Background and Identification

The vivo X21 Android smartphone was released by vivo in March 2018. vivo Communication Technology Co, Ltd. is a technology company that produces and designs smartphones, software, smartphone accessories, and online services. vivo is owned by BBK Electronics, a Chinese conglomerate that specializes in electronics. vivo was founded in China in 2009. The X21 model was released in black, white, and red body colors.

The vivo X21 smartphone includes a 6.28-inch display with a resolution of 1080 by 2280 pixels. The phone includes a scratch-resistant glass front and aluminum back and frame. It features hybrid Dual-SIM capabilities, meaning it can hold two Nano-SIM cards and use one while the other card is in standby. The X21 comes with 6 GB of RAM and either 64 GB or 128 GB of internal storage. It features dual 12-megapixel and 5-megapixel main cameras and a single 12-megapixel selfie camera. The X21 also includes a 3200 mAh non-removable battery (a non-removable battery is one whose adhesive is permanent, making repair and replacement difficult).

vivo phones can be identified by the name “vivo” in lowercase letters in the top center of the phone’s back. The rear-mounted fingerprint sensor is located above the “vivo” name and the phone’s dual main cameras are positioned in the top left-hand corner of the phone’s back.

Technical Specifications

Models: 1725, X21A

Release date: March 2018

Body:

  • Dimensions and Weight: 154.5 x 74.8 x 7.4 mm (6.08 x 2.94 x 0.29 in), 156.2 g (5.50 oz)
  • Build: Glass front (Gorilla Glass 3), aluminum back, aluminum frame
  • SIM: Hybrid Dual SIM (Nano-SIM, dual stand-by)

Display:

  • Type: Super AMOLED capacitive touchscreen, 16M colors
  • Size: 6.28 inches, 98.4 cm2 (~85.2% screen-to-body ratio)
  • Resolution: 1080 x 2280 pixels, 19:9 ratio (~402 ppi density)
  • Protection: Corning Gorilla Glass 3

Platform:

  • OS: Android 8.1 (Oreo), Funtouch 4
  • Chipset: Qualcomm SDM660 Snapdragon 660 (14 nm)
  • CPU: Octa-core (4x2.2 GHz Kryo 260 Gold & 4x1.8 GHz Kryo 260 Silver)
  • GPU: Adreno 512

Memory:

  • Card slot:microSDXC (uses shared SIM slot)
  • Internal: 64GB 6GB RAM, 128GB 6GB RAM
  • eMMC 5.1

Main Camera:

  • Dual:
    • 12 MP, f/1.8, 1/2.55", 1.4µm, dual pixel PDAF
    • 5 MP, f/2.4, (depth)
  • Features: LED flash, HDR, panorama
  • Video: 1080p@30fps

Selfie Camera:

  • Single: 12 MP, f/2.0, (wide), 1/2.8", 1.28µm
  • Video: 1080p@30fps

Sound:

  • Loudspeaker: Yes
  • 3.5 mm jack: Yes
  • 32-bit/192kHz audio

Communications:

  • WLAN: Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct, hotspot
  • Bluetooth: 5.0, A2DP, LE
  • GPS: Yes, with A-GPS, GLONASS
  • Radio: FM radio
  • USB: MicroUSB 2.0, USB On-The-Go

Features:

  • Sensors: Fingerprint (rear-mounted), accelerometer, proximity, compass

Battery:

  • Li-Ion 3200 mAh, non-removable
  • Charging: Fast charging 18W

Miscellaneous:

  • Colors: Black, Aurora White, Ruby Red

Additional Information