BLU J4 vs T-Mobile Sidekick LX

Compare recorded specifications, size and practical differences.

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Key differences

Calculated from recorded specifications using minimum difference thresholds. These are differences, not an overall ranking. For three phones, numeric highlights compare the two extremes.

  • Width

    Sidekick LX: 12.3 mm narrower

    J4:
    72.3 mm
    Sidekick LX:
    60 mm
  • Screen diagonal

    Sidekick LX: 2.5 in smaller diagonal

    J4:
    5.5 in
    Sidekick LX:
    3 in
  • Depth

    J4: 12 mm thinner

    J4:
    10 mm
    Sidekick LX:
    22 mm
  • Height

    Sidekick LX: 21.5 mm shorter

    J4:
    151 mm
    Sidekick LX:
    129.5 mm
  • Release year

    J4:
    2019
    Sidekick LX:
    2007

Physical size

Relative size, not calibrated actual size. Front and side outlines share one scale and a bottom baseline. Generic outlines use recorded body dimensions, excluding camera bumps.

  1. 1. J4

    Height:
    151 mm +21.5 mm versus Sidekick LX
    Width:
    72.3 mm +12.3 mm versus Sidekick LX
    Depth:
    10 mm
  2. 2. Sidekick LX

    Height:
    129.5 mm
    Width:
    60 mm
    Depth:
    22 mm +12 mm versus J4

Weight

Bars start at zero and share a scale within this chart.

  1. 1. J4

    158 g

  2. 2. Sidekick LX

    162 g

    +4 g versus J4

Screen size

Approximate rectangular screens calculated from recorded diagonal and aspect ratio at one relative scale. Rounded corners and cutouts are not subtracted. These are not phone outlines or calibrated actual sizes.

  1. 1. J4

    Screen diagonal:
    5.5 in
    Aspect ratio (height:width):
    18:9
    Approximate rectangular screen area:
    78.1 cm²
  2. 2. Sidekick LX

    Screen diagonal:
    3 in
    Aspect ratio (height:width):
    5:3
    Approximate rectangular screen area:
    25.6 cm²

J4 has approximately 204.7% more rectangular screen area than Sidekick LX.

Memory variants

Each row compares the same storage capacity. Cells show recorded RAM alternatives, not combined maxima. Not recorded does not mean unavailable in every market.

Recorded RAM for J4, Sidekick LX, compared at the same storage capacity.
StorageJ4Sidekick LX
32 GB 1 GB RAM Unknown
Sidekick LX: Original memory entry

64 MB RAM · 64 MB ROM

Practical features

Explicit Yes and No values are shown directly. Qualified or regional records retain their details. Unknown means the record is missing.

1. J4

NFC:
Unknown
Headphone jack:
Yes
Memory card support:
See details microSDXC

2. Sidekick LX

NFC:
Unknown
Headphone jack:
No
Memory card support:
See details microSD (dedicated slot)

Battery capacity

Capacity is not battery life. No endurance test is implied.

Recorded battery capacity

Bars start at zero and share a scale within this chart.

  1. 1. J4

    2200 mAh

    +660 mAh versus Sidekick LX

  2. 2. Sidekick LX

    1540 mAh

Specifications

Open a section for more detail. On narrow screens, swipe sideways or use Left/Right arrow keys while the table is focused. Unknown means missing data, not No. Recorded zero values are shown as recorded.

1. J42. Sidekick LX

Everyday essentials
Everyday essentials — specifications for J4, Sidekick LX.
SpecificationJ4Sidekick LX
Dimensions (HxWxD)
  • 151 Х 72.3 Х 10 mm
  • 129.5 Х 60 Х 22 mm
Weight
  • 158 g
  • 162 g
Technology
  • IPS LCD
  • TFT
Screen size
  • 5.5" inch
  • 3" inch
Screen resolution
  • 720 x 1440 px
  • 240 x 400 px
Internal memory Recorded storage / RAM variants. Entries are alternatives, not a combined maximum. Ambiguous formats stay as recorded.
  • 32GB 1GB RAM
  • 64 MB RAM
  • 64 MB ROM
Memory card support
  • microSDXC
  • microSD (dedicated slot)
Battery Capacity is not battery life. No endurance test is implied.
  • 2200 mAh
  • Removable Li-Po
  • 1540 mAh
  • Removable Li-Ion
Operating system OS
  • Android 8.1 Oreo (Go edition)
  • Danger OS
Headphone jack
  • Yes
  • No
Display
Display — specifications for J4, Sidekick LX.
SpecificationJ4Sidekick LX
Touchscreen
  • capacitive touchscreen
Unknown
Display colors
  • 16M
  • 65K
Screen area
  • 78.1 cm2
  • 25.6 cm2
Screen format
  • 18:9 (height:width)
  • 5:3 (height:width)
Screen to body ratio
  • 71.5%
  • 33.0%
PPI /points per inch/
  • 293 PPI
  • 155 PPI
Camera and Video
Camera and Video — specifications for J4, Sidekick LX.
SpecificationJ4Sidekick LX
Rear camera, main
  • 8 MP
  • Single
  • 1.3 MP
  • Single
Camera specs
  • 8 MP
  • AF
  • 1.3 MP
Functions
  • LED flash
Unknown
Video
  • 720p@30fps
  • Yes
Front camera, selfie
  • 8 MP
  • Single
  • 0 MP,
Specifications
  • 8 MP
Unknown
Performance
Performance — specifications for J4, Sidekick LX.
SpecificationJ4Sidekick LX
Processor CPU
  • Quad-core 1.3 GHz Cortex-A7
Unknown
Graphics processor GPU
  • Mali-400
Unknown
General specs
General specs — specifications for J4, Sidekick LX.
SpecificationJ4Sidekick LX
Release date
  • 2019
  • October
  • 2007
  • September
Colors
  • Blue
  • Black
  • Brown
  • Black
Historical recorded price Legacy catalogue value; date unknown. Not a current offer.
  • 70 EUR
  • 160 EUR
Battery life Unknown
  • Stand by time- Up to 96 h Talking time- Up to 6 h 50 min
Communication and Connectivity
Communication and Connectivity — specifications for J4, Sidekick LX.
SpecificationJ4Sidekick LX
SIM card
  • Dual SIM (Nano-SIM
  • dual stand-by)
  • Mini-SIM
Network
  • Show all network frequencies: -2G - GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2
Unknown
Speed
  • HSPA 21.1/5.76 Mbps
Unknown
GPRS
  • Yes
  • Class 10
Edge
  • Yes
  • Class 10
Wi-Fi
  • Wi-Fi 802.11 b/g/n
  • Wi-Fi Direct
  • hotspot
  • No
GPS
  • Yes
  • with A-GPS
  • No
USB
  • microUSB 2.0
  • Proprietary
Bluetooth
  • 4.1
  • A2DP
  • LE
  • 2.0
Harmful irradiation Unknown
  • SAR - 0.40 W/kg (head) 0.46 W/kg (body)
Music and Audio
Music and Audio — specifications for J4, Sidekick LX.
SpecificationJ4Sidekick LX
Radio
  • FM radio
  • No
Other features
Other features — specifications for J4, Sidekick LX.
SpecificationJ4Sidekick LX
Dop
  • Sensors Accelerometer For USA
  • MP3/WMA audio player -MP4 player -Voice memo