The TCL QM8/QM851G QLED is the highest-end offering in TCL's 2024 North American QLED lineup and sits above the TCL QM7/QM751G QLED. It uses TCL's AIPQ Engine Gen3 processor and is advertised as being over twice as bright as its predecessor, with up to 5000 dimming zones depending on the size. The TV is loaded with features like Dolby Vision and HDR10+, HDMI 2.1 bandwidth, 4k @ 144Hz, 1080p @ 240Hz, and VRR support. It uses the Google TV interface that's loaded with apps and has other smart features like voice control, and it comes with a backlit remote. It has a built-in 2.1.2 channel ONKYO speaker system and supports Dolby and DTS advanced audio formats. We bought and reviewed the 65-inch model, but it's available in four different sizes: 65, 75, 85, and 98-inch.
Our Verdict
The TCL QM851G is great for mixed usage. It has superb SDR brightness and fantastic reflection handling, making it suitable for even the brightest rooms. It also looks outstanding in a dark room, with very deep blacks that stay deep when bright highlights are also on screen. Highlights in HDR content really stand out, so watching movies or playing games in HDR is very impactful. Fast motion has minimal blur due to the TV's excellent response time, which makes it suitable for sports, games, or for use as a PC monitor. Unfortunately, it has a narrow viewing angle, so it's not a good choice for watching TV with a group of friends or family.
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Outstanding contrast delivers deep blacks in a dark room.
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Remarkable HDR brightness for very bright highlights.
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Fantastic reflection handling and superb SDR brightness makes it suitable for very bright rooms.
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Excellent response time for minimal blur behind fast motion.
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Image degrades when viewed from the sides.
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Is a bit buggy at times.
The TCL QM851G is very good for watching TV shows. The built-in Google TV OS is loaded with apps, so finding your favorite shows is easy. If you have older shows on DVD or you're stuck watching low-quality or low-resolution streams, the TV's image processing does a great job of smoothing out artifacts and a good job at upscaling. It has superb SDR brightness and fantastic reflection handling, so it easily overcomes glare in even the brightest of rooms. Unfortunately, the TCL has a very narrow viewing angle, so the image degrades when viewed from the sides of the screen. This makes it a bad choice for watching shows with friends.
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Fantastic reflection handling and superb SDR brightness makes it suitable for very bright rooms.
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Excellent response time for minimal blur behind fast motion.
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Great low-quality content smoothing and good upscaling capabilities.
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Image degrades when viewed from the sides.
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Is a bit buggy at times.
The TCL QM851G is very good for watching sports. The TV's superb SDR brightness and fantastic reflection handling mean it overcomes glare in even the brightest rooms. Its excellent response time means there's minimal blur behind fast-moving players or objects, and it has very good gray uniformity, so you aren't overly distracted by the dirty screen effect when watching sports with large areas of uniform color, like hockey. Unfortunately, it's not a good choice for watching the game with friends since it has a narrow viewing angle; anyone watching from the sides of the screen sees a degraded image.
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Fantastic reflection handling and superb SDR brightness makes it suitable for very bright rooms.
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Excellent response time for minimal blur behind fast motion.
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Great low-quality content smoothing and good upscaling capabilities.
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Image degrades when viewed from the sides.
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Is a bit buggy at times.
The TCL QM851G is fantastic for playing video games. It has incredibly low input lag for a responsive gaming experience, and its excellent response time means it displays quick motion with minimal blur. Enabling Game Mode has no impact on picture quality, so you can enjoy the best possible performance without sacrificing image quality. It's also a great TV to pair with modern consoles or gaming PCs since it has HDMI 2.1 bandwidth and supports up to 4k @ 144Hz. It also supports VRR, but there's a distracting issue when the TV hovers around 65Hz.
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Fantastic reflection handling and superb SDR brightness makes it suitable for very bright rooms.
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HDMI 2.1 bandwidth, 4k @ 144Hz, 1080p @ 240Hz, and VRR support.
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Excellent response time for minimal blur behind fast motion.
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Incredibly low input lag for a very responsive experience.
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Is a bit buggy at times.
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VRR issues around 65Hz.
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Can't have both chroma 4:4:4 and Game Mode enabled at the same time.
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Only one port is capable of 4k @ 144Hz and 1080p @ 240Hz.
The TCL QM851G is excellent for watching movies in a dark room. It has outstanding contrast that delivers deep blacks that stay deep when highlights are also on screen, and it has remarkable HDR brightness, so highlights in HDR content really stand out. Colors are also vibrant, lifelike, and bright in HDR due to the TV's wide color gamut and outstanding color volume. The TV automatically removes 24p judder from all sources, so you get a judder-free experience no matter how you watch your movies. The TCL has very good SDR accuracy without calibration, but those looking for the most accuracy possible will still want to get it calibrated.
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Outstanding contrast delivers deep blacks in a dark room.
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Remarkable HDR brightness for very bright highlights.
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Automatically removes 24p judder from any source.
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Wide color gamut and outstanding color volume for vibrant, lifelike, and bright colors.
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Dolby Vision and DTS audio support.
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Great low-quality content smoothing and good upscaling capabilities.
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Image degrades when viewed from the sides.
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Is a bit buggy at times.
The TCL QM851G is fantastic for playing games in HDR. It has outstanding contrast and remarkable HDR brightness, so blacks are deep and highlights really pop out in HDR. Using Game Mode doesn't affect the image, so you can enjoy the best gaming performance without trading in picture quality. The TV has incredibly low input lag, so there's no noticeable delay between your controller inputs and the action on screen. You also get minimal blur behind fast motion due to its excellent response time. It has HDMI 2.1 bandwidth, up to 4k @ 144Hz, and supports VRR, so it's an excellent option for those looking to get the most out of their modern consoles or gaming PCs. Unfortunately, there's a distracting issue when the TV hovers around 65Hz when using VRR.
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Outstanding contrast delivers deep blacks in a dark room.
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Remarkable HDR brightness for very bright highlights.
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Wide color gamut and outstanding color volume for vibrant, lifelike, and bright colors.
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HDMI 2.1 bandwidth, 4k @ 144Hz, 1080p @ 240Hz, and VRR support.
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Incredibly low input lag for a very responsive experience.
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Is a bit buggy at times.
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VRR issues around 65Hz.
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Can't have both chroma 4:4:4 and Game Mode enabled at the same time.
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Only one port is capable of 4k @ 144Hz and 1080p @ 240Hz.
The TCL QM851G is excellent for use as a PC monitor. It easily overcomes glare in a bright room due to its superb SDR brightness and fantastic reflection handling. The TV's fantastic response time means there's minimal blur behind quick cursor movements, and its incredibly low input lag provides a responsive desktop experience. You aren't overly distracted by the dirty screen effect when looking at large areas of uniform color, like when browsing the web, due to its very good gray uniformity. Unfortunately, it has a narrow viewing angle, so the sides of the screen aren't uniform with the center when you sit close. The TV displays chroma 4:4:4 properly, but it uses a BGR subpixel layout that impacts the text clarity, although not everyone will be bothered by this.
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Fantastic reflection handling and superb SDR brightness makes it suitable for very bright rooms.
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Excellent response time for minimal blur behind fast motion.
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Incredibly low input lag for a very responsive experience.
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Image degrades when viewed from the sides.
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Is a bit buggy at times.
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Can't have both chroma 4:4:4 and Game Mode enabled at the same time.
- 8.5 Mixed Usage
- 8.0 TV Shows
- 8.1 Sports
- 9.0 Video Games
- 8.7 HDR Movies
- 9.0 HDR Gaming
- 8.7 PC Monitor
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Updated Nov 20, 2024:
We retested the TV's PQ EOTF tracking with firmware T653T02-LF1V107, and there's no difference in performance. We'll be retesting it again when FW113 is available.
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Updated Oct 16, 2024:
We changed the TV's Native Refresh Rate to match its maximum refresh rate at its native resolution in the Variable Refresh Rate section of this review.
- Updated Aug 16, 2024: We updated the Stand section to add information about the two adjustable heights of the stand.
- Updated Jul 16, 2024: Review published.
- Updated Jul 11, 2024: Early access published.
- Updated Jun 27, 2024: Our testers have started testing this product.
- Updated Jun 13, 2024: The product has arrived in our lab, and our testers will start evaluating it soon.
- Updated May 29, 2024: We've purchased the product and are waiting for it to arrive in our lab.
Differences Between Sizes And Variants
We bought and tested the 65-inch TCL QM8/QM851G QLED (65QM851G), and these results are also valid for the 75, 85, and 98-inch models. The larger models perform similarly, although they should have better dark scene performance than the 65-inch model due to having more local dimming zones. The TCL QM851G is currently only available in North America; in Europe, TCL released the similar TCL X955. Typically, similar models from other regions perform differently, so these results aren't valid for it.
Note: TCL hasn't yet confirmed the number of dimming zones of each model size. We'll update this table as we find out how many dimming zones each size has.
| Size | Model | Dimming Zones |
|---|---|---|
| 65" | 65QM851G | 2880 |
| 75" | 75QM851G | Currently Unknown |
| 85" | 85QM851G | Currently Unknown |
| 98" | 98QM851G | Currently Unknown |
Our unit was manufactured in April 2024; you can see the label here.
Compared To Other TVs
The TCL QM8/QM851G QLED is a great TV overall that's affordable and is loaded with pretty much any feature you can ask for. It provides excellent overall picture quality whether you're streaming shows, watching sports on cable, watching movies on physical media, or playing video games. Unfortunately, it's held back by its inconsistent VRR feature and the fact that HDMI 1 is the only port capable of 144Hz and 240Hz, which limits its usefulness for gaming. It's very similar to the Hisense U8/U8N, but the QM851G is even brighter overall. However, the Hisense has slightly better reflection handling with no rainbow smearing. The Hisense also has better contrast and is the more accurate TV of the two, so it delivers deeper blacks and sticks closer to the content creator's intent in both SDR and HDR. Since the Hisense is already bright enough for pretty much any well-lit room and to take advantage of most HDR content, the majority of people are better off going with that TV. Still, the QM851G has better overall picture quality and more features than more expensive models from manufacturers like Sony, Samsung, and LG, and it's cheaper.
For more options, check out our recommendations for the best TVs for bright rooms, the best 65-inch TVs, and the best TVs for gaming.
The TCL QM8/QM851G QLED is better than the TCL QM7/QM751G QLED. With a few exceptions, notably viewing angle and PQ EOTF tracking, the QM8 does everything better than the QM7. The QM8 is noticeably brighter in HDR and SDR, has better contrast, and is more accurate in SDR prior to calibration. It also has much better reflection handling than the QM7, making it a far better option if you like to watch TV in extremely bright rooms. Overall, the 2024 QM8 is a noticeable upgrade over the QM7.
The Hisense U8/U8N and the TCL QM8/QM851G QLED are similar TVs, but the Hisense is slightly better overall. With local dimming enabled, the Hisense displays deeper blacks in a dark room due to its higher contrast ratio. The Hisense also has better accuracy in SDR and HDR, so it sticks closer to the content creator’s intent. On the other hand, the TCL is the brighter TV overall, but it has slightly worse reflection handling than the Hisense, so the two TVs perform similarly in a bright room.
The Hisense U8/U8K and TCL QM8/QM851G QLED are evenly matched, with only small differences. The TCL is a bit brighter in HDR and SDR, but the Hisense is more accurate in HDR and SDR. The TCL has slightly better image processing. Gamers might prefer the TCL, which has a noticeably faster response time than the Hisense. Ultimately, the Hisense is the better choice if you care about image accuracy. Otherwise, the TCL offers a slightly brighter image.
The TCL QM8/QM851G QLED is better than the Sony X90L/X90CL. The TCL has better contrast, with better-blooming performance and superior lighting zone transitions. It's also significantly brighter than the Sony in HDR, with a wider color gamut. The TCL is also a bit brighter in SDR but has far better reflection handling, making it the superior choice in bright rooms. The Sony does have better PQ EOTF Tracking and upscaling, but otherwise, it's outperformed in most ways by the TCL.
The LG C3 OLED is better than the TCL QM8/QM851G QLED, but they excel in different room conditions. Being an OLED, the LG is fantastic in dark rooms due to its near-infinite contrast, with no blooming or lighting zone transitions. The TCL, however, is far brighter in HDR and SDR, making it the better choice in brighter rooms. Still, the LG is more accurate in HDR and SDR, has better image processing, and is the better gaming TV due to its near instantaneous response time, so it doesn't really have any weaknesses outside of its lower brightness.
The TCL QM8/QM851G QLED is noticeably better than the older TCL Q7/Q750G QLED. As the TCL QM8 is a higher-end model than the Q7, it outperforms it in every metric except one: the Q7 is more accurate than the extremely bright QM8 in HDR. Otherwise, the QM8 is just better, although it's also typically sold for a higher price.
The LG C4 OLED is better than the TCL QM8/QM851G QLED. The LG has perfect contrast, so it displays inky blacks with no blooming at all. When it comes to accuracy, the LG displays an image that is much closer to the content creator’s intent in SDR and HDR. The LG also has a much wider viewing angle, so it’s the better option for watching TV with a group, and it has better image processing. Additionally, the LG has a faster response time for less blur behind quick motion. However, the TCL is the much brighter TV, so if you need a TV for use in a very bright room, it’s the better option.
The TCL QM8/QM851G QLED is slightly better than the Samsung QN90C/QN90CD QLED. The TCL has better contrast, with less blooming and less visible lighting zone transitions. The TCL even has a slightly wider color gamut. And while the Samsung is very bright, the TCL is even brighter in HDR content. That comes at a cost, however, as the Samsung is, in turn, much more accurate in HDR. The Samsung also has a surprisingly decent viewing angle for an LED TV, while the TCL's viewing angle is disappointing. Overall, the TCL TV looks more vibrant in most content.
The TCL QM8/QM851G QLED is a bit better than the Sony BRAVIA 7 QLED, but it's very close. The TCL is the brighter of the two TVs, with better contrast and a faster local dimming solution, giving it the edge in most room contexts. Still, the Sony model is vastly more accurate in HDR and slightly less so in SDR, and it also has better image processing, so it's the better TV for those who care most about the content creator's intent. Regarding gaming, the TCL is better due to its 4k @ 144Hz and 1080p @ 240Hz support, while the Sony is limited to 4k @ 120Hz.
The Sony BRAVIA 9 QLED is better than the TCL QM8/QM851G QLED. The Sony has better black uniformity and a better local dimming feature that gives it a higher contrast ratio, so it displays deeper blacks with less blooming. When it comes to accuracy, the Sony is a lot better in both SDR and HDR, so you get an image that is closer to the content creator’s intent, regardless of the format of the content. The Sony has better image processing, so low-quality and low-resolution content looks better on it, and colors have less banding. Both TVs don’t have the widest viewing angle, but the Sony’s is wider, so the image doesn’t degrade as quickly from the sides of the screen. On the other hand, the TCL gets brighter in HDR, so it can display some very bright highlights in HDR that the Sony can’t.
The TCL QM8/QM851G QLED is a bit better than the TCL QM8/QM850G QLED. The QM851G has better contrast, so it displays deeper blacks in a dark room, with a bit less blooming. The QM851G also gets brighter in HDR, so very bright highlights stand out a bit more on it. Additionally, the QM851G has better pre-calibration SDR accuracy, slightly better upscaling, and its color volume is a bit better. However, the QM850G has better PQ EOTF tracking, so it displays a more accurate image in HDR.
The 75-inch TCL QM8/QM851G QLED is mostly better than the Hisense 75U8N. The TCL's 75-inch model uses a VA panel, which helps it deliver much better contrast for deeper blacks, and it has less blooming. The TCL is also the brighter TV overall, so it displays brighter highlights in HDR content and overcomes more glare in a very bright room. When it comes to motion, the TCL is better due to its faster response time. However, the 75U8N has the wider viewing angle, so it's better suited for watching TV with a large group of friends.
The TCL QM8/QM851G QLED is mostly better than the LG QNED90T. The TCL is the brighter TV overall, so it fights more glare in a bright room and displays brighter highlights in HDR. The TCL displays more vibrant and lifelike colors due to its wider color gamut, and it can display those colors brighter due to its better color volume. The TCL also displays deeper blacks with less blooming, and it does a better job smoothing out low-quality content. However, the LG is the more accurate TV in SDR and HDR due to its better pre-calibration SDR accuracy and PQ EOTF tracking.
The TCL QM8/QM851G QLED is superior to the Panasonic W95A. The TCL gets brighter and has better reflection handling, making it more suitable for a bright room. The TCL also looks better in a dark room due to its superior contrast, and it displays brighter highlights and colors in HDR content. Finally, the TCL is better for gamers due to its faster response time, lower input lag, 144Hz refresh rate, and the fact that you can use local dimming with VRR enabled.
Video
Test Results
The TCL QM851G has a very similar design to last year's TCL QM8/QM850G QLED. It has thin bezels on the sides and the top, with a slightly thicker bottom bezel. Unfortunately, the bezels have a reflective finish. If you have lights on in your room, you see distracting reflections on the bezels. There's also branding near the top corner on the right bezel that uses reflective writing that can also be distracting in a well-lit room. Additionally, there's a fairly large gap between the bezels and the screen.
The TV comes with a metal center-mounted stand that doesn't require a large table to place the TV on. The stand holds the TV well and can be adjusted into two different positions. The higher position (pictured above) lifts it about 3.5 inches above the table, so most soundbars fit underneath without blocking the screen. The lower position adds a bit of stability and only lifts the TV about 2.23 inches, which is great if you don't have a soundbar and want the screen as close to your table as possible.
Footprint of the 65-inch stand: 13.46" x 11.73".
The back is made of plastic and has a grid-like pattern that's very reminiscent of current Sony TVs. Most of the inputs are side-facing, but they're located in a recessed cutout that makes them a bit hard to access if you have the TV wall-mounted. There are two speakers located at the top, and the TV has a built-in ONKYO subwoofer located in the middle of the back of the TV. You can also funnel cables through the TV's stand to help with cable management.
The TCL QM851G has great build quality. It's mostly made of plastic, but it's sturdy and well-built overall. The TV has the usual flex near the VESA mounting points on the back and it wobbles a bit when pushed on, but neither of these cause any problems. There's no issues with quality control on our unit.
The TCL QM851G has outstanding contrast. Its native contrast is great, but with local dimming enabled, the TV displays very deep blacks that stay deep when brighter highlights are also on screen.
The TV has excellent blooming performance, with only some minor blooming around bright objects and subtitles when displayed against a black background.
The TV has excellent lighting zone transitions, but it does struggle a bit with very fast-moving content. There's barely any haloing, but the leading edge of quick-moving objects is a bit dimmer.
There's no visible difference in dark scene performance when the TV is set to Game Mode.
The TCL QM851G has remarkable HDR brightness. Highlights really pop out during darker scenes, and it's bright enough that very bright specular highlights even stand out in well-lit scenes. Combined with its outstanding contrast, this TV provides a very impactful HDR viewing experience.
These measurements are after calibrating the HDR white point with the following settings:
- HDR Picture Mode: Movie
- Brightness: 100
- Contrast: 100
- Local Contrast: High
- Gamma: 2.2
- Micro Contrast: off
- Color Temperature: Warm -5
- Dynamic Tone Mapping: Off
The peak brightness in 'Vivid Mode' is even higher:
- Peak 2% Window: 4047 cd/m²
- Peak 10% Window: 3311 cd/m²
- Peak 25% Window: 3236 cd/m²
- Peak 50% Window: 1743 cd/m²
- Peak 100% Window: 924 cd/m²
- Sustained 2% Window: 2315 cd/m²
- Sustained 10% Window: 3204 cd/m²
- Sustained 25% Window: 3137 cd/m²
- Sustained 50% Window: 1738 cd/m²
- Sustained 100% Window: 923 cd/m²
There's no visible difference in brightness with most games when the TV is set to Game Mode. Highlights really pop out during darker moments in games, and it's bright enough that very bright specular highlights even stand out in well-lit games. Combined with its outstanding contrast, this TV provides a very impactful HDR gaming experience.
These measurements are after calibrating the HDR white point with the following settings:
- HDR Picture Mode: Game
- Game Master: On
- Brightness: 100
- Contrast: 100
- Local Contrast: High
- Gamma: 2.2
- Micro Contrast: off
- Color Temperature: Warm -5
- Dynamic Tone Mapping: Off
The TV is even brighter with 'Dynamic Tone Mapping (DTM)' turned on. Results with DTM set to Detail Priority:
- Hallway Lights: 1673 cd/m²
- Yellow Skyscraper: 857 cd/m²
- Landscape Pool: 848 cd/m²
Results with DTM set to Balance:
- Hallway Lights: 1658 cd/m²
- Yellow Skyscraper: 1026 cd/m²
- Landscape Pool: 882 cd/m²
Results with DTM set to Brightness Priority:
- Hallway Lights: 1583 cd/m²
- Yellow Skyscraper: 1104 cd/m²
- Landscape Pool: 902 cd/m²
The TCL QM851G has only okay PQ EOTF tracking. It favors brightness over accuracy, so content is displayed brighter than intended. There's a sharp cutoff near its peak brightness with content mastered at 600 and 1000 nits, but no roll-off is necessary since the TV is bright enough to fully display content mastered at those brightness levels. With content mastered at 4000 nits, there's a slight roll-off to maintain some detail in very bright specular highlights.
We retested the TV's PQ EOTF tracking with firmware V8-T653T02-LF1V107 and confirmed there was no difference in the results. We'll retest it again once FW113 is available.
The TCL QM851G has superb SDR brightness and easily overcomes glare in the brightest of rooms.
These measurements are after calibration with the following settings:
- Picture Mode: Movie
- Brightness: 100
- Contrast: 100
- Black Level: 50
- Dynamic Contrast: Off
- Black Stretch: Off
- Dynamic Brightness: Off
- Local Contrast: High
- Micro Contrast: Off
- Gamma: 2.2
The TCL QM851G has an excellent HDR color gamut. It has fantastic coverage of the commonly used DCI-P3 color space, although most colors are a bit undersaturated. The TV has very good coverage of the wider Rec. 2020 color space, but all colors are undersaturated, with highly saturated greens and cyans performing the worst.
The TV has outstanding color volume. It displays a wide range of colors at high luminance levels, and dark saturated colors are displayed well due to its outstanding contrast.
The TCL QM851G has very good pre-calibration accuracy. The color temperature is very close to our target of 6500K, and color accuracy is great, with only some inaccuracies with light yellows, light cyans, and whites. Its white balance is decent, but blues are overrepresented in darker shades of gray, and reds are overrepresented in all shades of gray. Gamma is pretty close to our target of 2.2, but all scenes are displayed brighter than intended.
The TV has fantastic SDR accuracy after calibration, and it's easy to calibrate. Gamma, white balance, and color temperature are now all essentially perfect. Color accuracy is outstanding, but there are still some very minor inaccuracies with darker blues.
You can see our full calibration settings here.
The TV has very good gray uniformity, but there's some dirty screen effect towards the center of the screen, and the corners are a bit darker than the center. On a very dark or near-black screen, its uniformity is excellent, but the corners of the screen are a bit lighter than the center.
The TCL QM851G has superb black uniformity. With local dimming disabled, blacks are slightly cloudy and blueish. With local dimming enabled, blacks are deep and uniform across the screen, with only a bit of blooming around bright objects on a dark background.
The TCL QM851G has an inadequate viewing angle, so it's not suitable for a wide seating arrangement. As you move off-center, there's significant gamma shifting, color shifting, and brightness loss, and colors look increasingly washed out as you move further away to the sides.
The TV has fantastic reflection handling. Its glossy screen finish significantly reduces the intensity of indirect reflections, like when glare from a ceiling light isn't directly facing the screen. It also does a fantastic job of reducing the intensity of direct reflections, like when a lamp is positioned in front of the screen. Unfortunately, reflections on the screen cause noticeable rainbow smearing, although not everyone will be bothered by this.
The TV has very good HDR native gradient handling. There's some noticeable banding in grays, but all other colors have minimal banding or no banding at all.
The TCL QM851G has great low-quality content smoothing. It does an excellent job at smoothing out artifacts in low bitrate content, but there is some loss of detail.
The TV does a good job with upscaling low-resolution content like DVDs, standard definition cable channels, and lower-resolution streams. Details are clear enough, but finer details and small hard-coded text are hard to make out.
Sharpness processing was calibrated with no over-sharpening for low-resolution content, with the following settings:
- Sharpness: 20
The TV uses a BGR (Blue-Green-Red) subpixel layout instead of the traditional RGB layout. For video or gaming content, this doesn't cause any issues, but for PC monitor use, it can be a problem as it impacts the text clarity, although not everyone will notice this.
The TCL QM851G has an excellent response time for minimal blur behind fast-moving objects, but it's slower when coming out of dark states, so there's some black smearing in dark scene transitions.
The TCL QM851G uses pulse width modulation (PWM) to dim its backlight, which introduces flicker that can bother people who are sensitive to it. Fortunately, it flickers at an incredibly fast 30,000Hz in all picture modes and at all brightness levels, so it's not noticeable.
The TCL QM851G has an optional backlight strobing feature, commonly known as black frame insertion. This feature is meant to reduce persistence blur and improve the appearance of motion. It works well at both 60Hz and 120Hz, with only some very minor image duplication. Note that enabling this feature reduces the panel's overall brightness.
This TV has an optional motion interpolation feature to improve the clarity of motion, but it doesn't work very well. Even slower-moving scenes have some noticeable artifacts present. It really struggles with faster-moving scenes, and there are distracting artifacts and haloing. Sometimes, the TV stops interpolating altogether, which is jarring.
Due to the TV's quick response time, there's some noticeable stutter when watching movies or TV shows, and it's most apparent in slow panning shots.
The TV automatically removes judder from all sources when watching movies or shows that are in 24p, even if they're in a 60Hz signal, like from a cable box.
The TV supports all three types of variable refresh rate (VRR) technology to reduce screen tearing. Its VRR range caps out at 144Hz or 240Hz, depending on the resolution. Unfortunately, it uses different overdrive settings under and above 65Hz. If you're gaming and your frame rate hovers between 60fps and 70fps, there's noticeable overshooting, which you can see here.
There's an inconsistent bug that prevents VRR from working at all. Despite the TV saying that VRR is on, there's noticeable screen-tearing. Power cycling it fixes the issue, and VRR works correctly.
This TV has incredibly low input lag when set to Game Mode with 'Game Master' turned on, which ensures a very responsive gaming experience with very little delay between your actions with your controller or mouse and the action on-screen. The input lag is 8ms when gaming in 1080p @ 240Hz.
Unfortunately, there's a reoccurring bug that prevents it from having the low input lag that it should while in Game Mode. To fix this, you have to power cycle the TV.
The TCL QM851G supports all common resolutions up to 4k @ 144Hz. HDMI 1 is the only port capable of 144Hz and 240Hz, while HDMI 2 can be used for gaming up to 120Hz. For 144Hz and 240Hz to work, you must enable 'High Frame Rate Mode.' Unfortunately, it doesn't support chroma 4:4:4 when set in Game Mode, and needs to be set to PC to display chroma 4:4:4. Unlike last year's TCL QM8/QM850G QLED, 1080p @ 240Hz with chroma 4:4:4 works without any issues as long as the TV is set to PC.
The TV is fully compatible with everything the PS5 offers, like 1440p @ 120Hz and 4k @ 120Hz, as well as HDMI Forum VRR. It also supports Auto Low Latency Mode, so you don't have to worry about manually switching to Game Mode to get the lowest input lag.
The TV is fully compatible with everything the Xbox Series X|S offers, including 1440p @ 120Hz, 4k @ 120Hz, HDMI Forum VRR, FreeSync Premium Pro, and Dolby Vision gaming. It also supports Auto Low Latency Mode, so you don't have to worry about manually switching to Game Mode to get the lowest input lag.
The TCL QM851G has HDMI 2.1 bandwidth on HDMI ports 1 and 2, but there are differences between them. HDMI 1 is the only port capable of 4k @ 144Hz and 1080p @ 240Hz, while HDMI 2 can be used for gaming up to 4k @ 120Hz. Fortunately, HDMI 4 is the eARC port, so you don't lose a high-bandwidth port when you plug in a soundbar. The TV supports all common HDR formats and has an ATSC 3.0 tuner, so you can watch over-the-air 4k content.
The TV supports eARC, which lets you pass high-quality, uncompressed audio to a compatible receiver or soundbar through an HDMI cable. It supports all major audio formats, so you don't have to worry about compatibility with external sources.
The TCL QM851G has a decent frequency response. Thanks to the built-in ONKYO subwoofer, it actually produces a bit of bass, but it's still not as good as the bass you get from a good soundbar. The sound profile is balanced enough that dialogue is easy to understand, but it does become more unbalanced at the TV's maximum volume.
The TV's distortion performance is just okay. At moderate volume levels, the distortion isn't too bad. At its maximum volume, the distortion is very noticeable, which is disappointing since it doesn't get very loud.
The TCL QM851G uses version 12 of the popular Google TV operating system. The interface is very smooth and easy to use.
Unfortunately, like almost all TVs on the market, the smart interface contains ads, and you can't disable them.
The TV has a fantastic selection of apps, so it's easy to find your favorite content. You can also cast content from your phone onto the TV or play videos directly from a USB stick.
The TV comes with the same remote as last year's TCL QM8/QM850G QLED. It has a motion-activated backlight, has buttons for popular streaming services, and you can use the built-in microphone to switch inputs, change apps, search within apps, and ask for the weather and time. Unfortunately, you can't change the settings on the TV using the voice controls.
