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You’re in front of your monitor for hours on end. Make the most of your time, with an LG Full HD LED monitor. The clarity of 1080p pixel resolution is a game-changer. Simply put, everything looks more detailed than standard HD.
With FreeSync*, gamers can experience seamless, fluid movement throughout hi-res, fast-paced games. FreeSync virtually eliminates screen tearing and stuttering.
*FreeSync is only available when it is connected to Display Port or HDMI.
Dynamic Action Sync
Minimize input lag with Dynamic Action Sync so you can catch every single moment in real-time.
Keep visibility even in dark scenes. LG's Black Stabilizer senses dark scenes and helps make it brighter so that you can find the enemies hiding and waiting to attack your player in the dark.
On-Screen Control puts a host of essential monitor settings into a handy window for quick, easy access. Volume, brightness, picture mode presets, Screen Split 2.0 and Dual Controller and more can now be adjusted with just a few clicks of the mouse, instead of hard buttons on the monitor.
Software download required to enable OnScreen Control. For download details, visit LGUSA.com/OnScreenControlSupport
This monitor gives you the freedom to take it off the desk and hang it on the wall. Liberate your viewing options and save desktop space with this wall-mountable LG monitor.
Mounting hardware not included.
ENERGY STAR® certified monitors meet stringent energy efficiency requirements set by the US Environmental Protection Agency in On, Sleep, and Off Modes. On average, monitors that have earned the ENERGY STAR® are 25% more energy efficient than standard options.
Custom, Reader, Color Weakness, Photo, Cinema, Game
Plug & Play
Response Time Control
OnScreen Control (OSC)
R/G/B Color Control
Auto Adjustment(D-sub Only)
1 Year Parts & Labor
Screen Size Class (diagonal)
Pixel Pitch (mm)
0.31125 x 0.31125
1920 x 1080
300(Typ), 240(min) cd/m2
Contrast Ratio (DFC)
Anti glare ,3H
Wall mount size (mm)
100 x 100
Easy Setup Guide
S/W Install CD
No built-in speaker
What people are saying
Rated 4 out of
Good monitorBought this monitor a week ago, and have been pleased.
Date published: 2019-11-09
Rated 5 out of
Great Bright Screen!!I bought this Monitor about a month ago, it has been an amazing experience. Just ready to go as soon as I power it on. The bright vibrant colors, just a magical experience. Excellent for business or just to have a little fun surfing the Web. NO regrets here!!!! Highly recommended!! Thanks LG!!!!
Date published: 2019-11-04
Rated 4 out of
good valueFor the price its a good value, would be nice if it had internal speakers but I knew it didn't when I bought it
Ask your questions. Share your answers. Please review the detailed product information and help guides in the Product Support section for this product prior to posting a question.
Where in the world is the on/off button for this monitor? I'm having issues with the screen coming on whenever the computer is turned on, but I cannot troubleshoot without locating this switch.
Asked by: sc1106
The power joystick is located on the bottom center of the monitor frame. For assistance with your monitor, please give our computer specialists a call at 800-243-0000.
Answered by: ChrisPSM
Date published: 2019-11-13
Is the height of the screen adjustable?
Asked by: lauram121
No, the height of the monitor cannot be adjusted.
Answered by: ChrisPSM
Date published: 2019-10-23
Does the LG 24MK400H-B 24" Class Full HD Monitor have built-in speaker?
Asked by: Rehne
Hello, the 24MK400H-B does not have built-in speakers. ^AC
Answered by: Amber C
Date published: 2018-12-12
Which LG monitors are compatible with a Mac (Mac Mini) computer?
Asked by: ABQGreg
Most, if not all of our monitors are Plug and Play monitors so they all will work with a Mac Mini. It's just a matter of connectivity and depending on what connections you have on your mac mini, you may or may not need adapters to make the necessary connections depending on what connectivity the monitor has...^IFV
Answered by: LGJoel
Date published: 2018-12-10
Can this monitor be use as a computer monitor and cable TV?
Asked by: Dking174
The main difference between a monitor and a TV is that monitors do not have built-in tuners like TVs do and only a few monitors have built-in speakers. To use the LG 27" Class Full HD TN Monitor with AMD FreeSync (27" Diagonal), Model # 27MK400H to watch cable programming, your cable's Set-Top box will need to have an HDMI Out which you can connect to the HDMI In on the monitor and you will need to connect a pair of active or passive computer speakers to the monitor for sound since it doesn't have built-in speakers...^IFV
Answered by: LGJoel
Date published: 2018-10-17
I have two camera systems, so can i input both a HDMI and dsub at the same time to this monitor? Can i split screen the two systems on the one monitor display at the same time?
Asked by: justin113
The HDMI port on the LG 27" Class Full HD TN Monitor with AMD FreeSync (27" Diagonal), Model # 27MK400H is a digital port while the D-Sub port on it is an analog port so the two ports are independent on one another. You cannot view two inputs simultaneously on this monitor, it does not support Picture-by-Picture. You can download the OnScreen software which has Screen Split 2.0 that enables you to resize and display multiple windows at once, with 14 options including four different picture-in-picture (PIP) choices...^IFV
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Browse all of LG’s innovative, state-of-the-art computer monitors, including:
5K monitors. Take it up a notch with the LG UltraFine monitor, boasting an immersive 27-inch display with 5120 x 2880 resolution and 218 ppi that lets you experience the beauty of a MacBook or MacBook Pro on a large 5K screen. Add to that an unbelievable color spectrum of P3 99% and you’ll be editing and enjoying high-res photos like never before. Too much for you to handle? There’s an impressive 21.5-inch Mac-friendly 4K version as well.
21:9 Curved UltraWide monitors. These high-performance, feature-packed monitors are quite the multitaskers themselves, featuring UltraWide 21:9 resolution, 4-Screen Split, Mac-compatibility, Dual Linkup and stunning Full HD 1080p. They’re the perfect solutions for designers, photographers, gamers and other professionals who need more room for their big ideas.
IPS monitors. Boasting true-to-life colors, IPS computer monitors lessen color loss and help keep colors consistent at virtually any angle. The LED backlighting delivers deep black levels and rich colors for an amazing contrast and color detail.
Gaming monitors. Get panoramic multitasking and immersive gaming with features like a 144Hz refresh rate—the highest of any gaming monitor—plus a response time of less than 1ms (1/1000 of a second) in Motion 240 Mode. It’s the ideal monitor for real-time strategy and first-person shooters. Dynamic Action Sync lets you catch every single moment in real time, while LG’s Black Stabilizer brightens dark scenes so the enemy can’t hide. Get true-to-life color and brilliant clarity from virtually every angle.
TV monitors. Get Full HD 1080p entertainment from the TV, as well as your computer. With features like a built-in digital tuner and Dolby Surround sound, LG TV monitors can bring your favorite movies and TV shows to life, along with your favorite online content and games.
Discover the latest innovations in performance and technology with LG computer monitors—and choose one that fits your world. From 4K, IPS and gaming monitors, to TV, LED, UltraWide, UltraFine options and more. It’s time to make life good.