Oppo A91
#2191
vivo X21 UD
#2702Category Breakdown
Oppo A91
vivo X21 UD
Performance
80.279.6
Camera
45.519.1
Display
76.682.8
Battery
29.025.7
Build
73.076.2
Connectivity
56.759.3
Audio
8.98.9
Overall
51.046.8
Summary
- The Oppo A91 features a larger 6.4-inch AMOLED display compared to the 6.28-inch Super AMOLED on the vivo X21 UD, both offering similar resolutions and refresh rates.
- In terms of performance, the A91 is powered by the Mediatek Helio P70, while the X21 UD uses the Qualcomm Snapdragon 660, with the A91 having a slight edge in CPU performance.
- The A91's camera system includes a 48 MP main sensor, significantly outperforming the X21 UD's 12 MP setup, although both can record 1080p video.
- The A91 also has a larger 4025 mAh battery versus the 3200 mAh in the X21 UD, providing better longevity.
- In terms of software, the A91 runs on a more recent Android version, ColorOS 11, compared to the older Funtouch 4 on the X21 UD.
- Build quality favors the X21 UD with its aluminum frame and back, while the A91 uses plastic for its back and frame.
Side-by-side Specification Comparison
Oppo A91
vivo X21 UD
General
Release Date
2019
2018
Announced
2019, December 20
2018
Description
Versions: CPH2001, CPH2021 (International); PCPM00 (China)
N/A
Display
Size
6.4"
6.28"
Type
AMOLED, 430 nits (typ)
Super AMOLED
Resolution
1080 x 2400 pixels, 20:9 ratio (~408 ppi density)
1080 x 2280 pixels, 19:9 ratio (~402 ppi density)
PPI
1080
1080
Refresh Rate
60Hz
60Hz
HDR Support
✗
✗
Protection
Corning Gorilla Glass 5
Corning Gorilla Glass 3
Performance
Chipset
Mediatek MT6771V Helio P70 (12 nm)
Qualcomm SDM660 Snapdragon 660 (14 nm)
CPU
Octa-core (4x2.1 GHz Cortex-A73 & 4x2.0 GHz Cortex-A53)
Octa-core (4x2.2 GHz Kryo 260 Gold & 4x1.8 GHz Kryo 260 Silver)
GPU
Mali-G72 MP3
Adreno 512
Memory
128GB 4GB RAM, 128GB 8GB RAM, 256GB 8GB RAM
128GB 6GB RAM
Expandable Storage
✗
✗
Card Slot
microSDXC (dedicated slot)
microSDXC (uses shared SIM slot)
Camera
Main Camera
48 MP, f/1.8, 26mm (wide), 1/2.0", 0.8µm, PDAF8 MP, f/2.3, 119˚ (ultrawide), 1/4.0", 1.12µm2 MP B/W, f/2.4, 1/5.0", 1.75µm2 MP, f/2.4, (depth)
12 MP, f/1.8, 1/2.55", 1.4µm, dual pixel PDAF5 MP, f/2.4, (depth)
Main Camera Features
LED flash, HDR, panorama
LED flash, HDR, panorama
Front Camera
16 MP, f/2.0, 26mm (wide), 1/3.06", 1.0µm
12 MP, f/2.0, (wide), 1/2.8", 1.28µm
Front Camera Features
HDR
N/A
Video Recording
1080p@30fps, gyro-EIS
1080p@30fps
Selfie Video
1080p@30fps
1080p@30fps
Optical Stabilization
✗
✗
Night Mode
✗
✗
Raw Photo Support
✗
✗
Battery
Capacity
4025 mAh
3200 mAh
Battery Details
Li-Po 4025 mAh, non-removable
Li-Ion 3200 mAh, non-removable
Charging Details
20W wired, 50% in 30 min
18W wired
Fast Charging
✗
✗
Wireless Charging
✗
✗
Build & Safety
Dimensions
160.2 x 73.3 x 7.9 mm (6.31 x 2.89 x 0.31 in)
154.5 x 74.8 x 7.4 mm (6.08 x 2.94 x 0.29 in)
Weight
172 g
156.2 g
Materials
Glass front (Gorilla Glass 5), plastic back, plastic frame
Glass front (Gorilla Glass 3), aluminum back, aluminum frame
Colors
Lightening Black, Unicorn White, Blazing Blue, Red
Black, Ruby Red
Foldable
✗
✗
SAR
N/A
N/A
Connectivity
SIM
Nano-SIM + Nano-SIM
Nano-SIM + Nano-SIM
Network
GSM / CDMA / HSPA / LTE
GSM / CDMA / HSPA / LTE
Network Speed
HSPA, LTE
HSPA 42.2/5.76 Mbps, LTE (2CA) Cat6 300/50 Mbps
5G
✗
✗
4G
✓
✓
WiFi
Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct
Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct
Bluetooth
4.2, A2DP, LE
5.0, A2DP, LE
NFC
✗
✗
USB
USB Type-C 2.0, OTG
microUSB 2.0, OTG
IR Blaster
✗
✗
Headphone Jack
✓
✓
Radio
✗
✗
Positioning
GPS, GLONASS, BDS
GPS, GLONASS
Audio
Stereo Speakers
✗
✗
Loudspeaker
Yes
Yes
Audio Jack
Yes
Yes
Software & Security
Operating System
Android 9.0 (Pie), upgradable to Android 11, ColorOS 11
Android 8.1 (Oreo), Funtouch 4
Fingerprint
✓
✓
Face Unlock
✗
✗
Sensors
Fingerprint (under display, optical), accelerometer, gyro, proximity, compass
Fingerprint (under display, optical), accelerometer, proximity, compass