TCL S405 55" (55S405) vs TCL S517 49" (49S517)

The S405 is a decent, affordable pick if you're a casual viewer. You'll get decent picture quality and a good 4K experience, but the HDR performance might be lacklustre due to the lack of local dimming, wide color gamut, and low HDR peak brightness.

The S405 is versatile enough to be used as a general-purpose display.

The picture quality is decent for movies and TV shows, and it checks all the boxes that makes a TV suitable for gaming, sports, and as a computer monitor: low input lag, low motion blur, good screen uniformity, and full 4:4:4 color support.

Even when the S405 is mounted on a wall, you'll still have access to all essential inputs and outputs which are situated on the side of the unit.

The S405 looks decent with adequately deep black levels, above-average color accuracy, and sufficient peak brightness levels for most content.

It’s especially great at reproducing dark scenes thanks to the panel’s contrast ratio of about 4000:1, which means blacks can get really dark at about 4000 times darker than the brightest white it can produce.

Colors are spot-on even without calibration, and the panel can get bright enough with a peak brightness level of ~200 nits to make them pop in dark environments.

The best viewing experience will be in a dark environment where the panel won’t have to compete with light. The S405’s screen can’t really get bright enough to perform as well in bright environments.

The S405 is excellent at reproducing colors accurately out of the box.

Even without calibration, the colors are spot-on - they're very close to what the source signal demands, and any inaccuracies are generally considered imperceptible to most end users.

The overall average difference between the source signal and the panel's reproduction of the color is measured in Delta-E, where lower means better accuracy. The S405 has a Delta-E of below 2.0, and anything below 3.0 is generally considered accurate for most end users.

Color calibration can be performed easily via the Roku mobile app. You won't have to fiddle with the remote trying to set the values correctly.

The S405 has no ads on its main interface, although there can be ads in third-party applications. Third-party ads can't be blocked, but the tracking and personalisation can be limited through the TV's settings.

The S405 is excellent for gaming - the overall experience will be very responsive and fluid, thanks to the really low input lag and barely noticeable motion blur.

It has an input lag of ~15ms that makes the TV highly responsive to user input - gamers will have no issues keeping their actions in sync with what's on the display. The panel can fully change its pixels color in under 15ms, resulting in fast-moving objects not leaving any trails on the screen, eliminating virtually all motion blur.

It's also suitable for HDR gaming because there is no increased input lag for HDR, and it has full 4K suport @ 60 FPS, which makes it suitable for all new 4K games.

The S405 runs on the Roku TV smart platform, touted for its simple, straightforward, and lag-free UI.

It’s easy for anyone to grasp how navigation works, thanks to its two-column design with the menu on the left and options on the right.

There’s also no noticeable lag during navigation or menu selection.

The S405 is a good pick for watching sports thanks to its low motion blur and reasonably consistent color uniformity.

Fast-moving objects, like footballs, won't leave any visible trails on the screen due to the low motion blur of ~15ms. While there are slight uniformity inconsistencies in the edges of the panel when displaying large, same-color objects on screen, like football fields, the issues generally go unnoticed by most.

The S405 works well as a computer monitor thanks to its low input lag, barely noticeable motion blur, and full 4:4:4 color support. The 43" model can even be used up close due to its small minimal viewing distance.

The low input lag and low motion blur of ~15ms makes it highly responsive to input and gives it the ability to handle dynamic content well.

It also has full 4:4:4 color support, so text or shapes with hard edges on the screen won't be blurry.

The S405 strikes a nice balance between picture quality, screen size, and input lag, all for an affordable price of below $500. It's a great choice for watching and gaming casually without breaking the bank.

Compared to its direct competitors, it offers decent picture quality that is a tad below them, bigger screen size, and lower input lag.

Content looks decent enough for most casual viewers - the black levels are sufficiently deep, colors are vivid, and it gets bright enough for most types of content in a dark room.

The size difference is pretty huge as options with similar size of 49", or even smaller, cost fairly more than the S405.

Its low input lag of ~15ms contributes to a more responsive gaming experience. It's barely noticeable, and it’s also one of the lowest among 4K TVs, which is an impressive feat in this price bracket.

The TCL S517 is a decent option for pretty much everything, be it gaming, movies, sports, or HDR content. It has noteworthy picture quality, good all-around responsiveness, decent smart features, nice motion handling, and, most importantly, a great price.

The mobile remote app for both iOS or Android can fully and comfortably substitute the real remote – launch apps, input text in apps, control most TV settings, etc.

Also, colors can easily be adjusted close to perfection thanks to the app’s calibration menu.

The S517 comes with the Roku TV smart platform, which provides a comfortable interface and a big app selection.

The interface is quite basic and easy to overlook. It’s smooth and simple to swap to your favorite apps.

Roku TV offers a vast app store with all the most popular apps – Netflix, YouTube, Hulu Plus, Amazon Instant, HBO Go, Vudu and much more. Some apps are even absent from other TV manufacturers Smart TV platforms and unique to Roku.

The S517 is fit for all gamers because it offers a clear, lag-free experience. The TV is very responsive - it has struck a good balance between decent refresh rate, solid input lag, and good response time.

The TV is an ideal choice for console gaming in terms of its native refresh rate. It caps at 60Hz, which is perfect since most games won't benefit from anything higher than this.

The S517 is fast. An action shows on the screen in around 18 milliseconds, which can make the difference between managing to get a frag or waiting for a respawn. The time doesn't substantially increase when gaming in HDR or 4K either - it goes up to roughly 20.5 milliseconds. The only thing to remember is to keep "Game" mode enabled for the lowest possible input lag.

The TCL S517 also handles motion and fast-paced content quite well, it has a good response time. This makes sure you can keep up with fast-moving objects and a lot of action without it all appearing blurry. A full pixel color transition takes only 15.8 milliseconds.

The picture quality when you first open the TV up is quite decent. The only settings that could potentially require tweaking are grey inaccuracy and color inaccuracy. Either way, these are things that most people won't even notice.

The S517 offers a pleasant PC monitor experience not only due to the good responsiveness but also because of the video signal's compression.

The TV won't make text appear blurry while connected to a PC because the signal has no compression and transports color data and luminance fully. This is also known as chroma 4:4:4, and the “Computer” and “Game” modes display it properly at 60Hz.

All of the inputs are conveniently placed on the side of the S517, so you won't have to worry about leaving space between a wall and the TV.

The S517 offers the possibility to represent motion in videos smoother, also known as the "soap opera effect". This is done by making the TV take two frames and try to guess what would a frame in between of those look like, also known as motion interpolation. The frame rate can interpolate up to 60 frames per second.

The S517 does a reasonably good job with upscaling most content to 4K quality, be it 480p DVDs, HDTV or full HD Blu-rays.

The S517 is a much better fit for HDR content and HDR gaming than its competitors due to the wide color gamut, decent color depth, and high contrast.

The TV can display a lot more colors than its similarly-priced counterparts. The coverage of the Digital Cinema P3 color space is very good - 90%.

The color depth is on par with competing options. The S517 has 10-bit color depth, which means that it can display approximately 1.07 billion colors in total. This is important for HDR content because HDR media takes advantage of 10-bit.

The S517 can display deep blacks in the HDR mode because of its high native contrast ratio of 6000:1, which is easily one of the best in the given price range.

The TV can also play all HDR content because it supports both standard formats of HDR - HDR10 and Dolby Vision. They enhance the viewing experience by editing the metadata, that is, the extra information that tells the TV how to display HDR. The formats differ in the way they deal with it, however - Dolby Vision edits the picture on a per scene basis, whereas HDR10 edits everything at the start of the video.

In terms of picture quality, the S517 is comparable to high-end TVs. It displays remarkably deep blacks due to its great contrast and reproduces details in color very well due to its good color gradient.

The 6000:1 native contrast ratio allows the TV to reproduce dark scenes particularly well. It is easily one of the best in this price range – it’s often compared to high-end counterparts.

The S517 has superb black uniformity and contrast that create pleasant, deep blacks. They are much better than those of the similarly-priced competitors. The maximum deviation sits at around 1.02% .

The TV is good at capturing small differences in color such as skin tones, green colors in nature, details in shadows, etc. This is because of the color gradient, which is on par with other options of the same price. There is almost no banding and the standard deviation of color doesn't go past 0,11%.