Screen size
iQOO Z11xWinner: 6.8"+7.1%
X21 UD6.3"
Quick verdict
iQOO Z11x leads the measured specs 13-5.
Measured wins
iQOO Z11x
13
spec wins
Overall winner
Ties
5
equal specs
X21 UD
5
spec wins
Screen size
Technology
iQOO Z11x
GSM / HSPA / LTE / 5G
X21 UD
GSM / CDMA / HSPA / LTE
2G bands
iQOO Z11x
GSM 850 / 900 / 1800 / 1900
X21 UD
GSM 850 / 900 / 1800 / 1900 , CDMA 800 & TD-SCDMA
3G bands
iQOO Z11x
HSDPA 850 / 900 / 2100
X21 UD
HSDPA 850 / 900 / 1900 / 2100
4G bands
iQOO Z11x
1, 3, 5, 8, 28, 38, 40, 41
Resolution
Refresh rate
Peak brightness
Pixel density
CPU speed
RAM
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
SD card
Stereo speakers
X21 UD
1, 2, 3, 5, 8, 34, 38, 39, 40, 41
5G bands
iQOO Z11x
1, 3, 5, 8, 28, 38, 40, 41, 77, 78 SA/NSA
X21 UD
-
Speed
iQOO Z11x
HSPA, LTE, 5G
X21 UD
HSPA 42.2/5.76 Mbps, LTE (2CA) Cat6 300/50 Mbps
Announced
iQOO Z11x
2026, March 12
X21 UD
2018, March. Released 2018, March
Status
iQOO Z11x
Released Mar 2026
X21 UD
Discontinued
Dimensions
iQOO Z11x
166.6 x 78.4 x 8.4 mm (6.56 x 3.09 x 0.33 in)
X21 UD
154.5 x 74.8 x 7.4 mm (6.08 x 2.94 x 0.29 in)
Weight
iQOO Z11x
219 g (7.72 oz)
X21 UD
156.2 g (5.50 oz)
Build
iQOO Z11x
Glass front, plastic frame, plastic back
X21 UD
Glass front (Gorilla Glass 3), aluminum back, aluminum frame
SIM
iQOO Z11x
Nano-SIM + Nano-SIM
X21 UD
Nano-SIM + Nano-SIM
Other
iQOO Z11x
IP68/IP69 dust tight and water resistant (high pressure water jets; immersible up to 1.5m for 30 min)
X21 UD
-
Type
iQOO Z11x
IPS LCD, 120Hz, 1200 nits (HBM)
X21 UD
Super AMOLED
Size
iQOO Z11x
6.76 inches, 112.1 cm2 (~85.8% screen-to-body ratio)
X21 UD
6.28 inches, 98.4 cm2 (~85.2% screen-to-body ratio)
Resolution
iQOO Z11x
1080 x 2344 pixels, 19.5:9 ratio (~382 ppi density)
X21 UD
1080 x 2280 pixels, 19:9 ratio (~402 ppi density)
Protection
iQOO Z11x
-
X21 UD
Corning Gorilla Glass 3
OS
iQOO Z11x
Android 16, OriginOS 6
X21 UD
Android 8.1 (Oreo), Funtouch 4
Chipset
iQOO Z11x
Mediatek Dimensity 7400 Turbo (4 nm)
X21 UD
Qualcomm SDM660 Snapdragon 660 (14 nm)
CPU
iQOO Z11x
Octa-core (4x2.6 GHz Cortex-A78 & 4x2.0 GHz Cortex-A55)
X21 UD
Octa-core (4x2.2 GHz Kryo 260 Gold & 4x1.8 GHz Kryo 260 Silver)
GPU
iQOO Z11x
Mali-G615 MC2
X21 UD
Adreno 512
Card slot
iQOO Z11x
No
X21 UD
microSDXC (uses shared SIM slot)
Internal
iQOO Z11x
128GB 6GB RAM, 128GB 8GB RAM, 256GB 8GB RAM
X21 UD
128GB 6GB RAM
Other
iQOO Z11x
UFS 3.1
X21 UD
eMMC 5.1
Dual
iQOO Z11x
50 MP, (wide), 1/2.93", PDAF Auxiliary lens
X21 UD
12 MP, f/1.8, 1/2.55", 1.4µm, dual pixel PDAF Auxiliary lens
Features
iQOO Z11x
LED flash, HDR, panorama
X21 UD
LED flash, HDR, panorama
Video
iQOO Z11x
4K@30fps, 1080p@30fps, gyro-EIS
X21 UD
1080p@30fps
Single
iQOO Z11x
32 MP, (wide)
X21 UD
12 MP, f/2.0, (wide), 1/2.8", 1.28µm
Video
iQOO Z11x
4K@30fps, 1080p@30fps
X21 UD
1080p@30fps
Loudspeaker
iQOO Z11x
Yes, with stereo speakers
X21 UD
Yes
3.5mm jack
iQOO Z11x
No
X21 UD
Yes
Other
iQOO Z11x
-
X21 UD
32-bit/192kHz Hi-Res audio
WLAN
iQOO Z11x
Wi-Fi 802.11 a/b/g/n/ac, dual-band
X21 UD
Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct
Bluetooth
iQOO Z11x
5.4, A2DP, LE
X21 UD
5.0, A2DP, LE
Positioning
iQOO Z11x
GPS, GALILEO, GLONASS, BDS, QZSS
X21 UD
GPS, GLONASS
NFC
iQOO Z11x
No
X21 UD
No
Radio
iQOO Z11x
No
X21 UD
FM radio
USB
iQOO Z11x
USB Type-C 2.0, OTG
X21 UD
microUSB 2.0, OTG
Sensors
iQOO Z11x
Fingerprint (side-mounted), accelerometer, gyro, proximity, compass
X21 UD
Fingerprint (under display, optical), accelerometer, proximity, compass
Type
iQOO Z11x
Si/C Li-Ion 7200 mAh
X21 UD
Li-Ion 3200 mAh, non-removable
Charging
iQOO Z11x
44W wired, PPS, 50% in 43 min Reverse wired Bypass Charging
X21 UD
18W wired
Colors
iQOO Z11x
Prismatic Green, Titan Black
X21 UD
Black, Ruby Red
Models
iQOO Z11x
I2507
X21 UD
X21UD A
Price
iQOO Z11x
-
X21 UD
About 550 EUR