If you judged them purely based on how they’re spelled, QLED and OLED TV seem almost identical. Heck, even the Q and O look alike. But don’t be fooled: That one-letter difference makes all the difference in the world.
Let’s take an in-depth look at these two competing TV technologies. We’ll discuss where they come from, how they’re different from each other, and what each one does well (and not so well). We’ll also share which one we think most people will be happiest with. Spoiler: It’s the OLED TV, but there are caveats you need to be aware of.
Ready? Let’s begin.
What is QLED?
QLED stands for Quantum Light-Emitting Diode. In non-geek-speak, that means a QLED TV is just like a regular LED TV, except it uses tiny nanoparticles called quantum dots to super-charge its brightness and color. The technology was introduced by Sony in 2013, but shortly after that, Samsung began selling its QLED TVs and established a licensing partnership with other manufacturers, which is why you’ll now find QLED TVs from Sony, Vizio, Hisense, and TCL.
How do quantum dots work? Check out our deep-dive into the technology for all of the details.
As cool as quantum dots are, a QLED TV still produces light more or less the same way as a regular LED TV: by using a backlight made up of hundreds (or in some cases thousands) of LEDs, which sits behind a traditional LCD panel. It’s these LEDs that give LED (and QLED) TV its name.
Curiously, it’s this use of QLED as a marketing term that started a war between LG and Samsung in 2019. In a complaint to South Korea’s Fair Trade Commission (FTC), LG claimed that Samsung’s so-called QLED TVs aren’t real QLED TVs at all. That’s because according to LG, a true QLED TV would use quantum dot LEDs that emit their own light, and not the quantum-dot-film-over-an-LED-backlight that Samsung uses.
In a retaliatory move, Samsung told the FTC it was unhappy with all of the ads LG had been running, which attacked Samsung’s QLED TVs.
The FTC ultimately took Samsung’s side, but with a stipulation: It must make it clear in future advertisements that its QLED TVs use a backlight. Details, details.
The LCD panel — essentially millions of tiny shutters that open and close too quickly to see — in conjunction with color filters, creates the picture you see by letting just the right amount of light and color escape and reach your eyes. It’s a clever system, but it relies on a combination of dimming the LED backlights and using the shutters to block the remaining light to produce accurate on-screen blacks, and it doesn’t always succeed. We’ll discuss this more below.
What is OLED?
OLED stands for Organic Light-Emitting Diode. Somewhat surprisingly, the “Light Emitting-Diode” part of that name has nothing to do with an LED backlight as it does with QLED and LED TVs. Instead, it refers to the fact that every single pixel in an OLED TV is also a teeny, tiny LED light — but one that is incredibly thin and can produce both light and color in a single element. In other words, OLED TVs don’t need a backlight because each pixel produces its own light. If you want to impress your friends, you can use the industry terms for these kinds of displays: “emissive,” or “self-emissive.”
There are several advantages to this design, but most would agree that when it comes to OLED TVs, the biggest advantage is the superb black level that can be achieved. Unlike a QLED or LED TV that must dim its backlight and block what remains for dark scenes, an OLED TV simply turns off the pixel. When the pixel is off, it emits no light and no color, making it as dark as when the TV itself is turned off. With no separate backlight, it’s also a lot easier to make an OLED screen flexible, which is why OLED pioneer LG has developed several OLED TVs that roll up (or down) to disappear entirely.
Only one company currently makes OLED TV panels: LG Display. It sells those panels to its sister company, LG Electronics, which uses them to build some of the very best TVs you can buy. But LG Display also sells OLED panels to companies like Sony, Philips, and Panasonic, which is why you’ll see OLED TVs from these companies too. Even though the panels themselves are essentially identical, the image processing that Sony, LG, and others do is proprietary, so you’ll still see significant differences in picture quality from one OLED TV to another.
What about mini-LED?
In late 2019, TCL started selling the 8-Series — the very first QLED TVs powered by a mini-LED backlighting system. Mini-LEDs are tiny when compared to regular LEDs. This means that a QLED TV that could normally only accommodate hundreds of LEDs, can now accommodate tens of thousands of mini-LEDs. The result? Way more control over backlighting, leading to black levels that come far closer to OLED than any non-OLED display has ever achieved.
Mini-LED is still in its infancy, but if TCL and other companies continue to improve it (which they no doubt will) the technology could greatly improve QLED picture quality with pricing that should be considerably less than OLED.
And let’s not forget about micro-LED. Conceptually similar to mini-LED tech, micro-LEDs are even smaller than their mini brethren. Samsung made big waves at CES this year with the announcement of The Wall, a nearly bezel-free micro-LED display available in multiple (gargantuan) sizes. While most of us may be hard-pressed to fit a 150-inch TV in our living rooms, it never hurts to try.
QLED vs. OLED
Now that you know what all those letters stand for, and what they mean in terms of display technology, let’s compare QLED to OLED in the categories that matter most when buying a TV: Brightness, contrast, viewing angles and other notable performance considerations, like response time and lifespan — all important factors when you’re shelling out up to $6,000 for a top-of-the-line TV.
Black levels and contrast
Contrast is the difference between the darkest part of an image and the brightest part. If a TV can deliver a truly black dark portion, it doesn’t have to make the bright parts quite as bright to achieve good levels of contrast. That’s why, when it comes to black levels, OLED reigns as the undisputed champion — because of its ability to go completely black when it needs to.
QLED TVs (ahem) by contrast are forced to dim their LED backlights and block the remaining light, something that is very hard to do perfectly. It can trigger something called “light bleed,” as the light spills onto what’s supposed to be a black section of the screen.
But is it noticeable? Definitely. If you’re watching an intense action movie and two characters are running through a parking lot at night, for example, you may notice a slight glow on parts of the scene that are supposed to be pitch black, or in the letterbox bars at the top and bottom of the screen while watching a movie that uses a wider-than-16:9 aspect ratio.
As we highlighted earlier, mini-LED backlights are one way QLED TV makers are trying to improve this situation. It has real potential, but we’re not quite ready to declare it an OLED-killer.
For now, OLED comes out on top. If a pixel isn’t getting electricity, it doesn’t produce any light and therefore stays totally black.
QLED TVs have a considerable advantage when it comes to brightness. Because they use separate backlights (instead of relying on each pixel to create its own light) these LED backlights can be made incredibly, achingly bright. Add a quantum dot’s ability to maximize that light by producing brighter hues in the color spectrum without losing saturation and you’ve got a display that is more than bright enough to be seen clearly in even the most brightly lit rooms.
OLED panels can’t compete on a pure brightness basis. Their light-emitting individual pixels simply can’t produce the same amount of light. In a darkened room, this isn’t a problem. In fact, we’d argue it’s preferable because OLED can achieve the same contrast with less brightness, making dark-room viewing a less retina-searing experience. But in well-lit environments, or where lots of daylight streams in through windows, QLED TVs are more visible — especially if you’re playing HDR content under these conditions.
OLED panels have become brighter over the years, but they still can’t match QLED TVs.
OLED once blew all the competition out of the water in this section, but the use of quantum dots in QLED TVs have allowed it to inch forward in terms of color accuracy, color brightness, and color volume, according to Samsung, which claims that a wider range of better-saturated colors at extreme brightness levels are an advantage.
While there’s no denying the fact that QLEDs deliver fantastic colors, we have yet to witness better-saturated colors at high brightness levels deliver a real advantage in normal viewing situations — so we’re going to declare it a draw for now. We’ll need to see some tangible evidence to declare QLED a winner.
Response time, input lag, and refresh rate
Response time refers to the time it takes for a pixel to switch from one state to another. The faster the response time, the crisper the image, especially during fast-action scenes. Though there is likely a speed of response time beyond which the human eye is incapable of telling a difference, we know from standardized measurements that OLED TVs are way faster — orders of magnitude faster than QLED TVs.
Typical QLED response times vary between 2 and 8 milliseconds, which sounds pretty good until you realize that OLED’s response time is about 0.1 millisecond. Yup, it’s no contest.
Input lag, on the other hand, refers to the delay between taking an action (like pressing a button on a game controller) and seeing the result of that action on-screen. As such, input lag is really only a concern for gamers — it doesn’t have a noticeable effect on passive viewing of content at all.
Moreover, the amount of input lag you experience has little to do with one display technology over another, but more to do with how much image processing is happening on your TV behind the scenes. Both QLED and OLED TVs can achieve very low levels of input lag if you turn off all extra video processing or simply use the TV’s Game Mode, which effectively does the same thing.
Refresh rate is another category that will inherently matter more to gamers than casual viewers. The refresh rate is the number of times per second the TV updates what it’s showing on-screen. It’s closely related to frame rate, which is the number of times per second your TV show, movie, or video game sends a new update to the TV.
As long as these two rates are close multiples of each other e.g. a frame rate of 30 FPS and a refresh rate of double that (60 Hz), you’ll never notice a problem. And since regular TV content like movies and TV shows are always delivered at consistent frame rates, this is hardly ever a concern.
But some games running on consoles or PCs will change their frame rate from one scene to another. To keep everything looking as it should, TVs need a feature called VRR or Variable Refresh Rate. This lets your TV alter its native refresh rate to match these changes in frame rate. If your TV doesn’t support VRR, it can cause some unwanted side-effects like screen-tearing when used with the kinds of games that require VRR.
You can find VRR models in both OLED and QLED TVs, and 2020 will see many more come to market. But for now, only LG’s OLED TVs offer G-Sync support — a proprietary version of VRR created by Nvidia. If you’re a PC gamer who wants a big-screen gaming experience, this is a strong reason to look at LG’s latest OLED TVs.
Given OLED’s unbeatable superiority in response time and refresh rate, it owns this category.
With QLED screens, the best viewing angle is dead center, and the picture quality diminishes in brightness, color, and contrast the further you move side to side, or up and down. While the severity differs between models, it’s always noticeable — despite TV makers’ best efforts to eliminate the issue.
OLED screens, by comparison, can be viewed with no luminance degradation even at drastic viewing angles — up to 84 degrees. Some QLED TVs have improved in terms of viewing angle, with anti-reflective layers helping, but OLED maintains a clear advantage. So if you like to arrange family screenings for your favorite movies, and want to make sure there isn’t a bad seat in the house, an OLED TV is best for you.
OLEDs have come a long way. When the tech was still nascent, OLED screens maxed out at 55 inches. Today, screen sizes as large as 88 inches are possible, but only at great expense — the $30,000 price puts it out of reach for almost everyone. QLED technology is easier and less expensive to produce at larger sizes. Samsung’s 85-inch Q900TS 8K QLED TV is only $8,000, while its largest consumer model currently measures 98 inches.
LG says you would have to watch its OLED TVs five hours per day for 54 years before they fell to 50% brightness. Whether that’s true remains to be seen, as OLED TVs have only been out in the wild since 2013. QLED is even newer, but its source of backlighting — the LED — has a long and proven track record. For that reason and that reason only, we’ll award this category to QLED.
Winner (for now): QLED
Both QLED and OLED TVs can occasionally exhibit something called image retention. This is when a TV temporarily continues to display part of an image after the original has disappeared. It usually presents itself as a kind of shadow — that is, when it presents itself at all.
When image retention does occur, it’s usually the result of having the same visual element on-screen for long periods of time. Network logos in the corner of the screen have been known to cause it, as can video games that present the same interface elements throughout gameplay.
Image retention typically goes away on its own once you switch to some other kind of content that doesn’t show the problematic on-screen elements.
Because of their self-emissive nature, OLED TVs are also susceptible to the much rarer permanent version of image retention, which is known as “burn-in.” Burn-in is caused when one or more OLED pixels have their normal brightness permanently diminished to a lower state. The only fix for this is to lower all of the rest of the pixels to the same state, but that’s hardly a good solution.
For an absolute guarantee that you won’t experience burn-in, your best bet is QLED TV.
LG, as the biggest maker of OLED TVs, acknowledges the potential for image retention within its user manuals for its OLED TVs but says that under normal viewing conditions it shouldn’t happen.
So what constitutes “normal” viewing conditions? Well for one thing, keeping your TV on the same channel for 10 hours a day, two months in a row, is apparently not normal. One of our readers did this by watching MSNBC on his LG C8 OLED TV, which created what he claims is a burn-in shadow of a portion of the MSNBC peacock logo and a portion of the “Live” graphic that often accompanies it in the bottom right corner of the screen.
Should this scare you away from buying an OLED TV? Absolutely not. But if you’re picking a TV for use as a commercial display in a store, or perhaps in a waiting room, or if you think you’ll use it to play the same video game exclusively for months at a time, it’s definitely something to be aware of.
For an absolute guarantee that you won’t experience burn-in, your best bet is QLED TV.
As you’re now very much aware, OLED panels don’t require a super-bright backlight. Those backlights consume a fair amount of power, which means OLED TVs are inherently more energy-efficient. They also emit less heat than QLED TVs.
In today’s viewing age, it’s possible to spend hours staring at TV screens with few breaks in between. Eye fatigue is a real symptom of the act, and it’s usually caused by excessive blue light production. LCD-based sets tend to show more intense blue light than anything, and this is true even in scenes that don’t feature gobs of the shade. Go too far, and your irritable eyes could eventually lead to sleeplessness, which itself can contribute to a whole range of health problems. That’s why some OLED makers — most notably LG — are now seeking Ocular Guard certification for their panels.
Created by German safety testing firm TÜV Rheinland and previously marketed under the less-exciting “Eye Comfort Display” moniker, Ocular Guard certification tests a range of elements in TV panels to determine whether they’re too harsh on the eyes.
In theory, OLED TVs should offer better overall eye comfort than QLED and any other LCD-based screen, because OLED produces significantly less blue light than LED-backlit QLED TVs. It’s nothing a special pair of glasses can’t handle, but if you want to ensure you have the safest viewing experience possible that doesn’t require purchasing new glasses, OLED is your champ.
Once upon a time, this category would be handily won by QLED TVs, but OLED TVs have come down in cost, and since we’re talking all-premium here, comparable QLED TVs cost about the same (or more, depending on the size). 2020 is already shaping up to be a big year for TVs, especially for the U.S. market. Companies like Vizio and Philips are now offering OLED options at unbeatable prices, which should put more pressure on lowering cost for other brands. At the same time, TCL’s mini-LED QLED TVs will push from the opposite direction — improving the performance you can expect from less-expensive displays.
If you’re shopping around and see QLED TVs for cheap — and some of them are incredibly affordable — keep in mind that unlike OLED TV, there is a big range in picture quality with QLED TVs because there are far more variables in their design, picture processing, and build. Only the very top-of-the-line QLED TVs are equivalent to OLED in picture quality.
Both of these technologies are impressive in their own ways, but we’re here to pick a winner, and for the moment, it’s OLED. With better performance in the categories that most people will notice while watching TV shows and movies, it’s the best picture quality you can buy.
QLED comes out on top on paper, delivering a higher brightness, longer lifespan, larger screen sizes, and lower price tags. OLED, on the other hand, has a better viewing angle, deeper black levels, uses less power, and might be better for your health. Both are fantastic, though, so choosing between them is subjective; QLED is the better all-rounder, but OLED excels when you can control your room’s lighting.
The fact is, you can’t go wrong with either. That is, of course, until the next generation of display technology comes along. Mini-LED technology, for instance, is looking like a promising way for QLED TVs to deliver better black levels.
Samsung is also working on embedding quantum dot tech into OLED panels to create a new kind of TV: QD-OLED, which might create a TV with the best of both worlds. But since that’s likely a few years away still, we’ll have to wait and see. What we do know is that the company is serious, as it doubled down on its plans with an $11 billion investment. We’ll be watching developments closely to see how this technology evolves.