Allview E4 vs vivo X21 UD

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.

• Display technology

  OLED versus LCD

  E4:

  LCD

  X21 UD:

  OLED

• Weight

  E4: 26.2 g lighter

  E4:

  130 g

  X21 UD:

  156.2 g

• Width

  E4: 4.6 mm narrower

  E4:

  70.2 mm

  X21 UD:

  74.8 mm

• Screen diagonal

  E4: 0.78 in smaller diagonal

  E4:

  5.5 in

  X21 UD:

  6.28 in

• Chipset

  E4:

  Mediatek MT6753 (28 nm)

  X21 UD:

  Qualcomm SDM660 Snapdragon 660 (14 nm)

• Rear camera layout

  E4:

  Single

  X21 UD:

  Dual

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. E4

   Height:

   140.7 mm

   Width:

   70.2 mm

   Depth:

   8.6 mm +1.2 mm versus X21 UD

2. 2. X21 UD

   Height:

   154.5 mm +13.8 mm versus E4

   Width:

   74.8 mm +4.6 mm versus E4

   Depth:

   7.4 mm

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.

At least two phones need compatible screen dimensions for a drawing.

1. 1. E4

   E4: Screen geometry unavailable or conflicting.

2. 2. X21 UD

   Screen diagonal:

   6.28 in

   Aspect ratio (height:width):

   19:9

   Approximate rectangular screen area:

   98.4 cm²

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.

Practical features

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

Battery capacity

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

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.