TurboVS
LG 27U421A-B 27" specifications and in-depth review

LG 27U421A-B 27"

Manufacturer: LG

The LG 27U421A-B is a 27-inch monitor built around a VA-type LCD panel with LED backlighting, offering a glossy screen surface and wide 178-degree viewing angles both horizontally and vertically. With a 100Hz refresh rate and a 5ms response time, it is suited for everyday computing tasks where smooth on-screen motion matters. The display carries a curved form factor and supports portrait mode rotation, giving users some flexibility in how they set it up on a desk.

On the connectivity side, the LG 27U421A-B includes an HDMI 2.0 port, a USB Type-C input, one additional USB port, and a 3.5mm audio jack, while DisplayPort, VGA, and DVI connections are absent. The panel renders up to 16.7 million colors at a typical brightness of 250 nits, backed by a 3000:1 static contrast ratio. Power draw sits at 15W during operation and drops to 0.5W in standby. The monitor supports VESA mounting and tilt adjustment, though it lacks a swivel stand, built-in speakers, and adaptive sync technology.

Pros
  • Supports VESA mounting and portrait mode rotation, offering flexible placement and orientation options
  • Wide 178-degree viewing angles both horizontally and vertically ensure consistent image quality from various positions
  • Includes USB Type-C connectivity alongside HDMI 2.0, providing a broader range of device compatibility
  • 100Hz refresh rate delivers noticeably smoother motion than standard 60Hz panels
  • High 3000:1 contrast ratio characteristic of VA panels produces deep blacks and strong image depth
  • Supports color calibration, allowing users to adjust color output to their preference
Cons
  • Glossy panel with no anti-glare coating can cause reflections in brightly lit environments
  • Resolution of 1920x1080 on a 27-inch screen results in a relatively low pixel density of 81 ppi, which may appear soft at typical viewing distances
  • No adaptive synchronization support, which can lead to screen tearing during fast-moving content
  • No stereo speakers or audio output beyond a 3.5mm jack, requiring external audio hardware
  • Lacks a swivel stand, limiting horizontal adjustment without repositioning the entire unit
  • No DisplayPort output limits connection options for users with multi-monitor setups or DisplayPort-only hardware
Who is this for?

This monitor is a reasonable fit for everyday office work, casual browsing, and general home use, where its 100Hz refresh rate provides smoother visuals than standard displays without requiring high-end hardware. Users who need flexible setup options will appreciate the VESA mount support, portrait mode capability, and tilt adjustment. The USB Type-C input also makes it practical for those connecting modern laptops or devices with a single cable, while the 3000:1 contrast ratio suits users who consume video content or work in dimmer environments where deep blacks are noticeable.

Who is this NOT for?

This monitor is not well suited for professional photo or video editing, as the 1920x1080 resolution on a 27-inch panel yields a low pixel density of 81 ppi, which limits fine detail rendering and screen real estate. Users engaged in competitive gaming will find the lack of adaptive synchronization a drawback, as screen tearing can occur during fast-paced gameplay. Additionally, the glossy panel without anti-glare coating makes this a poor choice for use in brightly lit rooms or near windows, where reflections can significantly disrupt visibility.

Display:

Display type LED-backlit, LCD, VA
response time 5 ms
screen size 27"
resolution 1920 x 1080 px
pixel density 81 ppi
Adaptive synchronization None
has anti-glare coating ✕
refresh rate 100Hz
maximum horizontal viewing angle 178º
maximum vertical viewing angle 178º
has a matte panel ✕
has a glossy panel ✓
has a touch screen ✕

The display uses an LED-backlit LCD panel with a VA matrix, measuring 27 inches and rendering content at a 1920 x 1080 px resolution with a pixel density of 81 ppi. It operates at a 100Hz refresh rate with a 5ms response time, and the panel covers wide viewing angles of 178 degrees both horizontally and vertically. The screen has a glossy surface without an anti-glare coating, and it does not support touch input or adaptive synchronization technology.

General info:

Type Curved, Standard
supports total tilt ✓
Has a swivel stand ✕
Supports VESA mount ✓
height 360 mm
width 609 mm
thickness 43 mm
weight 3720 g
supports portrait mode ✓
volume 9427.32 cm³

This is a curved standard-type monitor with physical dimensions of 609 mm wide, 360 mm tall, and 43 mm thick, weighing 3720 g. It supports VESA mounting and can be tilted, and it is also capable of operating in portrait mode, though it does not include a swivel stand. The overall volume of the unit comes to 9427.32 cm³.

Colors:

brightness (typical) 250 nits
supports color calibration ✓
display colors 16.7 million
contrast ratio 3000:1

The panel delivers a typical brightness of 250 nits alongside a 3000:1 contrast ratio, which reflects the depth of blacks the VA panel can produce. It is capable of displaying 16.7 million colors and supports color calibration, allowing for adjustments to color output when needed.

Connectivity:

HDMI ports 1
supports Thunderbolt ✕
DisplayPort outputs 0
has a socket for a 3.5 mm audio jack ✓
has a DVI connector ✕
USB ports 1
Has USB Type-C ✓
HDMI version HDMI 2.0
supports Ethernet ✕
supports Wi-Fi ✕
has AirPlay ✕
mini DisplayPort outputs 0
has a VGA connector ✕

The monitor's connectivity options include one HDMI 2.0 port, one USB Type-C port, one additional USB port, and a 3.5mm audio jack. There are no DisplayPort, mini DisplayPort, DVI, or VGA outputs, and the monitor does not support Thunderbolt, Ethernet, Wi-Fi, or AirPlay.

Power:

operating power consumption 15W
standby power consumption 0.5W

During normal operation, the monitor draws 15W of power, while in standby mode consumption drops significantly to just 0.5W.

Features:

has PiP ✕
has stereo speakers ✕
has built-in smart TV ✕
has a remote control ✕
supports Dolby Digital ✕
supports Dolby Digital Plus ✕
has DTS Surround ✕
has an ambient light sensor ✕
has a front camera ✕

This monitor does not include built-in stereo speakers or any audio format support such as Dolby Digital, Dolby Digital Plus, or DTS Surround. It also lacks a front camera, ambient light sensor, remote control, Picture-in-Picture functionality, and built-in smart TV capabilities.

Final Verdict

The LG 27U421A-B is a 27-inch VA monitor that covers the essentials for everyday home and office use without overextending its feature set. Its 3000:1 contrast ratio and 100Hz refresh rate are genuine strengths at this screen size, and the inclusion of USB Type-C alongside VESA mount support adds practical versatility for modern setups. That said, the 1080p resolution begins to show its limits on a panel this large, and the absence of adaptive sync and an anti-glare coating narrows its appeal for more demanding users. Overall, the LG 27U421A-B is a straightforward, no-frills display that serves general computing and casual media consumption well, but users with more specialized needs in sharpness, gaming, or controlled lighting environments may find its specification set falls short.