27” LG UltraGear™ OLED Gaming Monitor, Dual Mode (720Hz@HD, 540Hz@QHD), DP2.1, Black

27GX790B-B

front view of the monitor with the stand down

+15 degree side view of a tilted monitor

Key Features

27-inch QHD (2560x1440) OLED display
VESA DisplayHDR™ True Black 500
OLED with QHD 540Hz - HD 720Hz Dual-Mode
0.02ms (GtG) response time
NVIDIA® G-SYNC® Compatible / VESA Certified AdaptiveSync / AMD FreeSync™ Premium Pro
Ergonomic design with tilt, swivel, pivot, adjustable height and mountable wall

Digital Trends 2025

Readers' Choice best monitor lineup for gamers and those demanding high-quality performance

Born to game

*Images have been simulated to enhance feature understanding, and may differ from actual use experience.

A composite promotional graphic for LG OLED technology featuring five sections: ‘LG’s Brightest OLED’ with an RGB beam graphic, ‘Perfect Visual Experience’ with an astronaut character and certification icons, a split gaming scene labeled ‘QHD 540Hz – HD 720Hz Dual-Mode,’ a purple-blue gradient panel displaying ‘VESA DisplayHDR True Black 500,’ and a colourful particle burst with the text ‘DCI-P3 99.5%

The word 'DISPLAY' in large gradient letters centreed on a dark background with a thin outlined box extending from the left.

LG's Brightest* 4th Gen OLED

Introducing LG’s gaming monitor powered by 4th Gen OLED with revolutionary Primary RGB Tandem technology—reaching up to 1500 nits of peak brightness for visibly clearer gameplay, helping you to see on-screen visuals with clarity even in bright environments. In fast-paced or sunlit in-game scenes, enhanced APL and reduced ABL help maintain consistent luminance without dimming critical visuals. UL Verified Perfect Black, colour and VESA DisplayHDR™ True Black 500, this next-gen OLED delivers the contrast and clarity gamers need to react faster, see more, and stay immersed in every frame.

LG UltraGear 27GX790B monitor placed on a desk overlooking a cityscape at sunset, displaying a fantasy game scene with a cloaked character standing in a snowy mountain environment. Surrounding the monitor are speakers, a keyboard, a clock, small figurines, and a mug

*Images have been simulated to enhance feature understanding, and may differ from actual use experience.

*As of November 2025, among all LG models using WOLED prior to 4th Gen. OLED, 27GX790B offers the highest brightness.

Next-Gen OLED Brilliance

Powered by 4th Gen Primary RGB Tandem OLED, the 27GX790B delivers brighter visuals with less power than the previous 3rd Gen OLEDs—reaching up to 1500 nits of peak brightness. Its advanced 4-stack RGB structure produces deeper contrast, sharper detail, and stunning colour precision. Experience clearer shadows, deep immersion, and visual consistency in every frame—built for serious gaming.

*Images have been simulated to enhance feature understanding, and may differ from actual use experience.

UL-verified Perfect visual experience, consistent in both low and bright light

Perfect black

Perfect Black is UL-verified and delivers true black levels to enhance perceived brightness and contrast, whether it's bright or dark around you.

Perfect colour & 100% colour fidelity

Perfect colour and 100% colour Fidelity deliver accurate colour expression even under varying lighting conditions, from low light to bright ambient environments.

Perfect reproduction

UL-verified Perfect Reproduction delivers that actual game content is faithfully rendered on screen, maintaining intended colour and detail in both dark and bright environments. Unlike static image-based metrics, this certification reflects real-world content reproduction accuracy.

Side-by-side comparison of non-WOLED and 4th Gen. WOLED display quality, showing enhanced brightness, colour, and clarity on the right side using 4th Gen. WOLED technology. The monitor sits on a desk with a game controller, keyboard, and headset.

*Images have been simulated to enhance feature understanding, and may differ from actual use experience.

Deeper Detail with VESA DisplayHDR™ True Black 500

Experience unparalleled depth and vibrant realism with VESA DisplayHDR™ True Black 500, delivering detailed black expression even in the darkest scenes. With DCI-P3 99.5% (Typ.) colour gamut, the monitor provides that colours are displayed with realistic detail, as close to the original intent as possible.

*Images have been simulated to enhance feature understanding, and may differ from actual use experience.

UL-verified advanced eye comfort technologies

Featuring AGLR(Anti-glare and low reflection), LG WOLED’s UL-verified advanced eye comfort technologies minimise frustrating reflections and keep your eyes comfortable, delivering crystal-clear gaming performance with consistent clarity. With UL verifications in key areas—limiting harmful blue light exposure and preventing distractions from flickering lights—these technologies promote visual comfort and contribute to a smoother gaming experience, whether you’re gaming in bright environments or LED-lit rooms.

LG UltraGear 27GX790B monitor on a desk setup displaying a side-by-side comparison labeled ‘non-applied’ and ‘applied,’ showing different visual states of a sci-fi armored character. The desk includes speakers, a keyboard, figurines, a controller, a PC tower, and headphones. Along the bottom are multiple UL certification badges for flicker-free, discomfort glare-free, low blue light, and Eyesafe credentials

*All pictures shown are simulated for illustration purpose only.

*LG WOLED have been verified as Flicker-Free, Discomfort Glare Free, and Low Blue Light by UL.

*Certificate Number: Flicker-Free Display (OLED) - A196009, Discomfort Glare Free - V563481 (conditions of UGR less than 22), Low Blue Light Hardware Solution Platinum - V745051, Eyesafe 3.0 CPF60 - V745354, Eyesafe 3.0 RPF40 - V275741

*The above feature may vary depending on the user’s computing environment or conditions.

The word 'SPEED' in large gradient letters centreed on a dark background with a thin outlined box extending from the left.

720Hz(@HD) – 540Hz(@QHD) Dual-Mode with selectable options

With VESA Certified Dual-Mode, enjoy UltraGear’s fastest performance with up to 720Hz—the highest refresh rate ever introduced. Seamlessly switch between QHD 540Hz for detailed visuals and HD 720Hz for ultra-fast action. Choose your preferred refresh rate and screen size via On-Screen Display, or toggle instantly through LG Switch for optimised gameplay across every genre.

Graphic comparing two gaming scenes: a fantasy warrior rendered in QHD at 540Hz on the left, and a rally race car rendered in HD at 720Hz on the right. The two scenes overlap slightly against a dynamic abstract blue and red background, with ‘540Hz QHD’ and ‘720Hz HD’ labels displayed beside each image

High-speed bandwidth by DisplayPort 2.1

The latest DisplayPort 2.1 on the 27GX790B delivers next-generation bandwidth optimised for ultra-high-speed gaming, supporting stable performance even at extreme refresh rates. Extending this connectivity, the USB-C port supports streamlined single-cable display output and data transfer—ideal for modern setups that require flexibility without extra clutter. Completing the configuration, dual HDMI 2.1 ports can provide smooth compatibility with the latest consoles and gaming PCs, creating a fully integrated high-performance environment across devices.

*Images have been simulated to enhance feature understanding, and may differ from actual use experience.

*DP, HDMI cables are included in the package.

*The graphics card is NOT included in the package.

Overwhelming speed, diving into gaming

The ultra-fast 0.02 response time (GtG), reducing reverse ghosting and providing fast response time, lets you to enjoy a whole new gaming performance

*Images have been simulated to enhance feature understanding, and may differ from actual use experience.

*Select 'Faster Mode' to perform '0.02ms Reponse Time'. (Game Adjust → Response Time → Faster Mode).

The word 'TECHNOLOGY' in large gradient letters centreed on a dark background with a thin outlined box extending from the left.

Certified with a widely adopted technology

Powered by AMD FreeSync™ Premium Pro, NVIDIA-validated G-SYNC® compatibility, and VESA AdaptiveSync™ certification, this monitor provides tear-free, ultra-smooth visuals and low latency, delivering unmatched gaming precision and fluidity.

Comparison of fluid gaming image - The left image is tearing, and the Right image is tear-free.

*Images have been simulated to enhance feature understanding, and may differ from actual use experience.

*The performance of the feature is compared to the models not applying the sync technology.

*Errors or delays may occur depending on the network connection.

ClearMR 21000 for sharper, cleaner motion

VESA certified by ClearMR 21000, this monitor finally captures even the subtle blurring that occurs around the edges of moving objects, displaying fast-moving action with sharpness and detail. Also, it allows you to take a step closer to victory.

*Images have been simulated to enhance feature understanding, and may differ from actual use experience.

Side-by-side gaming scene comparing feature off and on, showing a blurred moving character on the left with ‘OFF,’ and a sharper, more stable image on the right with ‘ON.’ A circular zoom overlay highlights the visual difference

Dynamic Action Sync

Reducing input lag with Dynamic Action Sync, gamers can catch critical moments in real-time and respond quickly.

Dark interior scene displayed twice, with the left image labeled ‘OFF’ showing darker shadow areas, and the right image labeled ‘ON’ showing brighter, more visible details within the shadows

Black Stabiliser

Black Stabiliser enhances visibility in dark scenes, revealing hidden details and improving clarity for smoother navigation through shadowy environments or sudden light changes.

Crosshair

The target point is fixed in the centre to enhance shooting accuracy.

*Images have been simulated to enhance feature understanding, and may differ from actual use experience.

Smarter control, seamless switching by LG Switch

With the LG Switch app, it's easy to optimise your monitor for both gaming and everyday use. Effortlessly manage your monitor settings—adjust image quality and brightness to your preference, then apply your settings instantly using a hotkey. The app also lets you split the screen into 11 layouts and launch your video call platform in a click—bringing even more convenience to your setup.

Short feature video demonstrating LG UltraGear’s LG Switch function, showcasing seamless input source switching and enhanced user control for an optimised gaming experience in the 2025 UltraGear monitor lineup.

*This video is for illustrative purposes only and may not reflect the actual 27GX790B product specifications.

*LG Switch requires software *This video is for illustrative purposes only and may not reflect the actual 27GX790B product specifications.

*LG Switch requires software and manual download from LG.com for proper use.and manual download from LG.com for proper use.

The 4-pole headphone cord is connected to the monitor.

Plugin for immersive
sound effect

Enjoy your games while having voice chat by connecting easily with 4-pole headphone out. Also, you can feel even more immersive with virtual 3D sound with DTS Headphone:X.

*Headsets sold separately.

Compact and sleek

Experience our virtually borderless design featuring a fully adjustable base with swivel, tilt, and height. A clutter-free slim stand and wide-range swivel adjustment are designed to minimise desk space usage and eliminate dead space efficiently, while adding a sleeker, more refined look to your setup.