LED vs. LCD TVs explained: What’s the difference?

Confused about LED vs. LCD TVs? Here's everything you need to know

led vs lcd tvs samsung qled floor stand

Creating or upgrading a home theater setup can involve a lot of different things, but it often comes down to one major question: What kind of TV should you get? Flashy TVs like OLED models from LG or Sony or Samsung’s QLED TVs might get a lot of press, but when it comes to many of us, budget constraints limit our options, and we’ll find two terms coming up again and again: LED and LCD.

But what’s the difference? It’s a question we hear a lot from budding home theater shoppers, but shouldn’t. Blame the acronyms. Here’s the quick answer: An LED TV is an LCD TV, but how the two came to be confused with each other might come as a surprise.

An LED TV is an LCD TV

Despite having a different acronym, an LED TV is just a specific type of LCD TV. The proper name would actually be “LED-backlit LCD TV,” but that’s too much of a mouthful for everyday conversation, so people generally just refer to them as LED TVs.

Both types of TV make use of a liquid crystal display (LCD) panel to control where light is displayed on your screen. These panels are typically composed of two sheets of polarizing material with a liquid crystal solution between them, so when an electric current passes through the liquid, it causes the crystals to align so that light can (or can’t) pass through. Think of each crystal as a shutter, either allowing light to pass through or blocking it out.

Now, since both LED and LCD TVs use LCD technology, you’re probably wondering what the difference is. Actually, it’s about what the difference was. The LCD TVs you think of now no longer exist. Here’s why: Backlighting. Older LCD TVs used cold cathode fluorescent lamps (CCFLs) to provide backlighting, whereas LED TV’s used an array of smaller, more efficient light-emitting diodes (LEDs) to illuminate the screen, which gave them a few advantages. Now, all LCD TVs use LED lights and are colloquially considered LED TVs. Here’s how that works.

Backlighting

There are three different forms of illumination that have been used in LCD TVs: CCFL backlighting, full-array LED backlighting and LED edge lighting. Each of these illumination technologies is different from one another in important ways, and each has pros and cons. Let’s dig into each.

CCFL Backlighting

CCFL backlighting is an older form of technology that has mostly been abandoned, though some manufacturers do use CCFLs in lower tier LCDs since they’re cheaper to make. A series of CCFLs sit across the inside of the TV behind the LCD display. The lights illuminate the crystals fairly evenly, which means all regions of the picture will have similar brightness levels. This affects some aspects of picture quality, which we discuss on the next page. Since CCFLs are larger than LED arrays, CCFL LCDs tend to be thicker than their LCD counterparts. As this is an outdated technology, you won’t find many models using this style of illumination. A few tend to crop up here and there, but they’re almost always on the cheaper end of the spectrum.

Full-array backlighting

Full-array backlighting swaps the outdated CCFLs for LEDs. An array of LEDs spans the back of the LCD screen, with zones of LEDs can be lit or dimmed in a process called local dimming (we go deeper into how local dimming works on the next page). TVs using full-array LED backlighting make up a chunk the high-end LCD TV market, and with good reason — with more precise and even illumination, they can create better pictures than CCFLs LCD TV were ever able to achieve. Plus, they’re less of a power drain than CCFL LCDs were. Given these benefits, the shift to LEDs as industry standard made a lot of sense.

Edge lighting

Another form of LCD screen illumination is LED edge lighting. As the name implies, edge-lit TVs have LEDs along edges of a screen. Within this lighting type, there are a few different configurations, including LEDs along just the bottom; LEDs on the top and bottom; LEDs left and right; and LEDs along all four edges. These different configurations result in differences in picture quality, but the overall brightness capabilities still exceed what CCFL LEDs could achieve. While there are some drawbacks to edge lighting when compared to full-array or direct backlight, the upshot is edge lighting allows for manufacturers to make thinner TVs which cost less to manufacture.

To better close the local dimming quality gap between edge-lit TVs and full-array backlit TVs, manufacturers like Sony and Samsung have developed their own advanced forms of edge lighting. Sony’s technology is known as “Slim Backlight Master Drive,” while Samsung has “Infinite Array” employed in its line of QLED TVs. These keep the slim form factor achievable through edge-lit design but with local dimming quality more on par with full-array backlighting in these cases (though still not quite equal).

What is local dimming?

Local dimming is a feature of LED LCD TVs wherein the LED light source behind the LCD is dimmed and illuminated to match what the picture demands. LCDs can’t completely prevent light from passing through, though, even during dark scenes, so dimming the light source itself aids in creating deeper blacks and more impressive contrast in the picture. This is accomplished by selectively dimming the LEDs when that particular part of the picture — or region — is intended to be dark.

Local dimming helps LCD-based TVs more closely match the quality of Plasma (RIP) and OLED TVs, which feature better contrast levels by their nature — something CCFL LCDs couldn’t do. However, the quality of the local dimming effect varies depending on what type of backlighting your LCD uses and the quality of the processing. Here’s an overview of how effective local dimming is on each type of LCD TV.

Full-array and direct local backlighting

TVs with full-array backlighting have the most accurate local dimming and therefore tend to offer the best contrast. Since an array of LEDs spans the entire LCD screen, regions can be dimmed with more finesse than on edge-lit TVs, and brightness tends to be more uniform across the entire screen.

“Direct local dimming” is essentially the same thing as full-array dimming, just with fewer LEDs spread further apart in the array. It’s worth noting, however, that many manufacturers do not differentiate “direct local dimming” from full-array dimming as two separate forms of local dimming. We still feel it’s important to note the difference, however, as fewer, further-spaced LEDs will not have the same accuracy and consistency as full LED arrays.

Edge lighting

Edge lighting is a process by which light from LEDs positioned on the edge or edges of the screen is projected across the back of the LCD screen, as opposed to directly behind it. This works well enough but can result in very subtle blocks or bands of lighter pixels within or around areas that should be dark. Because of this, the local dimming of edge-lit TVs can sometimes result in some murkiness in dark areas when compared with full-array LED TVs. It should also be noted that not all LED edge-lit TVs offer dimming, which is why it is not uncommon to see glowing strips of light at the edges of a TV and slightly lower brightness toward the center of the screen.

CCFL Backlighting

Since CCFL backlit TVs do not use LEDs, models with this style of lighting do not have dimming abilities. Instead, the LCD panel of CCFL LCDs is constantly and evenly illuminated, which makes a noticeable difference in picture quality compared to LED LCDs. This is especially noticeable in scenes with high contrast, as the dark portions of the picture may appear too bright or washed out. When watching in a well-lit room it’s easier to ignore or miss the difference, but in a dark room, it will be, well, glaring.

OLED and QLED

As if it wasn’t already confusing enough, once you begin exploring the world of LED TVs, new acronyms crop up. The two you’ll most commonly find — and the two most important — are OLED and QLED.

Despite the similar sounding name, OLED TVs are a totally different category than LED TVs. We have an in-depth guide as to the differences between OLED and LED, but here’s a quick overview: Organic light-emitting diode (OLED) displays utilize a panel of pixel-sized organic compounds that respond to electricity, as opposed to LED bulbs. This allows for both deep contrast ratios and better per-pixel accuracy in the picture. OLED displays are often found on high-end TVs in place of LEDs, but that doesn’t mean that LEDs aren’t without their own premium technology either.

QLED is a premium tier of LED LCDs from Samsung and is therefore not a so-called emissive display technology like OLED or Plasma. However QLED TVs feature an updated illumination technology over regular LED LCDs in the form of Quantum Dot material (hence the “Q” in QLED), which ups overall efficiency. This translates to better, brighter grayscale and color, and enhances the HDR (High Dynamic Range). For a more detailed explanation of QLED, check out the above video, and be sure to read our list of the best TVs you can buy, which details the many features of QLED TVs. We also recommend checking out our OLED vs. QLED piece for a look at how these two premium-tier display technologies stack up, as well as our comparison of OLED and MicroLED for a look at a technology we’ll see coming to TVs in the near future.

Product Review

For picture quality on a budget, Vizio's new P-Series is absolutely unbeatable

Vizio’s P-Series TV line has always been the best among the brand’s long run of budget-friendly TVs, but this year’s model has really stepped up. While the competition is also improving, Vizio’s latest P-Series keeps the brand among…
Home Theater

The seven best TVs you can buy right now, from budget to big screen

Looking for a new television? In an oversaturated market, buying power is at an all-time high, but you'll need to cut through the rough to find a diamond. We're here to help with our picks for the best TVs of 2018.
Home Theater

MicroLED vs. OLED: Two hot TV technologies battle for your dollars

Samsung claims its new MicroLED TV tech offers all the benefits of OLED without the drawbacks. Join Digital Trends to take a close look to see if MicroLED TV lives up to the hype, and where it could go in the future.
Home Theater

TV calibration 101: Here's how to tune up the picture on your new TV

You’ve got your new TV out of the box, but now what? Our TV picture adjustment guide takes you through the simple steps to get the best picture from your brand-new TV so you can set it and forget it.
Home Theater

Lynxsonic’s 4:33 headphones offer premium features at a not-so-premium price

If you're looking for a set of wireless headphones that has a similar feature set to Bose's QuietComfort 35 but with a lower price, the Lynxsonic 4:33 is an intriguing new contender on Kickstarter.
Home Theater

Demystify home audio with our ultimate A/V receiver buying guide

Today's A/V receivers are packed with lots of advanced technology and just plain cool features. From understanding watt ratings to Wi-Fi, we explain how to buy one that will last you for years in our ultimate A/V receiver buying guide.
Movies & TV

The best shows on Netflix, from 'The Haunting of Hill House’ to ‘The Good Place’

Looking for a new show to binge? Lucky for you, we've curated a list of the best shows on Netflix, whether you're a fan of outlandish anime, dramatic period pieces, or shows that leave you questioning what lies beyond.
Home Theater

Google Chromecast and Chromecast Ultra: Everything you need to know

Google's Chromecast plugs into your TV's HDMI port, allowing you to stream content from your tablet, laptop, or smartphone directly to your TV. Here's what you need to know about all iterations, including the 4K-ready Chromecast Ultra.
Home Theater

The best noise-canceling headphones paint your music on a cleaner canvas

Drowning out the sound of babies, jet engines, and the outside world isn't as hard as it seems. Here are the best noise-canceling headphones, whether you're concerned with style, comfort, or sound.
Home Theater

The best movies on Netflix in October, from 'The Witch’ to ‘Black Panther’

Save yourself from hours wasted scrolling through Netflix's massive library by checking out our picks for the streamer's best movies available right now, whether you're into explosive action, subdued humor, or anything in between.
Movies & TV

Out of movies to binge? Our staff picks the best flicks on Hulu right now

From classics to blockbusters, Hulu offers some great films to its subscribers. Check out the best movies on Hulu, whether you're into charming adventure tales or gruesome horror stories.
Movies & TV

Stay inside this fall with the best shows on Hulu, including 'Castle Rock'

It's often overwhelming to navigate Hulu's robust library of TV shows. To help, we've put together a list of the best shows on Hulu, whether you're into frenetic cartoons, intelligent dramas, or anything in between.
Movies & TV

The best new movie trailers: ‘Curse of La Llorona,’ ‘Jonathan,’ and more

Everyone loves a good trailer, but keeping up with what's new isn't easy. To simplify things, we round up the best ones each week. On tap this week: New trailers for The Curse of La Llarona, The Kid Who Would Be King, and more.
Home Theater

Budget TVs are finally worth buying, and you can thank Roku

Not all that long ago, budget TVs were only worth looking at if, well, you were on a budget. Thanks to Roku, not only are budget TVs now a viable option for anyone, but they might even be a better buy than more expensive TVs.