Kyocera DuraForce vs Yezz Billy 4

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.

  • Weight

    Billy 4: 91 g lighter

    DuraForce:
    200 g
    Billy 4:
    109 g
  • Width

    Billy 4: 6.2 mm narrower

    DuraForce:
    70.6 mm
    Billy 4:
    64.4 mm
  • Screen diagonal

    Billy 4: 0.5 in smaller diagonal

    DuraForce:
    4.5 in
    Billy 4:
    4 in
  • Chipset

    DuraForce:
    Qualcomm MSM8928 Snapdragon 400 (28 nm)
    Billy 4:
    Qualcomm MSM8212 Snapdragon 200 (28 nm)
  • Depth

    Billy 4: 4.1 mm thinner

    DuraForce:
    14 mm
    Billy 4:
    9.9 mm
  • Height

    Billy 4: 14.4 mm shorter

    DuraForce:
    136.9 mm
    Billy 4:
    122.5 mm

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. DuraForce

    Height:
    136.9 mm +14.4 mm versus Billy 4
    Width:
    70.6 mm +6.2 mm versus Billy 4
    Depth:
    14 mm +4.1 mm versus Billy 4
  2. 2. Billy 4

    Height:
    122.5 mm
    Width:
    64.4 mm
    Depth:
    9.9 mm

Weight

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

  1. 1. DuraForce

    200 g

    +91 g versus Billy 4

  2. 2. Billy 4

    109 g

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. DuraForce

    Screen diagonal:
    4.5 in
    Aspect ratio (height:width):
    16:9
    Approximate rectangular screen area:
    55.8 cm²
  2. 2. Billy 4

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

DuraForce has approximately 22.6% more rectangular screen area than Billy 4.

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 DuraForce, Billy 4, compared at the same storage capacity.
StorageDuraForceBilly 4
16 GB 2 GB RAM Unknown
Billy 4: Original memory entry

4 GB · 512 MB RAM

Practical features

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

1. DuraForce

NFC:
Yes
Headphone jack:
Yes
Memory card support:
See details microSD · up to 32 GB (dedicated slot)

2. Billy 4

NFC:
Unknown
Headphone jack:
Yes
Memory card support:
See details microSD · up to 256 GB

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. DuraForce

    3100 mAh

    +1800 mAh versus Billy 4

  2. 2. Billy 4

    1300 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. DuraForce2. Billy 4

Everyday essentials
Everyday essentials — specifications for DuraForce, Billy 4.
SpecificationDuraForceBilly 4
Dimensions (HxWxD)
  • 136.9 Х 70.6 Х 14 mm
  • 122.5 Х 64.4 Х 9.9 mm
Weight
  • 200 g
  • 109 g
Technology
  • IPS LCD
  • TFT
Screen size
  • 4.5" inch
  • 4" inch
Screen resolution
  • 720 x 1280 px
  • 480 x 800 px
Internal memory Recorded storage / RAM variants. Entries are alternatives, not a combined maximum. Ambiguous formats stay as recorded.
  • 16 GB
  • 2 GB RAM
  • 4 GB
  • 512 MB RAM
Memory card support
  • microSD
  • up to 32 GB (dedicated slot)
  • microSD
  • up to 256 GB
Battery Capacity is not battery life. No endurance test is implied.
  • 3100 mAh
  • Non-removable Li-Ion
  • 1300 mAh
  • Removable Li-Ion
Operating system OS
  • Android 4.4.2 (KitKat)
  • Microsoft Windows Phone 8.1
Chipset
  • Qualcomm MSM8928 Snapdragon 400 (28 nm)
  • Qualcomm MSM8212 Snapdragon 200 (28 nm)
NFC
  • Yes
Unknown
Headphone jack
  • Yes
  • Yes
Display
Display — specifications for DuraForce, Billy 4.
SpecificationDuraForceBilly 4
Touchscreen
  • capacitive touchscreen
  • capacitive touchscreen
Display colors
  • 16M
  • 16M
Screen area
  • 55.8 cm2
  • 45.5 cm2
Screen format
  • 16:9 (height:width)
  • 5:3 (height:width)
Screen to body ratio
  • 57.8%
  • 57.7%
PPI /points per inch/
  • 326 PPI
  • 233 PPI
Screen protection
  • Yes
Unknown
Camera and Video
Camera and Video — specifications for DuraForce, Billy 4.
SpecificationDuraForceBilly 4
Rear camera, main
  • 8 MP
  • Single
  • 8 MP
  • Single
Camera specs
  • 8 MP
  • AF
  • 8 MP
  • AF
Functions
  • LED flash
  • HDR
  • panorama
  • LED flash
Video
  • 1080p@30fps
  • 720p@30fps
Front camera, selfie
  • 2 MP
  • Single
  • 1.3 MP
  • Single
Specifications
  • 2 MP
  • 1.3 MP
Performance

Scores marked * are historical catalogue entries. Test conditions are unspecified; no new testing is implied.

Performance — specifications for DuraForce, Billy 4.
SpecificationDuraForceBilly 4
Processor CPU
  • Quad-core 1.4 GHz Cortex-A7
  • Quad-core 1.2 GHz Cortex-A7
Graphics processor GPU
  • Adreno 305
  • Adreno 302
Antutu 7 score *
  • 19579
Unknown
General specs
General specs — specifications for DuraForce, Billy 4.
SpecificationDuraForceBilly 4
Release date
  • 2014
  • November
  • 2014
  • June
Colors
  • Black
  • White
  • Black
  • Red
  • Gun Metal
  • Blue
  • Yellow
  • Champing Gold
Historical recorded price Legacy catalogue value; date unknown. Not a current offer.
  • 320 EUR
Unknown
Battery life
  • Stand by time- Up to 504 h Talking time- Up to 17 h
  • Stand by time- Up to 350 h (2G) / Up to 300 h (3G) Talking time- Up to 7 h (2G) / Up to 4 h 30 min (3G)
Communication and Connectivity
Communication and Connectivity — specifications for DuraForce, Billy 4.
SpecificationDuraForceBilly 4
SIM card
  • Nano-SIM
  • Dual SIM (Micro-SIM)
Network
  • Show all network frequencies: -2G - GSM 850 / 900 / 1800 / 1900 -3G - HSDPA 850 / 900 / 1900 / 2100 -4G - LTE band 1(2100)
  • 2(1900)
  • 4(1700/2100)
  • 5(850)
  • 7(2600)
  • 17(700)
  • Show all network frequencies: -2G - GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2
Speed
  • HSPA 42.2/5.76 Mbps
  • LTE Cat4 150/50 Mbps
  • HSPA 42.2/5.76 Mbps
GPRS
  • Yes
  • Class 12
Edge
  • Yes
  • Class 12
Wi-Fi
  • Wi-Fi 802.11 a/b/g/n/ac
  • dual-band
  • hotspot
  • Wi-Fi 802.11 a/b/g/n
  • dual-band
  • hotspot
GPS
  • Yes
  • with A-GPS
  • Yes
  • with A-GPS
  • GLONASS
USB
  • microUSB 2.0
  • microUSB 2.0
Bluetooth
  • 4.0
  • A2DP
  • EDR
  • LE
  • 4.0
  • A2DP
Music and Audio
Music and Audio — specifications for DuraForce, Billy 4.
SpecificationDuraForceBilly 4
Radio
  • No
  • Stereo FM radio
Others
  • Smart Sonic Receiver -Active noise cancellation with dedicated mic
Unknown
Other features
Other features — specifications for DuraForce, Billy 4.
SpecificationDuraForceBilly 4
Dop
  • Sensors Accelerometer
  • proximity
  • compass
  • barometer - IP68 dust/water proof (up to 1.5m for 30 mins) -MIL-STD-810G compliant - For AT&T
  • U.S. Cellular & Bell Canada
  • Sensors Accelerometer
  • proximity