LG UJ6300 TV Review

Tested using Methodology v1.2
Updated Jun 02, 2017 at 11:55 am
LG UJ6300 Picture
Mixed Usage
Value for price beaten by
: Not at the latest test bench
TV Shows
Video Games
HDR Movies
HDR Gaming
PC Monitor
This TV was replaced by the LG UK6300
Type LED
Resolution "4k"

The LG UJ6300 UHD RGBW LED TV is an ordinary TV with a wider than average viewing angle. It features the best smart platform available and impressively low input lag. The out of the ordinary "RGBW" pixel structure also can cause smaller details and straight lines to lose sharpness.

Our Verdict

7.0 Mixed Usage

The UJ6300 is an average TV for a mixed usage. It has passable picture quality and a decent viewing angle, but it doesn't get very bright in SDR. Input lag is amongst the lowest though.

  • Very low input lag
  • Low motion blur
  • Not very bright
  • Blacks aren't uniform
  • Uses less accurate RGBW pixel structure
5.9 Movies

Subpar choice for movies in a dark room. The UJ6300's blacks are not very deep and lack uniformity, causing black letterboxes and darker scenes to often look blotchy. It also lacks a local dimming feature to help control these issues.

7.4 TV Shows

The UJ6300's TV shows performance leaves much to be desired. It isn't bright enough to be used in a bright setting, and the screen finish's handling of reflection isn't great either.

7.2 Sports

Decent TV for sports watching. Since picture quality is retained better than average from the side, it makes the UJ6300 quite suitable for game viewing parties with a lot of guests. The uniformity of grays and colors is also decently good. Unfortunately, it doesn't get very bright, which might be an issue for afternoon games in a bright living room.

7.9 Video Games

The UJ6300 provides a satisfactory experience with video games. It has low motion blur, which makes fast motion crisp and clear, and its input lag is some of the lowest available, so it feels very responsive.

5.7 HDR Movies

Passable HDR performance. The UJ6300's brightness is a bit better in HDR than SDR, but it still isn't great. The lack of local dimming and wide color gamut limits its abilities further.

7.2 HDR Gaming

Good HDR gaming performance. While the HDR effect isn't very strong, the input lag and overall gaming experience remain good even in HDR.

7.7 PC Monitor

Decent PC monitor. The UJ6300 has very low input lag and motion blur, so desktop use is responsive and isn't distracting. The viewing angle is also wide enough for use from up close. However, it cannot get very bright and its RGBW pixel structure can cause fine items on-screen to not look very sharp.

  • 7.0 Mixed Usage
  • 5.9 Movies
  • 7.4 TV Shows
  • 7.2 Sports
  • 7.9 Video Games
  • 5.7 HDR Movies
  • 7.2 HDR Gaming
  • 7.7 PC Monitor
  1. Update 5/8/2018: 1440p @ 60Hz is not a supported input. It was mistakenly tested as supported, but has now been retested and found to be not supported. It is unlikely a firmware update caused this change. The score has been updated.
  2. Update 3/12/2018: Converted to Test Bench 1.2.
  3. Update 9/4/2017: 4:4:4 color is now properly shown in HDR content when in PC mode, as of webOS update 3.6.
  4. Update 8/31/2017: Retested color gamut and color volume before the start of the 20/7 OLED burn-in test, on software version '3.60.03'. Both are worse than originally tested. Scores and images have been updated.
  5. Update 8/10/2017: Converted to Test Bench 1.1.

Test Results

Curved No

The design of the UJ6300 is very basic, and everything is made of plastic. There are no stylistic elements like the higher end UJ7700, and the TV doesn't look bad but it certainly won't be the centerpiece of any room. Some of the rear-facing inputs may be difficult to access if placed close to a wall.


The stand is almost as wide as the TV and looks similar to the UH6100 from 2016. It is made of plastic but supports the TV quite well.

Footprint of the 49" TV stand: 7.5" x 33.5"

Wall Mount VESA 200x200

The rear of the TV is simple, and a similar design but slightly less reflective than the UJ7700. Some of the inputs which face out the back of the TV may be difficult to access if the TV is placed close to a wall or VESA mounted.

Borders 0.79" (2.0 cm)

The borders of the TV are slightly thicker than average, but due to their tapered edge, they don't appear too thick. They are made of plastic.

Max Thickness 3.23" (8.2 cm)

The TV is quite thick, with the thickest part near the base of the TV below the inputs. It will stick out from the wall a bit if mounted.

Maximum Temperature
95 °F (35 °C)
Average Temperature
91 °F (33 °C)

The TV is fairly cool, only getting slightly warm along the top edge and a few places on the back. As with most TVs, there are vents on the bottom edge and a vent on the back of the TV, near the top.

Build Quality

The build quality of the UJ6300 is decent. Everything is made of plastic, but these parts certainly won't break under normal use.

Picture Quality
Picture Quality
Native Contrast
1314 : 1
Contrast with local dimming

The LG UJ6300 has a passable contrast ratio for a LED TV. This low contrast ratio makes dark scenes appear washed-out and makes blacks appear more gray than really black, especially when set in a dark room. The TV fares much better when set in a bright room since the light usually makes the low contrast ratio less noticeable.

If you compare this IPS TV with other IPS TVs we have reviewed before, the UJ6300 contrast ratio of 1314:1 is actually better than most of them.

Picture Quality
Local Dimming
Local Dimming

The UJ6300 does not have a local dimming feature. The video is for reference only.

Picture Quality
SDR Peak Brightness
SDR Real Scene Peak Brightness
174 cd/m²
SDR Peak 2% Window
167 cd/m²
SDR Peak 10% Window
168 cd/m²
SDR Peak 25% Window
169 cd/m²
SDR Peak 50% Window
171 cd/m²
SDR Peak 100% Window
175 cd/m²
SDR Sustained 2% Window
167 cd/m²
SDR Sustained 10% Window
167 cd/m²
SDR Sustained 25% Window
168 cd/m²
SDR Sustained 50% Window
170 cd/m²
SDR Sustained 100% Window
174 cd/m²

Disappointing SDR peak brightness in the 'Expert (Dark Room)' picture mode. While this mode has the most accurate picture quality, it is much dimmer than the 'Standard' picture mode, as shown in this brightness plot. If you find the TV not bright enough, it's best to use the 'Standard' mode with a color temperature of 'W30' and as many of our recommended settings as applicable.

With 'Expert (Dark Room)' the TV is only bright enough for a really dark room, while with 'Standard' it is bright enough for a moderately lit room.

Picture Quality
HDR Peak Brightness
HDR Real Scene Peak Brightness
297 cd/m²
HDR Peak 2% Window
319 cd/m²
HDR Peak 10% Window
319 cd/m²
HDR Peak 25% Window
318 cd/m²
HDR Peak 50% Window
318 cd/m²
HDR Peak 100% Window
318 cd/m²
HDR Sustained 2% Window
317 cd/m²
HDR Sustained 10% Window
318 cd/m²
HDR Sustained 25% Window
317 cd/m²
HDR Sustained 50% Window
317 cd/m²
HDR Sustained 100% Window
317 cd/m²

Mediocre HDR peak brightness. The brightness doesn't change depending on the content shown, as all our tests were about equal (the real scene test is measured at the edge of the screen which is dimmer). This constant brightness is a good thing, but it's still not nearly as bright as intended for HDR content. A plot of brightness over time is shown here.

If you find HDR content too dim in the 'Cinema' and 'Game' picture modes, you can enable 'Dynamic Contrast', as explained here. This won't increase the brightness of highlights but it will make most of the scene brighter, at the cost of slightly worse picture quality. The 'Standard' picture mode is even brighter, but also has worse picture quality than 'Movie'. This can be alleviated somewhat by using our recommended settings with a 'W30' color temperature.

Picture Quality
Gray Uniformity
50% Std. Dev.
5.567 %
50% DSE
0.210 %
5% Std. Dev.
0.657 %
5% DSE
0.069 %

The gray uniformity of the UJ6300 could be better. The 50% standard deviation is pretty high, and this is caused mostly because of the darker edges corners, as you can see on the 50% gray uniformity test picture. Some vertical bands are slightly visible near the center, but dirty screen effect is not that much noticeable when watching content like sport, which is better than what we had on the UJ7700.

Looking at the 5% gray uniformity picture and numbers, not much stand out and these are very good results.

Picture Quality
Viewing Angle
Color Shift
22 °
29 °
Black Level
75 °

Mediocre viewing angle, better than almost all VA TVs but not as good as some other IPS TVs such as the UH6150. Blacks remain essentially unchanged no matter the angle, but colors shift and brightness decreases at moderate angles.

Picture Quality
Black Uniformity
Native Std. Dev.
3.168 %
Std. Dev. w/ L.D.

The UJ6300 black uniformity is poor. Most of the uniformity issues are due to the darker edges and corners, similarly to what affected the gray uniformity. Only the right upper corner is a bit brighter than the rest of the screen. Some vertical lines are also visible toward the right side of the screen.

Picture Quality
Screen Finish
Total Reflections
3.3 %
Indirect Reflections
0.7 %

The UJ6300 is quite good at handling reflections. The screen is semi-gloss which helps to reduce the intensity of direct reflections but does diffuse them across the screen. For a room with a couple of windows, this is not an issue, but bright glare on the screen may be a problem.

Picture Quality
Pre Calibration
Picture Mode
Expert (Dark Room)
White Balance dE
Color dE
Color Temperature
5763 K

Out of the box, the UJ6300 accuracy could be better. The white balance dE and the color dE are high enough that almost anybody could notice it, even if not an enthusiast. The white balance is on the warm side, missing mostly blue. Looking at the color accuracy, all the color are a bit off, with the blues and cyans being the one with the higher dE. Overall, the gamma curve is not very flat, but the gamma number is not that far from our 2.2 target.

Picture Quality
Post Calibration
Picture Mode
Expert (Dark Room)
White Balance dE
Color dE
Color Temperature
6550 K

The calibration process of the UJ6300 was a bit longer than usual, but this is mostly because the setting menu was affecting the measurements. This happens from time to time depending on the TV models, but in that particular case, we had to go out of the menu every time before taking some reading. Besides that, the process worked pretty well, and the high white balance dE what corrected and brought down to a negligible 0.24, which is an excellent result. As the consequence of the correction of the white balance, the gamma was flattened to track more closely our 2.2 target.

When it comes to the color accuracy, the provided color management system has proven to be quite good, even though some colors, mostly in the blue and red, were still a bit off. But even with this small error, the total color dE is now more than half what is was before calibration.

You can see our recommended settings here.

Picture Quality
480p Input

Upscaling of low-quality content such as DVDs is good. Like most LG TVs, some halo artifacts are visible along edges but this isn't much of an issue.

Picture Quality
720p Input

720p content such as cable looks good. Details are preserved and the image isn't too soft.

Picture Quality
1080p Input

1080p sources such as Blu-rays look good. The image remains clear and detailed.

Picture Quality
4k Input

With some 4k content (such as text for PC monitor use) the less accurate RGBW pixel structure results in some artifacts. This is the same as the UH6500 and visible in the chroma test pattern of that TV here. This is also visible in the pixels photo.

Picture Quality
Color Gamut
Wide Color Gamut
DCI P3 xy
76.21 %
DCI P3 uv
82.09 %
Rec 2020 xy
54.71 %
Rec 2020 uv
59.88 %

Standard color gamut, only good enough for SDR Rec. 709 content. When watching HDR content, greens will be significantly undersaturated, and blues and reds too to a lesser extent. Luckily the TV is fairly accurate at showing the colors it is able to, especially P3 colors.

In the 'Cinema' and 'Game' picture modes the TV dims HDR content significantly, as shown by their EOTFs here and here. This isn't present in 'Standard', shown here, and is alleviated in 'Cinema' and 'Game' by enabling 'Dynamic Contrast', as shown here and here.

Update 08/31/2017: Retested color gamut before the start of the 20/7 OLED burn-in test, on software version '3.60.03'. The color gamut is worse than originally tested, because the TV is using other subpixels even when showing pure colors. Shown here is the TV's pixels when showing pure blue, and the green subpixel is also lit, which reduces the saturation of the blue. The color gamut scores and images have been updated.

Picture Quality
Color Volume
Normalized DCI P3 Coverage ITP
55.6 %
10,000 cd/m² DCI P3 Coverage ITP
19.0 %
Normalized Rec 2020 Coverage ITP
39.3 %
10,000 cd/m² Rec 2020 Coverage ITP
13.3 %

Poor color volume. The TV's RGBW pixel structure prevents it from making bright colors nearly as bright as it can make white. Its color gamut narrows severely when showing dark colors, and its black level is not good.

Update 08/31/2017: Retested color volume before the start of the 20/7 OLED burn-in test, on software version '3.60.03'. The color gamut is worse than originally tested, because the TV is using other subpixels even when showing pure colors. Shown here is the TV's pixels when showing pure blue, and the green subpixel is also lit, which reduces the saturation of the blue. The TV's color volume is reduced because the color gamut is reduced. The color volume scores and images have been updated.

Picture Quality
Color Depth
10 Bit
Red (Std. Dev.)
0.101 dE
Green (Std. Dev.)
0.116 dE
Blue (Std. Dev.)
0.093 dE
Gray (Std. Dev.)
0.115 dE

The UJ6300 can display our test gradient image pretty well and without any banding problems. Some little imperfections can be seen in the dark blue and green, but those are very minor does not affect regular content.

Picture Quality
Temporary Image Retention
IR after 0 min recovery
7.85 %
IR after 2 min recovery
0.34 %
IR after 4 min recovery
0.00 %
IR after 6 min recovery
0.00 %
IR after 8 min recovery
0.00 %
IR after 10 min recovery
0.00 %

The UJ6300 suffers from image retention and it is fairly easy to notice it, as is does not take a long exposure to a still image to create some retention. As you can see on our test picture, taken right after the 10 minutes burn-in scene, the image retention is very clear and easy to see. It was also easy to notice during the review process, as we had to give it some time, running normal video content to clear up the retention, before tests like the gray uniformity, since just displaying, let's say our contrast checkerboard, did induce image retention.

On the good side, the retention does not last very long, even if it is pretty strong at the beginning. As you can see from the test results, after 4 minutes of recovery time, the image retention was completely gone and the screen was back to normal.

Picture Quality
Permanent Burn-In Risk
Permanent Burn-In Risk

Although some IPS panels can suffer from temporary image retention, this doesn't appear to be permanent as seen in our long-term test.

Picture Quality

The less accurate RGBW pixel structure causes some artifacts when viewing some 4k content (such as PC text) from up close.

Response Time
80% Response Time
7.1 ms
100% Response Time
16.7 ms

The response time is good, so only a short trail can be seen following fast-moving objects. This is similar to the UJ7700.

PWM Dimming Frequency
120 Hz

The TV uses PWM at 120Hz to dim the backlight, starting at 100/100 backlight setting. Lowering the setting shortens the duty cycle, while amplitude remains nearly constant. Backlight PWM helps clear up motion slightly, but results in duplications following fast-moving objects, visible in the motion blur box. The backlight oscilloscope was taken in HDR mode, as the TV doesn't utilize its full brightness in SDR. 100% backlight in SDR looks like this.

Black Frame Insertion (BFI)
Optional BFI
Min Flicker for 60 fps
120 Hz
60 Hz for 60 fps
120 Hz for 120 fps
Min Flicker for 60 fps in Game Mode
120 Hz

Like with other 2017 LG TVs, there is no option to reduce the flicker frequency to 60 Hz, although the TV's 120 Hz PWM flicker does help somewhat to make motion look more clear during fast-paced content.

Motion Interpolation
Motion Interpolation (30 fps)
Motion Interpolation (60 fps)

The UJ6300 has a 60Hz panel and can interpolate lower frame rate content by setting 'TruMotion' to 'User' and increasing the 'De-Judder' slider. However, the UJ6300 can't produce as strong of a soap opera effect as 120Hz TVs such as the UH7700 from 2016, and cannot interpolate 60Hz content. Note that any motion interpolation will introduce artifacts, so use a small value unless you really like the soap opera effect. There are also some bugs in the interpolation which causes more stuttering than usual, especially with our full-screen pattern.

Frame Hold Time @ 24 fps
25.0 ms
Frame Hold Time @ 60 fps
0.0 ms

The LG UJ6300 is great at displaying content without stutter, even at low frame rates such as 24p movies. The response time causes some blur to appear between frames, which helps to smooth the transition.

24p Judder
Judder-Free 24p
Judder-Free 24p via 60p
Judder-Free 24p via 60i
Judder-Free 24p via Native Apps

Only 24p movies playing from 24p sources like DVD and Blu-rays players are judder free. The UJ6300 can't remove judder from 24p movies playing from 60p/60i sources like cable and satellite boxes.

To be able to display 24p movies without judder when playing from 24 sources, the 'Real Cinema setting must be turned on.

Variable Refresh Rate
Native Refresh Rate
60 Hz
Variable Refresh Rate
4k VRR Maximum
4k VRR Minimum
1080p VRR Maximum
1080p VRR Minimum
VRR Supported Connectors

THe LG UJ6300 doesn't support any variable refresh rate features, and has a native 60Hz panel.

Input Lag
1080p @ 60Hz
13.1 ms
1080p @ 60Hz + HDR
12.7 ms
1080p @ 60Hz Outside Game Mode
45.9 ms
1080p @ 120Hz
4k @ 60Hz
13.0 ms
4k @ 60Hz + HDR
12.8 ms
4k @ 60Hz @ 4:4:4
12.6 ms
4k @ 60Hz @ 4:4:4 + 8 bit HDR
12.6 ms
4k @ 60Hz Outside Game Mode
62.6 ms
4k With Interpolation
95.9 ms
4k @ 120 Hz
4k with Variable Refresh Rate
1080p with Variable Refresh Rate

Outstanding low input lag. When in the Game picture mode or in any picture mode, when the input's icon is set to PC, the TV's input lag is an excellent ~11 ms, which should please almost any gamer. However, only the Game picture mode has low input lag for HDR content, as when HDR content is played, when the input's icon is set to PC, the TV acts as though the icon is not PC.

Update 9/4/2017: HDR is now supported in PC mode as of WebOS update 3.6. 4:4:4 color is now properly displayed in HDR content when in PC mode. All input lag values have been retested with the newer firmware, and remain nearly unchanged.

Supported Resolutions
1080p @ 60Hz @ 4:4:4
1080p @ 120Hz
1440p @ 60Hz
4k @ 30Hz @ 4:4:4
4k @ 60Hz
4k @ 60Hz @ 4:4:4
4k @ 120Hz

Most of the common input resolutions are supported. 4:4:4 color is only properly displayed when the input's icon is set to PC. 4k @ 60 Hz @ 4:2:2 or 4:4:4 color can only be played when 'HDMI ULTRA HD Deep Color' is enabled for the input being used. 4:4:4 color is not properly displayed for HDR content, because when HDR content is played when the input's icon is PC the TV acts as though the input's icon wasn't PC.

Update 9/4/2017: HDR is now supported in PC mode as of WebOS update 3.6. 4:4:4 color is now properly displayed in HDR content when in PC mode.

Although 4:4:4 color is displayed properly, the screen's RGBW pixel structure produces artifacts when showing fine color detail, artifacts like jagged lines and missing pixels. This is shown here on our 4:4:4 test image when displayed on the RGBW UH6500. The same image displayed on an RGB TV like the Sony X750D has no such artifacts, as shown here. These artifacts aren't a huge problem but they are noticeable at times when using the TV as a PC monitor.

Update 05/08/2018: 1440p @ 60Hz is not a supported input. It was mistakenly tested as supported, but has now been retested and found to be not supported. It is unlikely a firmware update caused this change. The score has been updated.

Side Inputs
Rear Inputs
Total Inputs
Digital Optical Audio Out 1
Analog Audio Out 3.5mm 0
Analog Audio Out RCA 0
Component In 1 (shared)
Composite In 1 (shared)
Tuner (Cable/Ant) 1
Ethernet 1
DisplayPort 0
IR In 0