Mini-LED TV: What It Is and How It Improves Samsung, TCL, Hisense, Roku TVs

TVs get a bit better every year, and many middle- to high-end TVs today use mini-LEDs. Mini-LED is an evolution of traditional LCD TV backlight tech that uses thousands of tiny light-emitting diodes to improve picture quality. Some of the best TVs CNET tested in 2023 use mini-LEDs, and major brands including Samsung, TCL, Hisense and Roku all introduced new mini-LED TVs at CES 2024.

Let's start with what makes mini-LED special. By using more, smaller LEDs to illuminate the screen, a TV can have finer control over its highlights and shadows, for potentially better contrast and image quality especially with HDR shows, movies and games. Mini-LED's main advantage over OLED, the best TV tech on the market, is that it can be more affordable, particularly in larger screen sizes. Mini-LED is an evolutionary technology, not a revolutionary one, and draws on existing LCD TV technology. In the mini-LED TVs we've tested so far, including the TCL QM8 and Hisense U8K, the picture quality improvements are the real deal, although not quite good enough to beat OLED. 

Now that just about every TV maker will sell a mini-LED TV of some kind in 2024, you're bound to hear a lot more about the technology. Here's how it works, and why it's so cool.

Mini-LED is not micro-LED

Before we get started, know that mini-LED and micro-LED are not the same thing. Micro-LED is a very high-end tech that's reserved for huge screens and rich people today -- like a 110-inch Samsung for the cool price of $156,000. A company called C Seed also released a $200,000 137-inch micro-LED TV, and the screen can be folded into a bench when not in use. 

Micro-LED displays use millions of LEDs, one for each pixel. Essentially, you're looking directly at the LEDs that are creating the picture. And while each individual micro-LED is tiny, the modular nature of micro-LED means it can get truly gigantic. Samsung also rolled out its first transparent micro-LED TV at CES 2024.

Mini-LED, on the other hand, is a much more mainstream technology, and is currently available in TVs as small as 55 inches and as affordable as $450. Mini-LEDs themselves are much larger than micro-LEDs. Just like the standard LEDs found in current TVs, they're used to power the backlight of the television. A liquid crystal layer, the LCD itself, modulates that light to create the image. (Micro-LED isn't LCD at all. It's a whole new TV technology that also happens to use LEDs.)

Here's how the two stack up against one another as well as standard LED, QLED and OLED.

Bright lights, big TV, better local dimming

To understand mini-LED, you need to understand standard LED, at least as far as your TV is concerned. Inside all modern LCD TVs (i.e. every TV that's not an OLED), there's anywhere between a few to a few hundred light-emitting diodes. These tiny devices emit light when you give them electricity and are being used everywhere in the modern world, from the flashlight on your phone to the taillights on your car. They range in size -- commonly they're around 1 millimeter, but can be smaller than 0.2 millimeter. In your TV, these LEDs are collectively referred to as the "backlight."

In some TVs the LEDs are on the edges, pointing inward. On others, the LEDs are behind the screen, pointing toward you. For improved image quality, particularly to appreciate high dynamic range, aka HDR, you need local dimming. This is where the TV dims the LEDs behind dark sections of the image to create a better contrast ratio between the bright parts of the image and the dark. For more on this, check out LED local dimming explained.

Watch this: Best TVs of CES 2024

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Ideally, you'd be able to dim each pixel enough to create a visually impressive contrast ratio. This is, for example, how OLED and micro-LED work. With LCD, though, it's much harder to do. The liquid crystal panel that creates the image only blocks the light created by the backlight. Not all the light can be blocked, so the image is grayer and has less "punch" than with OLED. 

Local dimming improves this issue, but it's not 1:1. There isn't one LED for each of the 8 million-plus pixels in a 4K TV. Instead there are thousands, if not hundreds of thousands of pixels for every LED (or more accurately, groups of LEDs called "zones"). There's a limit to how many LEDs you can squeeze onto the back panel of a TV before energy drain, heat production and cost become severely limiting factors. Enter mini-LED.

Going big with little LEDs

Although there's no accepted threshold, LEDs smaller than 0.2 millimeter tend to be called mini-LEDs. Not too small though: At around 0.01 millimeter, they're called micro-LEDs.

Generally speaking, when you make an LED smaller, it becomes dimmer. There's less material to create the light. You can offset this a bit by giving them more electricity ("driving" them harder), but there's a limit here, too, constrained by energy consumption, heat, longevity and practicality. No one is going to hook their TV up to a high-amp, home appliance-style outlet. 

As LED technology improves, they get more efficient. New tech, new manufacturing methods and other factors mean that the same amount of light is created using less energy, or more light using the same energy. New tech also allows for smaller LEDs.

One of the first mini-LED TVs available was TCL's 8-Series from 2019. It had over 25,000 mini-LEDs arrayed across the back of the TV. These were grouped into around 1,000 zones. Both of these numbers are significantly higher than what you'd find in a traditional LED TV, and newer, larger mini-LED TVs have even more zones. The 115-inch TCL TV announced at CES 2024, for example, has 20,000 local dimming zones, while the 110-inch Hisense has 40,000. 

Don't expect every mini-LED TV to have that many LEDs and dimming zones, of course. Lower-end models will have far fewer, but likely still more than regular LED TVs. For instance TCL's 65-inch 6-Series from 2022 has 240 zones -- more than many models at its price but clearly not at the same level as the older 8-Series. Recently TV makers like TCL have stopped disclosing mini-LED and zone counts for smaller TVs, instead only focusing on the largest, most impressive numbers.

If you were to take the LCD layer of the TV off, the mini-LEDs would create an image that looked like a low-resolution black-and-white internet video version of the show you were watching. (See the pairs of image comparisons above.) By being able to dim parts of the screen far more precisely, the overall apparent contrast ratio goes up. It's still not quite as good as being able to dim each pixel individually (like OLED and micro-LED), but it's far closer to that ideal than even the most elaborate full-array LED LCDs now. 

Having more zones is a big factor here, as it means improving two other aspects of the image. The most obvious is reducing the "blooming" typical of many local-dimming LCDs. Blooming is created because the local-dimming backlight is too coarse, creating light behind a part of the image that should be dark. 

Imagine a streetlight on an otherwise dark road. A local-dimming TV doesn't have the resolution in its backlight to only light up the pixels creating the street light, so it has to light up some of the surrounding night as well. Many LCD TVs have gotten pretty good at this, but not as good as something that can dim each pixel like OLED. With mini-LED, you might not be able to light up individual stars in a night scene, but the moon probably won't have a halo.

Because there's less of a chance of blooming, the LEDs can be driven harder without fear of artifacts. So there can be a greater on-screen contrast ratio in a wider variety of scenes. The bright parts of the image can be truly bright, the dark parts of the image can be at or near totally dark.

Samsung Neo QLED, LG QNED: What's in a name?

The overall name for the technology is mini-LED. That's what TCL, Sony and Hisense call it, while LG and Samsung, true to form, prefer to use their own names.

Samsung's is Neo QLED, building on the company's years of marketing QLED with quantum dots. LG's QNED, based on its Neo-LED technology, is a new addition to the bewildering world of TV acronyms and can also include mini-LEDs.

There are bound to be differences between how these companies implement mini-LED, most notably how many LEDs are on each size of TV. On top of that, how well these LEDs are addressed and other factors will determine how good they look compared to each other and to other TV technologies.

The dark night returns

Deep blacks and bright whites are the holy grail of TV image quality. Add in the color possible with quantum dots and you've got the makings of a fantastic-looking television. LCD is still the only cost-effective alternative, and while it has come a long way, it's an aging technology. Mini-LED is the latest solution keeping it in the game.

We'll continue comparing the best mini-LED-based TVs against OLED in the near term and, eventually, micro-LEDs as well.

As well as covering TV and other display tech, Geoff does photo tours of cool museums and locations around the world, including nuclear submarines, massive aircraft carriers, medieval castles, airplane graveyards and more. 

You can follow his exploits on Instagram and YouTube, and on his travel blog, BaldNomad. He also wrote a bestselling sci-fi novel about city-sized submarines, along with a sequel.