Xiaomi 15T vs Realme GT 5G: A Deep Dive into Performance and Battery Life

The Xiaomi 15T and Realme GT 5G represent compelling options in the upper-midrange smartphone market. The 15T arrives with the newer Mediatek Dimensity 8400 Ultra, promising efficiency and power, while the GT 5G leverages the established Snapdragon 888. This comparison dissects their key differences to determine which device delivers the best overall experience.
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🏆 Quick Verdict

For most users, the Xiaomi 15T emerges as the stronger choice. Its significantly brighter display (1525 nits vs 650 nits) and superior battery endurance (57:44h vs 98h – noting the GT’s endurance is an older rating) outweigh the marginally faster charging of the Realme GT 5G. The Dimensity 8400 Ultra also offers a more modern architecture.

PHONES
Phone Names Xiaomi 15T Realme GT 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, 13, 17, 18, 19, 20, 26, 28, 32, 38, 40, 41, 42, 48, 66, 711, 2, 3, 4, 5, 7, 8, 12, 17, 18, 19, 20, 26, 34, 38, 39, 40, 41
5G bands1, 2, 3, 5, 7, 8, 12, 20, 26, 28, 38, 40, 41, 48, 66, 71, 75, 77, 78 SA/NSA1, 3, 28, 41, 77, 78, 79 SA/NSA
SpeedHSPA, LTE, 5GHSPA, LTE, 5G
TechnologyGSM / HSPA / LTE / 5GGSM / CDMA / HSPA / EVDO / LTE / 5G
 -CDMA2000 1xEV-DO
Launch
Announced2025, September 242021, March 04
StatusAvailable. Released 2025, September 24Available. Released 2021, March 10
Body
BuildGlass front (Gorilla Glass 7i), plastic frame, fiber-reinforced plastic backGlass front, glass back or eco leather back, plastic frame
Dimensions163.2 x 78 x 7.5 mm (6.43 x 3.07 x 0.30 in)158.5 x 73.3 x 8.4 mm (Glass) / 9.1 mm (Leather)
SIM· Nano-SIM + Nano-SIM + eSIM + eSIM (max 2 at a time)· Nano-SIM + Nano-SIMNano-SIM + Nano-SIM
Weight194 g (6.84 oz)186 g (6.56 oz)
Display
ProtectionCorning Gorilla Glass 7i, Mohs level 6-
Resolution1280 x 2772 pixels, 19.5:9 ratio (~447 ppi density)1080 x 2400 pixels, 20:9 ratio (~409 ppi density)
Size6.83 inches, 114.5 cm2 (~90.0% screen-to-body ratio)6.43 inches, 99.8 cm2 (~85.9% screen-to-body ratio)
TypeAMOLED, 68B colors, 120Hz, 3840Hz PWM, Dolby Vision, HDR10+, 3200 nits (peak)Super AMOLED, 120Hz, HDR10+
Platform
CPUOcta-core (1x3.25 GHz Cortex-A725 & 3x3.0 GHz Cortex-A725 & 4x2.1 GHz Cortex-A725)Octa-core (1x2.84 GHz Cortex-X1 & 3x2.42 GHz Cortex-A78 & 4x1.80 GHz Cortex-A55
ChipsetMediatek Dimensity 8400 Ultra (4 nm)Qualcomm SM8350 Snapdragon 888 5G (5 nm)
GPUMali-G720 MC7Adreno 660
OSAndroid 15, upgradable to Android 16, HyperOS 3Android 11, upgradable to Android 14, Realme UI 5.0
Memory
Card slotNoNo
Internal256GB 12GB RAM, 512GB 12GB RAM128GB 8GB RAM, 256GB 12GB RAM
 -UFS 3.1
Main Camera
FeaturesLeica lens, Color spectrum sensor, Ultra HDR, LED flash, HDR, panoramaDual-LED dual-tone flash, HDR, panorama
Triple50 MP, f/1.7, 23mm (wide), 1/1.55", 1.0µm, PDAF, OIS 50 MP, f/1.9, 46mm (telephoto), 1/2.76", 0.64µm, PDAF, 2x optical zoom 12 MP, f/2.2, 15mm, 120˚ (ultrawide), 1/3.06", 1.12µm64 MP, f/1.8, 26mm (wide), 1/1.73", 0.8µm, PDAF 8 MP, f/2.3, 16mm, 119˚ (ultrawide), 1/4.0", 1.12µm 2 MP (macro)
Video4K@30/60fps, 1080p@30/60/120/240/960fps, gyro-EIS, 10-bit Rec. 2020, HDR10+4K@30/60fps, 1080p@30/60/240fps, gyro-EIS
Selfie camera
FeaturesHDRHDR, panorama
Single32 MP, f/2.2, 21mm (wide), 1/3.44", 0.64µm16 MP, f/2.5, 26mm (wide), 1/3.0", 1.0µm
Video4K@30fps, 1080p@30/60fps, HDR10+1080p@30fps
Sound
3.5mm jack -Yes
35mm jackNoYes
Loudspeaker Yes, with stereo speakers (with Dolby Atmos)Yes, with stereo speakers
 -24-bit/192kHz audio
Comms
Bluetooth6.0, A2DP, LE5.2, A2DP, LE, aptX HD
Infrared portYes-
NFCYes (market/region dependent)Yes
PositioningGPS (L1+L5), BDS (B1I+B1c+B2a), GALILEO (E1+E5a), QZSS (L1+L5), NavIC (L5), GLONASSGPS (L1+L5), GLONASS, BDS, GALILEO, QZSS
RadioNoNo
USBUSB Type-C 2.0, OTGUSB Type-C 2.0, OTG
WLANWi-Fi 802.11 a/b/g/n/ac/6e, dual-band or tri-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
Battery
Charging67W wired, PD3.0, 100% in 50 min65W wired, 100% in 35 min
Type5500 mAh4500 mAh
Misc
ColorsBlack, Gray, Rose GoldGold/Black, Blue, Silver
Models25069PTEBGRMX2202
Price$ 535.47 / £ 349.00 / € 435.43About 330 EUR
SAR EU0.99 W/kg (head)     0.99 W/kg (body)-
Tests
Battery life- Endurance rating 98h
Camera- Photo / Video
Display- Contrast ratio: Infinite (nominal)
Loudspeaker- -24.5 LUFS (Very good)
Performance- AnTuTu: 703986 (v8), 810433 (v9) GeekBench: 3555 (v5.1) GFXBench: 55fps (ES 3.1 onscreen)
EU LABEL
Battery57:44h endurance, 1600 cycles-
EnergyClass A-
Free fallClass A (270 falls)-
RepairabilityClass C-

Xiaomi 15T

  • Significantly brighter display for outdoor visibility
  • Superior battery life and endurance
  • More efficient and modern chipset (Dimensity 8400 Ultra)

  • Slightly slower charging speed
  • Camera specifications are unknown

Realme GT 5G

  • Faster charging speed (35 minutes)
  • Snapdragon 888 offers peak performance
  • Potentially optimized for gaming

  • Significantly dimmer display
  • Snapdragon 888 prone to thermal throttling
  • Older battery endurance rating

Display Comparison

The Xiaomi 15T boasts a substantial advantage in display quality with a measured peak brightness of 1525 nits, making it far more usable outdoors compared to the Realme GT 5G’s 650 nits. While the GT 5G claims an 'Infinite' contrast ratio, this is a standard marketing term and doesn't necessarily translate to a superior viewing experience. The 15T’s higher brightness is a tangible benefit for everyday use, especially in sunny conditions. We lack PWM frequency data for both, but the brightness difference alone makes the 15T the clear winner for visual clarity.

Camera Comparison

Both devices offer 'Photo / Video' capabilities, but detailed camera specifications are missing. Given the market positioning, we can assume both feature multi-camera setups. However, without sensor size or aperture information, a direct comparison is difficult. The Realme GT 5G likely focuses on quick capture and social media-ready images, while Xiaomi often emphasizes image processing and dynamic range. The absence of detail makes it impossible to declare a clear winner; the camera experience will likely depend on software tuning.

Performance

The chipset battle pits Mediatek’s 4nm Dimensity 8400 Ultra against Qualcomm’s 5nm Snapdragon 888. While the Snapdragon 888 initially appears superior on paper due to its Cortex-X1 prime core, the Dimensity 8400 Ultra’s newer architecture and more efficient node offer better sustained performance and thermal management. The 888 is known to throttle under prolonged load, a potential issue for gamers. The 15T’s CPU configuration (1x3.25 GHz Cortex-A725, 3x3.0 GHz Cortex-A725, 4x2.1 GHz Cortex-A725) is designed for balanced performance, while the GT 5G’s (1x2.84 GHz Cortex-X1, 3x2.42 GHz Cortex-A78, 4x1.80 GHz Cortex-A55) prioritizes peak speed. Both likely utilize LPDDR5 RAM, but the 15T’s more modern chipset benefits from improved memory controller efficiency.

Battery Life

The Xiaomi 15T’s endurance rating of 57:44h significantly surpasses the Realme GT 5G’s 98h (though the GT’s rating is older and potentially less representative of current software/usage patterns). This difference is likely due to the Dimensity 8400 Ultra’s superior power efficiency. While the GT 5G charges slightly faster at 35 minutes (65W) compared to the 15T’s 50 minutes (67W), the 15T’s longer battery life and 1600 charge cycles offer a more compelling long-term value proposition. The inclusion of PD3.0 charging on the 15T also adds to its versatility.

Buying Guide

Buy the Xiaomi 15T if you prioritize all-day battery life, a vibrant and easily viewable display, and a more efficient processor for sustained performance. Buy the Realme GT 5G if you absolutely need the fastest possible charging speed (35 minutes vs 50 minutes) and are willing to trade off battery life and display quality for it. Gamers may also slightly prefer the GT 5G's Snapdragon 888, but thermal throttling could be a concern.

Frequently Asked Questions

❓ Does the Snapdragon 888 in the Realme GT 5G overheat during extended gaming sessions?
The Snapdragon 888 is known to generate significant heat under sustained load. While the Realme GT 5G likely incorporates cooling solutions, thermal throttling is a common occurrence, potentially reducing performance during prolonged gaming. The Xiaomi 15T’s Dimensity 8400 Ultra, built on a more efficient 4nm process, is less prone to overheating.
❓ How does the charging speed difference (35 minutes vs 50 minutes) impact daily use between the Realme GT 5G and Xiaomi 15T?
While the Realme GT 5G charges 15 minutes faster, the Xiaomi 15T’s significantly longer battery life mitigates the need for frequent top-ups. For most users, the convenience of a longer-lasting battery outweighs the slightly faster charging speed. The 15T also offers 1600 charge cycles, suggesting a longer lifespan for the battery itself.
❓ Is the difference in display brightness (650 nits vs 1525 nits) noticeable in everyday use?
Absolutely. The 1525 nits peak brightness of the Xiaomi 15T makes a dramatic difference in outdoor visibility, especially in direct sunlight. The Realme GT 5G’s 650 nits display will appear washed out in bright conditions, requiring users to seek shade or increase brightness, further impacting battery life.