Our Verdict
Unfortunately, the LG UF6400 isn't a great TV. Movie lovers will find that the picture lacks some punch and gamers won't be satisfied with the responsiveness. Even if the TV is compatible with most PC inputs, the lag and somewhat-blurry 4k resolution will still make it a no-go. The only scenario where this TV could be viable is in an average-lit room with off-axis seating. For most people's needs, there is a better TV than this one.
- Good viewing angle
- WebOS is a nice smart platform
- Uses the less accurate RGBW 4k pixel structure
- Poor picture quality in the dark
- Does not excel at anything
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We buy and test dozens of TVs yearly, taking an objective, data-driven approach to deliver results you can trust. Our testing process is complex, with hundreds of individual tests that take over a week to complete. Most of our tests are done with specially designed test patterns that mimic real content, but we also use the same sources you have at home to ensure our results match the real-world experience. We use two main tools for our testing: a Colorimetry Research CR-100 colorimeter and a CR-250 spectroradiometer.
Test Results
This isn't the worst TV we have seen for blacks, but it is still near the bottom of the list. Blacks will look gray when you watch this TV in the dark.
This is always the strong point of IPS TVs. The colors of the UF6400 don't lose much saturation when viewed from the side. This TV is suitable for a wide family room.
Update 01/06/2017: We have changed the methodology of testing. Since this is an old TV which we don't have anymore, we extrapolated the results from 2016 TVs.
For 24p sources like Blu-ray, the TV is able to remove judder correctly. Unfortunately, movies over cable or from some streaming services will still have judder inconsistently. Since this is a 60 hz TV and it has TruMotion, it can only interpolate signals under 60 hz.
Under game mode, the TV is responsive enough for casual gaming, but any hardcore players will feel a bit of lag on their controller inputs. Compared to other 2015 TVs, the input lag is average-high.
Most of the modes tested work on this TV except for 1080p@120Hz. To achieve 4k @ 60Hz turn on 'HDMI Ultra HD Deep Color'. To add chroma 4:4:4, enable 'HDMI-PC' under the picture menu. Unfortunately, if you use the TV as a PC monitor, the input lag (same as in game mode) will be quite apparent. Even more so for games like first person shooters, which require fast reflexes.
WebOS is a great smart TV platform and has a good amount of available apps. Unfortunately, you don't get the smart remote with this TV, so it isn't the best way to experience the platform. It takes more time to input text, but other than that, the navigation is straightforward. You can read our overview of LG's WebOS here.





























