The TCL C645K is a feature-packed 4K HDR TV that’s a strong choice for anyone looking for big-screen fun on a budget
- Accurate SDR and HDR images
- Comprehensive HDR support
- Very low input lag
- HDR could be brighter
- Not ideal for next-gen gamers
The TCL C645K marks the entry point into the brand’s QLED lineup, offering most of the benefits associated with a modern 4K HDR TV while keeping the price as competitive as possible.
This smart TV supports every HDR format and comes in sizes up to a massive 85in, making it a great choice for anyone who wants to enjoy films on a large screen but with a minimal outlay.
TCL C645 review: Key specifications
|Screen sizes available:||43in 43C645K|
|Resolution:||4K/UHD (3,940 x 2,160)|
|HDR formats:||Dolby Vision, HDR10, HDR10+, HLG|
|Audio enhancements:||Dolby Atmos, DTS Virtual:X|
|HDMI inputs:||HDMI 2.0b x 3|
|Tuners:||Terrestrial and satellite|
|Gaming features:||Game Master, ALLM|
|Wireless connectivity:||Wi-Fi, Bluetooth, Chromecast|
|Smart platform:||Android TV (11.0)|
|Freeview Play compatibility:||Yes|
|Smart assistants:||Built-in Google Assistant, works with Amazon Alexa|
TCL C645K review: What you need to know
The TCL C645K is a 4K (3,840 x 2,160) HDR smart LCD TV that comes in 43in, 50in, 55in, 65in, 75in and 85in screen sizes. It’s the entry point into TCL’s range of QLED TVs, uses a 60Hz VA panel with a direct LED backlight combined with quantum dot filters, and it’s very competitively priced.
The C645K runs Android TV and handles the HDR10, HLG, HDR10+ and Dolby Vision HDR formats. There’s also support for eARC, along with Dolby Atmos decoding and DTS Virtual:X processing. Google Assistant is built in, the TV works with Alexa, and there’s a comprehensive choice of streaming apps.
The gaming features aren’t as impressive as higher-ranked TCL TVs due to panel and HDMI limitations, but there are the latest Game Master gaming enhancements, support for Auto Low Latency Mode (ALLM) and an extremely low input lag when the C645K is in Game Mode.
TCL C645K review: Price and competition
The TCL C645K is very competitively priced. At the time of writing, you can the 43in model for £319, the 50in version for £337, the 55in TV for £399, the 65in screen size reviewed here for £579, and the 75in whopper for £899, while the jumbo 85in panel retails for a very reasonable £1,499.
In terms of competition, TCL is its own worst enemy, with the C745K offering exceptional performance and value for money. It’s more expensive across the three sizes it’s available in – 55in (£599), 65in (£749) and 75in (£1,099) – but the gaming features are significantly better, making it the ideal choice for film fans and more competitive gamers.
Other alternatives include the 55in Amazon Fire TV 4-Series at £430 (there isn’t a 65in option), and the 65in Samsung CU7100, which costs slightly more at £598. While both are decent TVs, the C645K has the edge in terms of performance, features, screen sizes and price.
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TCL C645K review: Design, connections and control
The TCL C645K offers a minimalist design, with a bezel-less screen and simple black trim around the outer edge. The construction is composed primarily of plastic but feels solid enough, and the 65in model is fairly chunky, measuring 1,444 x 82 x 835mm (WDH) without the feet attached.
The TV uses a pair of silver feet that offer two installation options, giving you the choice of attaching them wide apart or closer together for narrower surfaces. There’s only 50mm of screen clearance, but if you’d rather wall-mount the C645K, it’s compatible with a 300 x 300 VESA bracket.
The connections mainly face sideways, on the right-hand side as you look at the screen, and are far enough away from the edge to ensure you can’t see any cables. There are three HDMI inputs, a USB 3.0 port, terrestrial and satellite tuners, a common interface slot, an AV adapter and a headphone jack. Facing rearwards, you’ll find an optical digital output and an Ethernet port, while wireless connectivity is covered by Wi-Fi, Bluetooth and Chromecast.
The three HDMI inputs are 2.0b, which means they support 4K/60Hz, HDR10, HLG, HDR10+, Dolby Vision and ALLM (Auto Low Latency Mode). One of the inputs also supports eARC, but the inability to handle 4K/120Hz and VRR (Variable Refresh Rate) limits the C645K’s potential for those who game with PC rigs or the latest consoles.
The ergonomically shaped remote primarily uses icons to identify the various buttons, and these are all sensibly laid out. It’s comfortable to hold and easy to use with one hand, and includes direct access buttons for Netflix, Prime Video, YouTube, Internet and a pair of TCL-specific apps.
TCL C645K review: Smart TV platform
The TCL C645K uses the Android TV (11.0) operating system, as opposed to the newer Google TV found on the brand’s higher-range models. Despite this, the inclusion of a quad-core processor means there’s sufficient power to run the platform in a smooth, stable and responsive manner.
All the main video streaming apps are on offer, including Netflix, Prime Video, Disney+, Apple TV+, Now, YouTube, Google Play and all the TV catch-up services. There’s also support for resolutions up to 4K, along with HDR10, HDR10+, Dolby Vision, Dolby Atmos and DTS audio where available.
Google Assistant is built in, turning the C645K into a fully functioning smart assistant with voice control, plus there’s support for Chromecast and Google Home. In addition, the TCL works with Amazon Alexa and offers extensive file support for the built-in media player.
The TV tuner includes access to an EPG (electronic programme guide) that’s sensibly laid out and easy to use. One strange quirk is that the TV tuner defaults with the subtitles turned on, so unless you want to use them, you’ll need to go into the EPG and turn the subtitles off for all programmes.
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TCL C645K review: Image quality
The TCL C645K uses a VA LCD panel based on its black levels and narrow viewing angles, which is combined with a direct LED backlight. While there’s no form of local dimming, the screen uniformity is generally good, although there was a little clouding apparent on darker images.
The TV ships in Standard mode, and as is usually the case, this results in a highly inaccurate picture when compared to the industry standards, with an excess of blue in the greyscale, an uneven gamma and over-saturated colours, resulting in average Delta Es (errors) of 10 for both standards.
Switching to the Filmmaker mode improves matters, reducing the average Delta E in the greyscale to 3.7, and delivering colours that track their saturation points accurately. The gamma is also better, closely matching the target of 2.4. It’s not perfect, but it’s good enough for most people.
The visible threshold for any Delta E is 3, so the C645K is certainly in the ballpark, and at this price point, it’s unlikely to be calibrated. However, TCL includes a full set of calibration controls, and simply tweaking the greyscale in Filmmaker mode results in an error of only 0.8.
The picture is very watchable, with natural-looking colours and some decent shadow detail. Since the backlight is global rather than employing local dimming zones, the TV struggles in a darkened room, but the VA panel helps and some ambient lighting immediately improves the contrast.
Motion clarity is also good, given the inherent limitations of LCD as a display technology and the panel’s 60Hz refresh rate. As a result, there’s some blurring on fast motion such as sport, but the C645K handles 24p content without introducing judder.
The video processing and upscaling are also impressive and do a decent job of upscaling lower-resolution content to match the 4K panel, while the processing also helps minimise any of the nasty compression artefacts found on standard-definition broadcasts or low-quality streaming services.
TCL C645K review: HDR performance
The TCL C645K supports every version of HDR – HDR10, HLG, HDR10+ and Dolby Vision, which is very welcome at this price. It means never having to compromise, no matter which version a specific source is using, and the dynamic metadata in HDR10+ and Dolby Vision allows the TV to transcend its inherent limitations when tone-mapping HDR content.
As far as those limitations go, the biggest is obviously the peak brightness, with the C645K hitting just under 500cd/m2 on both a 10% window and a full-field pattern, regardless of which mode you select. As a result, with HDR content you’re better off choosing the Dark mode, which delivers a very accurate greyscale performance, impressive colour tracking and excellent tone mapping.
The use of quantum dot filters means the C645K covers the majority of the DCI-P3 colour gamut, reaching an impressive 95%. The colours also closely hit their targets at various saturation points, ensuring that the overall pictures look natural while also retaining a pleasing degree of pop. In terms of raw measurements, this is an impressive HDR performance for a TV at this price.
With actual material, the C645K continues to impress, rendering the fine detail in native 4K content and tone mapping accurately with 1,000 nits content, although there was clipping on material graded at 4,000 or 10,000 nits. This isn’t an issue with HDR10+ or Dolby Vision content, and given all streamers use one of these formats, as do a lot of 4K Blu-rays, this TV has you covered.
A film like The Flash looks extremely good, with all the detail in the 4K image delivered with clarity, while the comic book colours enjoy significant levels of impact. The frequent lightning that accompanies Barry’s super-speed is free of clipping and well defined, while the capable motion handling ensures that you can still see what’s going on no matter how frenetic the action gets.
To test the TCL C645K we used Portrait Displays Calman colour calibration software.
TCL C645K review: Gaming
The TCL C645K has a couple of strengths that make it a solid TV for gaming. The input lag in Game mode is extremely low at only 10ms, which is comparable with the best gaming TVs. Second, there’s no danger of image retention or screen burn-in with the LCD panel.
However, the lack of HDMI 2.1 means the C645K can’t support some of the latest gaming features such as 4K/120p HFR (High Frame Rate) and VRR (Variable Refresh Rate). It can at least handle ALLM (Auto Low Latency Mode), which means the TV switches into Game mode when a console is detected. TCL’s Game Master also adds a number of gaming-related features.
Overall the gaming performance is good, with the low input lag resulting in a responsive and enjoyable experience. The 4K images appear detailed, the 60Hz motion is pleasingly smooth, the colour gamut is punchy, and the HDR images are good despite the TV’s brightness limitations.
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TCL C645K review: Sound quality
The TCL C645K sports a sound system based around a pair of downward-firing full-range speakers, each of which has 15W of built-in amplification. The sound quality is surprisingly good, with a clean delivery and well-defined mid-range. Dialogue is clear, but there’s little in the way of bass extension, and the TCL can sound strained at higher volumes. However, the larger screen size adds some much-needed width, and there’s excellent stereo separation with music.
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The C645K also supports Dolby Atmos and DTS Virtual:X, with the latter being something of a rarity on TVs these days. While both are welcome, they can’t work miracles with only two downward-firing speakers, but at least they give the audio a greater feeling of dimensionality. If you have the necessary budget, you definitely should consider pairing this TV with an equally inexpensive but effective soundbar to create a big soundstage to complement the screen size.
TCL C645K review: Verdict
TCL has been knocking it out of the park this year and the C645K is another strong entry in its lineup. Picture quality is impressive, there are plenty of features on offer and an extensive choice of panel sizes, all of which are very aggressively priced.
If you want a really big screen for watching films, the C645K is a great choice with its detailed 4K images and comprehensive HDR support. However, serious gamers are better off spending a bit more on the superb TCL C745K with its awesome next-gen capabilities.