BLU J4 vs UMIDIGI X

Network
2G network

GSM 850, 900, 1800, 1900

GSM 850, 900, 1800, 1900
3G network

HSDPA 850, 900, 1900, 2100

W-CDMA 800, 850, 900, 1700, 1900, 2100; TD-SCDMA 1880-1920, 2010-2025
4G network

-

LTE frequency band 1(2100), 2(1900), 3(1800), 4(1700/2100), 5(850), 7(2600), 8(900), 12(700), 13(700), 17(700), 18(800), 19(800), 26(850), 28(700), 38(2600), 40(2300), 41(2500), 66(1700/2100)
HSDPA speed

21.1 Mbps

-
HSUPA speed

5.76 Mbps

-
LTE speed

-

LTE Cat 7 301.5 Mbps download, 102 Mbps upload
GPRS

Yes

Yes
EDGE

Yes

Yes

Main camera
Camera type

Single

Triple
Main camera

8 MP

48 MP, f/1.79 , 1/2" , 1.6 µm
8 MP, 1/4" , 1.12 µm
5 MP
Primary camera resolution

-

8000 x 6000 pixels
Primary camera video

720p@30fps

1080@30fps
Primary camera flash

LED flash

dual LED flash
Camera features

-

Autofocus, continuous shooting, digital zoom, digital image stabilization, geotagging, panorama, HDR, touch focus, face detection, white balance settings, ISO settings, exposure compensation, self-timer, scene-mode

Connectivity
WLAN

Wi-Fi 802.11b, 802.11g, 802.11n

Wi-Fi 802.11a, 802.11b, 802.11g, 802.11n, 802.11n 5Ghz, 802.11ac
WLAN WiFi Hotspot

Yes

Yes
WLAN WiFi Direct

Yes

Yes
Wi-Fi display

-

Yes
WLAN WiFi Dual Band

-

Yes
USB

microUSB 2.0

Type-C reversible connector
USB On-The-Go

-

Yes
Bluetooth

v4.1

v4.2
Bluetooth A2DP

Yes

Yes
bluetooth HID

-

Yes
bluetooth LE

Yes

-
NFC

-

Yes
GPS

Yes, with A-GPS

Yes, with A-GPS
GLONASS

-

Yes
Beidou

-

Yes