Screen size
X21 UD6.3"
Y6tWinner: 6.7"+6.8%
Quick verdict
Y6t leads the measured specs 9-6.
Measured wins
X21 UD
6
spec wins
Ties
8
equal specs
Y6t
9
spec wins
Overall winner
Screen size
Technology
X21 UD
GSM / CDMA / HSPA / LTE
Y6t
GSM / HSPA / LTE / 5G
2G bands
X21 UD
GSM 850 / 900 / 1800 / 1900 , CDMA 800 & TD-SCDMA
Y6t
GSM 850 / 900 / 1800 / 1900
3G bands
X21 UD
HSDPA 850 / 900 / 1900 / 2100
Y6t
HSDPA 850 / 900 / 2100
4G bands
X21 UD
1, 2, 3, 5, 8, 34, 38, 39, 40, 41
Resolution
Refresh rate
Peak brightness
Pixel density
CPU speed
equal specsRAM
equal specsStorage
equal specsMain camera
Front camera
Battery
Wired charging
Weight
Thickness
IP rating
Wi‑Fi
Bluetooth
equal specsUSB
equal specs5G support
NFC
equal specs3.5mm jack
equal specsSD card
equal specsStereo speakers
Y6t
1, 3, 4, 5, 8, 28, 34, 38, 39, 40, 41, 66
Speed
X21 UD
HSPA 42.2/5.76 Mbps, LTE (2CA) Cat6 300/50 Mbps
Y6t
HSPA, LTE, 5G
5G bands
X21 UD
-
Y6t
1, 3, 5, 8, 28, 38, 40, 41, 77, 78 SA/NSA
Announced
X21 UD
2018, March. Released 2018, March
Y6t
2026, April 20
Status
X21 UD
Discontinued
Y6t
Available. Released 2026, April 27
Dimensions
X21 UD
154.5 x 74.8 x 7.4 mm (6.08 x 2.94 x 0.29 in)
Y6t
167.4 x 77.1 x 8.4 mm (6.59 x 3.04 x 0.33 in)
Weight
X21 UD
156.2 g (5.50 oz)
Y6t
209 g (7.37 oz)
Build
X21 UD
Glass front (Gorilla Glass 3), aluminum back, aluminum frame
Y6t
Glass front, plastic frame, plastic back
SIM
X21 UD
Nano-SIM + Nano-SIM
Y6t
Nano-SIM + Nano-SIM
Other
X21 UD
-
Y6t
IP65 dust tight and water resistant (low pressure water jets) MIL-STD-810H compliant* * does not guarantee ruggedness or use in extreme conditions
Type
X21 UD
Super AMOLED
Y6t
IPS LCD, 120Hz, 1200 nits (HBM)
Size
X21 UD
6.28 inches, 98.4 cm2 (~85.2% screen-to-body ratio)
Y6t
6.74 inches, 109.7 cm2 (~85.0% screen-to-body ratio)
Resolution
X21 UD
1080 x 2280 pixels, 19:9 ratio (~402 ppi density)
Y6t
720 x 1600 pixels, 20:9 ratio (~260 ppi density)
Protection
X21 UD
Corning Gorilla Glass 3
Y6t
-
OS
X21 UD
Android 8.1 (Oreo), Funtouch 4
Y6t
Android 16, OriginOS 6
Chipset
X21 UD
Qualcomm SDM660 Snapdragon 660 (14 nm)
Y6t
Qualcomm SM4450 Snapdragon 4 Gen 2 (4 nm)
CPU
X21 UD
Octa-core (4x2.2 GHz Kryo 260 Gold & 4x1.8 GHz Kryo 260 Silver)
Y6t
Octa-core (2x2.2 GHz Cortex-A78 & 6x1.95 GHz Cortex-A55)
GPU
X21 UD
Adreno 512
Y6t
Adreno 613
Card slot
X21 UD
microSDXC (uses shared SIM slot)
Y6t
microSDXC (dedicated slot)
Internal
X21 UD
128GB 6GB RAM
Y6t
128GB 6GB RAM, 128GB 8GB RAM, 256GB 6GB RAM
Other
X21 UD
eMMC 5.1
Y6t
UFS 3.1
Dual
X21 UD
12 MP, f/1.8, 1/2.55", 1.4µm, dual pixel PDAF Auxiliary lens
Y6t
-
Features
X21 UD
LED flash, HDR, panorama
Y6t
LED flash, panorama
Video
X21 UD
1080p@30fps
Y6t
1080p@30fps
Single
X21 UD
-
Y6t
13 MP, f/2.2, (wide), AF
Single
X21 UD
12 MP, f/2.0, (wide), 1/2.8", 1.28µm
Y6t
5 MP, f/2.2, (wide)
Video
X21 UD
1080p@30fps
Y6t
1080p@30fps
Loudspeaker
X21 UD
Yes
Y6t
Yes, with stereo speakers
3.5mm jack
X21 UD
Yes
Y6t
Yes
Other
X21 UD
32-bit/192kHz Hi-Res audio
Y6t
-
WLAN
X21 UD
Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct
Y6t
Wi-Fi 802.11 a/b/g/n/ac, dual-band
Bluetooth
X21 UD
5.0, A2DP, LE
Y6t
5.1, A2DP, LE, aptX HD, aptX Adaptive
Positioning
X21 UD
GPS, GLONASS
Y6t
GPS, GALILEO, GLONASS, BDS, QZSS
NFC
X21 UD
No
Y6t
No
Radio
X21 UD
FM radio
Y6t
Unspecified
USB
X21 UD
microUSB 2.0, OTG
Y6t
USB Type-C 2.0, OTG
Infrared port
X21 UD
-
Y6t
Yes
Sensors
X21 UD
Fingerprint (under display, optical), accelerometer, proximity, compass
Y6t
Fingerprint (side-mounted), accelerometer, proximity, compass
Type
X21 UD
Li-Ion 3200 mAh, non-removable
Y6t
Li-Ion 6500 mAh
Charging
X21 UD
18W wired
Y6t
15W wired Reverse wired
Colors
X21 UD
Black, Ruby Red
Y6t
Black, Blue, Gold
Models
X21 UD
X21UD A
Y6t
V2559A
Price
X21 UD
About 550 EUR
Y6t
About 210 EUR