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- Surprisingly strong picture quality
- TiVo is content-rich and easy to use
- Amazingly cheap for what it offers
- Sound is a bit thin
- Mild backlight clouding in dark scenes
- Awkwardly wide foot placement
After a few years in the relative wilderness, Sharp has returned to the UK AV fray with a bang in 2025 with a series of TVs and soundbars that have managed to ramp up the brand’s performance game without impacting its reputation for delivering some of the most aggressively priced home entertainment gear in town.
In fact, its GK4245K TV series is arguably the single most appealing proof of Sharp’s newfound combination of quality and affordability. Especially the 70in model that I tested, which delivers its big-screen thrills for under £470.
Sharp GK4245K: Key specifications
| Screen sizes available | 43in (43GK4245K), 50in (50GK4245K), 55in (55GK4245K) and 70in (70GK4245K) |
| Panel type | VA LCD |
| Resolution | 4K/UHD (3,840 x 2,160) |
| Refresh rates | 60Hz |
| HDR formats | HDR10, HLG, Dolby Vision |
| Audio enhancement | 2 x 10W stereo speaker system, Dolby Atmos |
| HDMI inputs | 3 x HDMI (one with eARC) |
| Freeview Play compatibility | Yes (and Freely) |
| Tuners | Terrestrial Freeview HD |
| Gaming features | Dolby Vision Gaming, VRR, ALLM, 4K/60Hz (HDR), 1080/120Hz (SDR) |
| Wireless connectivity | Wi-Fi |
| Smart platform | TiVo |
What you need to know
The GK4245K range is four-strong, aggressively priced and equipped with both the TiVo and Freely smart platforms.
While you inevitably have to swallow a few price-based compromises along the way, the GK4245K manages to deliver a few unexpected bonus features, including Dolby Atmos sound playback and Dolby Vision high dynamic range support, while at the same time delivering pictures for both gaming and movies that make their knock-down prices look almost silly.
Price and competition
The GK4245K sits very much at the budget end of the TV world, with the 43in, 50in, 55in and 70in models available costing just £199, £259, £379 and £469 respectively. The 70in set for under £470 is a particular head turner, but all four potentially represent excellent value for money when you take into account their Freely and TiVo smart systems.
Equally affordable rivals are unsurprisingly fairly thin on the ground. The TCL P7K, which I reviewed recently, fits the bill, though, delivering 50in, 55in, 65in and 75in sets for just £299, £379, £499 and £599. These TCLs don’t carry Freely or TiVo smarts, but they’re still enjoyable to watch, use a quantum dot colour system, which the Sharp models do not, and their Google TV systems certainly carry lots of content, even if they’re not the easiest to use.
Design, connections and control
The GK4245K is one of the lightest TVs I’ve ever tested; the 70in model proved pretty easy for me to hoik around by myself. Basically, if robust build quality were a reliable indicator of how good a TV might be, the GK4245K would be in trouble before I’d even switched it on.
It’s quite chunky around the back by modern TV standards, making it a rather cumbersome wall-mounting option, and the way its feet attach near the screen’s bottom corners means you’ll need a pretty big bit of furniture to put it on, especially with the 70in set, if you don’t go the wall-hanging route.
The GK4245K’s top, left and right screen borders are reasonably trim, though, while the shiny finish applied to the wider bottom edge just about makes you forget that everything is made of lightweight plastic.
The available connections only stretch to three HDMI ports rather than the four typically found on more premium TVs. What’s more, since the GK4245K uses a 60Hz panel, the HDMIs don’t support the data bandwidths necessary for the full set of modern video game features.
That said, the HDMIs do have one unexpected trick up their sleeve as a connected Xbox Series X revealed them to be capable of taking in SDR (but not HDR) 1080p graphics at 120Hz refresh rates. This is presumably achieved using ‘dual line gate’ technology, where two lines of pixels are displayed at once (hence the reduced resolution required for 120Hz support) on the 4K screen instead of just one, and it really does work. Though, as we’ll see in the gaming section of the review, it comes with strings attached.
Other connections on the GK4245K are limited to an optical digital audio output, RF and satellite inputs, a 3.5mm headphone jack, an RJ45 LAN port, and a pair of USBs that are capable of playing an impressively wide range of video, music and photo formats.
The GK4245K ships with a remote control that’s as flimsily built as the TV. It tries to hide its fundamentally cheap build by sticking a faux metallic fascia to the remote’s front edge and shiny silver (though still plastic) highlighting over the main menu navigation controls.
Smart TV platform
The GK4245K’s smart features are delivered by a combination of TiVo and Freely. Looking at TiVo first, while its presentation is deceptively simple, it does a much more sophisticated job of finding and recommending content that you might be interested in than many more powerful systems. It also runs smoothly and slickly at all times, despite the relatively low-end TV it’s running on. Best of all, it features what is for me the most effective voice recognition system around when it comes to understanding context, conversational speech and making useful connections when answering content search requests.
TiVo is also pretty rich in content, carrying almost all of the main video streaming services. The only major absentee is a dedicated Apple TV app. If you need this, it’s now available through the Prime Video app.
Freely was launched in 2024 by the UK’s ‘big four’ terrestrial broadcasters to live stream most of the channels previously only available through an aerial or set-top box. All of the BBC, ITV, Channel 4 and Channel 5-owned channels found on Freeview are also on Freely, along with many tens of thousands of hours of on-demand content. Several other content providers have also signed up since the service launched, with others being added pretty regularly.
Getting both TiVo and Freely on a TV as affordable as the GK4245K really does feel like quite a boon.
Image quality
The promising vibes established by the GK4245K kick up a gear when you settle down to watch its pictures. The good news starts with the objective fact that, despite how cheap it is, this telly can deliver a remarkably accurate SDR image if you select its Movie preset.
Measurements of this mode using Portrait Displays’ Calman Ultimate software, G1 signal generator, and C6 HDR5000 spectrometer find two-point and Multi-point grayscale tests getting the ball rolling with Delta E 2000 average errors of just 3.3 and 3.4, on a scale where any measurement of three or less represents so little deviation from the industry standards that the human eye won’t notice it.
Things just get better from there, with Calman’s colour gamut test revealing a Delta E 2000 average error of just 1.8 across eight measurement points, while colour checker, saturation sweep and luminance sweep tests hit scores of just 2.4, 1.7 and 2.2. All comfortably under that target figure of 3.
Sharp has limited the GK4245K’s peak white level to around 190cd/m2 in Movie mode (only just over half the brightness the screen tracks to with its more aggressive Dynamic and Natural picture presets) to achieve such accurate results, but pictures are still bright enough to be enjoyable, at least in a dark room.
Limiting brightness also helps the GK4245K achieve better black levels in Movie mode than it does in its brighter presets, and it does this without shadowy details disappearing into the blackness. Colours, meanwhile, look rich enough in Movie mode not to leave the image feeling dull or flat, and native 4K SDR sources enjoy impressive sharpness and texturing. This sharpness doesn’t fall apart too badly when there are camera pans or moving objects to handle, either. There’s a touch of resolution loss over large moving objects, but it’s not severe, and isn’t joined by either excessive hardware judder (even with 24p film sources) or smearing.
Unexpectedly good though the GK4245K’s ability to deliver accurate pictures is, I was also excited by how well it switches gears to more punchy images with its Natural and Dynamic presets. Brightness jumps up to 335cd/m2 and 323cd/m2, respectively for these SDR presets, and if anything, my eyes perceived the brightness as even higher than that. Colour saturations remain vibrant in these brighter modes too, rather than paling away as can happen with some budget TVs that push brightness further than their colour systems can handle.
Dark scenes contain a little more greyness in these brighter presets, but shadow detailing remains strong, and bright areas of mostly dark shots retain enough intensity to distract you from the greyer-looking dark bits.
Colours still tend to look balanced even in the punchier Natural/Dynamic modes, while sharpness is even better than it was in Movie mode. I was also struck by how little (relative to the rest of the budget LCD TV world) contrast and colour saturations were impacted by off-axis viewing.
These modes can reveal faint traces of clouding inconsistency in a couple of screen areas, but this is faint at the best of times and invisible with any remotely bright image. Aside from that niggle, the only other negatives I can point out in the pictures are that upscaled HD pictures look a bit soft, and that the Natural and Dynamic presets don’t track SDR video standards nearly as accurately as the Movie mode. The Natural Mode turns in Calman Ultimate Delta E 2000 average errors of 11.9 and 10.3 for 2-point and multipoint greyscale tests, 7.1 for the colour gamut test, and 7.2, 8.9 and 5.9 for Colour Checker, Saturation Sweep and Luminance Sweep tests. The Dynamic Mode results go further astray across every test.
Finishing this section on the positive note the GK4245K deserves, it turns out it’s capable of covering a very respectable 98.5% of the BT.709 SDR colour spectrum.
HDR performance
The GK4245K holds up better than most budget rivals with HDR content. Despite only having a global dimming backlight with no local LED cluster controls, it manages to find a little extra light, at least in its Natural preset, for HDR playback. A 10% HDR peak luminance test window sees the GK4245K hit exactly 350cd/m2, which creeps up to around 360cd/m2 from a 25% window; a measurement that holds steady right through to a full 100% luminance window.
Colours enjoy a bit more solidity and vibrancy with HDR sources than they do in the TV’s brightest SDR modes, too. However, the panel lacks a quantum dot colour filter, and its limited peak brightness stops it from producing the sort of explosive colour volumes that a premium HDR performer might. Sharp’s set does do a nice job of retaining good levels of shading subtlety in the range of colour it CAN cover (a measured 80.6% of the DCI-P3 HDR spectrum), though. Even in the Dynamic preset.
Dark scenes look greyer on the GK4245K with HDR content than they do with the SDR Movie mode, as HDR’s much greater light range gives the global dimming system far fewer opportunities to take a breather than SDR does. The areas of clouding slightly visible with some SDR picture modes are more consistently present and defined in HDR, too.
These extraneous light issues vanish entirely with bright images, and can be mitigated by not watching the TV in a totally dark room. But they’re distracting enough to become the only reason the GK4245K gets four stars rather than a budget-tastic five. One other little issue with the backlighting with HDR is that while it’s great to see Dolby Vision HDR supported, the oddly calibrated Dolby Vision Dark picture mode can cause background details in very dark shots to be crushed out of the picture.
The pictures get back on track with their sharpness, though, looking slightly denser and more detailed with 4K sources than they do with SDR content, presumably because of the expanded contrast HDR images enjoy.
While all of the HDR picture presets are very watchable despite a few backlight limitations, Calman Ultimate tests reveal that, as with SDR, only the Movie mode tries to closely track the established HDR video standards. And even that mode gets off to a slightly rough start by returning a DeltaE 2000 error result of 12 on Calman’s ColorMatch test. The ColorChecker Analysis test sees the average error level plummet to a very respectable 4.6, while I measured BT.2020 and P3 colour sweeps at 5.4 and 4, respectively. Many far more expensive TVs don’t do HDR as accurately as that.
The Natural mode measures marginally better than the Movie mode with the ColorMatch HDR signal, but doesn’t quite do as well with ColorChecker Analysis (5.9) and P3 Saturation Sweeps (7). And the Dynamic mode, as with its SDR iteration, trades a bit more accuracy again in return for its more exaggerated images.
None of the measurements I recorded in any HDR preset are truly terrible by today’s TV standards, and the pictures in Natural and Dynamic mode are always subjectively seriously watchable. Meanwhile, the Movie mode is always there to give you more accuracy than you’ve any right to expect for so little money.
Gaming
As mentioned earlier, despite using a native 60Hz panel, the G4245K can play 120Hz games at 1080p resolutions via line doubling. This really does work, delivering 120Hz FHD games without judder, stutter or tearing. There are two major catches, though. First, high dynamic range support is dropped in 120Hz mode, and second, the reduction in resolution required to make the 120Hz frame rate possible is really quite noticeable. In the end, I personally preferred to stick to 4K/60Hz gaming with HDR.
The G4245K supports variable refresh rates and can detect when it’s receiving a game rather than a video source and automatically switch into Game mode. In this mode, the screens take a respectably speedy 14.8ms to render 60Hz graphics.
In 4K/60Hz mode, the tidy collection of talents that serve the GK4245K so well for video also contribute to an engaging gaming performance. Graphics look sharp, motion isn’t affected badly by the TV’s slight motion blur, even at 60Hz, colours look punchy and well defined, and dark game areas look detailed and black enough to both convince and allow you to spot hiding enemies.
To test the Sharp GK4245K, I used Portrait Displays Calman colour calibration software.
Sound quality
The G4245K’s sound doesn’t punch above its price weight as its pictures do. There just isn’t enough power to allow the sound to escape from the confines of the TV’s bodywork with compelling amounts of volume, dynamic range, detail or impact. Vocals can sound a bit dislocated from the visuals too, and if you were hoping for meaty explosions, dinosaur footfalls and the like, you’re in for quite the bass-free disappointment.
While adding a soundbar to your GK4245K is highly recommended, though, I can at least report that the speakers don’t fall into the common budget TV trap of trying to deliver more dynamic range and volume than they’re really capable of. Meaning they don’t succumb to such common TV speaker nasties as crackling, buzzing, popping or outright distortion.
Verdict
Despite some flimsy bodywork and audio, Sharp’s GK4245K easily became the latest honorary member of the ‘How do they do so much for so little money?’ club that’s seen its numbers swell so considerably this year.
TiVo and Freely smarts add up to a fantastically content-rich and user-friendly way of navigating today’s online world, and while a little backlight clouding prevents the TV from earning five-star status, the panel belies its basic on-paper spec to deliver consistently enjoyable and engaging pictures, especially on the 70in I tested.
