xiaomi Redmi K40S	Xiaomi Redmi K40

Network
2G bands	GSM 850 / 900 / 1800 / 1900	GSM 850 / 900 / 1800 / 1900
3G bands	HSDPA 850 / 900 / 1700(AWS) / 1900 / 2100	HSDPA 850 / 900 / 1700(AWS) / 1900 / 2100
4G bands	1, 2, 3, 4, 5, 8, 18, 19, 26, 34, 38, 39, 40, 41, 42	1, 2, 3, 4, 5, 7, 8, 18, 19, 26, 28, 34, 38, 39, 40, 41, 42
5G bands	1, 3, 5, 8, 28, 38, 40, 41, 77, 78 SA/NSA	1, 3, 28, 41, 77, 78 SA/NSA/Sub6
Speed	HSPA, LTE, 5G	HSPA, LTE, 5G
Technology	GSM / CDMA / HSPA / CDMA2000 / LTE / 5G	GSM / CDMA / HSPA / CDMA2000 / LTE / 5G
	CDMA2000 1x	CDMA2000 1x

Launch
Announced	2022, March 17	2021, February 25
Status	Available. Released 2022, March 17	Available. Released 2021, March 04

Body
Build	Glass front (Gorilla Glass 5), plastic back	-
Dimensions	163.2 x 76 x 7.7 mm (6.43 x 2.99 x 0.30 in)	163.7 x 76.4 x 7.8 mm (6.44 x 3.01 x 0.31 in)
SIM	Nano-SIM + Nano-SIM	Nano-SIM + Nano-SIM
Weight	195 g (6.88 oz)	196 g (6.91 oz)
	Splash resistant	-

Display
Protection	Corning Gorilla Glass 5	Corning Gorilla Glass 5
Resolution	1080 x 2400 pixels, 20:9 ratio (~395 ppi density)	1080 x 2400 pixels, 20:9 ratio (~395 ppi density)
Size	6.67 inches, 107.4 cm2 (~86.6% screen-to-body ratio)	6.67 inches, 107.4 cm2 (~85.9% screen-to-body ratio)
Type	AMOLED, 120Hz, HDR10+, 1300 nits (peak)	Super AMOLED, 120Hz, HDR10+, 1300 nits (peak)

Platform
CPU	Octa-core (1x3.2 GHz Kryo 585 & 3x2.42 GHz Kryo 585 & 4x1.80 GHz Kryo 585)	Octa-core (1x3.2 GHz Kryo 585 & 3x2.42 GHz Kryo 585 & 4x1.80 GHz Kryo 585)
Chipset	Qualcomm SM8250-AC Snapdragon 870 5G (7 nm)	Qualcomm SM8250-AC Snapdragon 870 5G (7 nm)
GPU	Adreno 650	Adreno 650
OS	Android 12, MIUI 13	Android 11, MIUI 12

Memory
Card slot	No	No
Internal	128GB 6GB RAM, 128GB 8GB RAM, 256GB 8GB RAM, 256GB 12GB RAM	128GB 6GB RAM, 128GB 8GB RAM, 256GB 8GB RAM, 256GB 12GB RAM
	UFS 3.1	UFS 3.1

Main Camera
Features	Color spectrum sensor, Dual-LED dual-tone flash, HDR, panorama	Color spectrum sensor, LED flash, HDR, panorama
Single	20 MP, (wide)	20 MP, f/2.5, (wide), 1/3.4", 0.8µm
Triple	48 MP, f/1.8, (wide), 1/2.0", 0.8µm, PDAF, OIS 8 MP, 119˚ (ultrawide) 2 MP (macro)	48 MP, f/1.8, 26mm (wide), 1/2.0", 0.8µm, PDAF 8 MP, f/2.2, 119˚ (ultrawide) 5 MP, f/2.4, 50mm (macro)
Video	4K@30fps, 1080p@30/60/120fps, 720p@960fps; gyro-EIS	4K@30fps, 1080p@30/60/120/240/960fps, gyro-EIS

Selfie camera
Features	-	HDR
Single	20 MP, (wide)	20 MP, f/2.5, (wide), 1/3.4", 0.8µm
Video	1080p@30/120fps	1080p@30fps, 720p@120fps

Sound
3.5mm jack	No	No
35mm jack	No	No
Loudspeaker	Yes, with stereo speakers	Yes, with stereo speakers
	24-bit/192kHz audio	24-bit/192kHz audio

Comms
Bluetooth	5.2, A2DP, LE	5.1, A2DP, LE
Infrared port	-	Yes
NFC	Yes	Yes
Positioning	GPS (L1+L5), GLONASS (L1), BDS (B1I+B1c+B2a), GALILEO (E1+E5a), QZSS (L1+L5), NavIC (L5)	GPS (L1+L5), GLONASS (G1), BDS (B1I+B2a), GALILEO (E1+E5a), QZSS (L1+L5), NavIC
Radio	No	No
USB	USB Type-C 2.0, OTG	USB Type-C 2.0, OTG
WLAN	Wi-Fi 802.11 a/b/g/n/ac/6, dual-band, Wi-Fi Direct	Wi-Fi 802.11 a/b/g/n/ac/6, dual-band, Wi-Fi Direct

Features
Sensors	Fingerprint (side-mounted), accelerometer, gyro, proximity, compass	Fingerprint (side-mounted), accelerometer, gyro, proximity, compass

Battery
Charging	67W wired, PD3.0, QC3, 100% in 38 min	33W wired, PD3.0, QC3, 100% in 52 min
Type	Li-Po 4500 mAh	Li-Po 4520 mAh

Misc
Colors	Black, Gray, Blue, Green	Black, White, Aurora
Models	-	M2012K11AC
Price	About 260 EUR	About 280 EUR

Xiaomi Redmi K40S

Faster 67W Charging
Potentially Improved Camera
Same Powerful Snapdragon 870
Excellent AMOLED Display

Slightly Higher Price
Minor Design Differences (subjective)

Xiaomi Redmi K40

Lower Price
Excellent AMOLED Display
Same Powerful Snapdragon 870
Capable Camera System

Slower 33W Charging
Potentially Slightly Inferior Camera

Display Comparison

Both phones feature a 6.67-inch AMOLED display with a 120Hz refresh rate and a Full HD+ resolution. While the panels are likely very similar, minor variations in color calibration or brightness might exist, but these are unlikely to be significant differences for most users. The K40S may have a slightly improved display calibration, but it's not a guaranteed upgrade.

Camera Comparison

The Redmi K40 boasts a 108MP main camera, an 8MP ultrawide, and a 2MP macro lens. The K40S is expected to have a slightly improved main sensor and potentially better image processing, though official details are scarce. Expect slightly better low-light performance and more refined image quality from the K40S, but the K40's camera is already very capable.

Performance

Performance is virtually identical. Both devices are powered by the Snapdragon 870 chipset, ensuring smooth performance for gaming, multitasking, and everyday use. You won't notice a difference in speed or responsiveness between the two.

Battery Life

The Redmi K40 has a 4500mAh battery and 33W charging. The Redmi K40S has the same 4500mAh battery but boasts a significantly faster 67W charging, capable of charging the phone from 0% to 100% in approximately 38 minutes, compared to the K40's 52 minutes. This is a major advantage for the K40S.

Buying Guide

The Xiaomi Redmi K40S is ideal for users who prioritize fast charging and potentially a slightly improved camera experience. The Redmi K40 remains a fantastic option for those seeking a powerful phone at a more budget-friendly price, especially if charging speed isn't a major concern.