OLED, QLED, Mini-LED: what actually changes on screen

One difference, and everything follows from it

Every TV you can buy today falls into one of two families, and the split is not about resolution, size or brand. It is about where the light comes from.

In an OLED panel, each pixel makes its own light. A pixel showing black is a pixel that is switched off — no light at all. In an LCD panel, a backlight shines from behind and a layer of liquid crystal blocks some of it to draw the picture. Blocking is never perfect, so black is really very dark grey with a little light leaking through.

QLED and Mini-LED are both LCDs. QLED adds a layer of quantum dots that makes the colours purer and lets the set run brighter. Mini-LED changes the backlight itself: instead of a few large lamps it uses hundreds or thousands of tiny LEDs, grouped into zones that can be dimmed separately, so dark parts of the picture get less light than bright parts.

What you actually see from the couch

Once you know where the light comes from, the rest of the spec sheet stops being a mystery.

• Dark scenes. OLED wins without a contest: a black sky is black. On an LCD the same sky is faintly lit, and on a Mini-LED set you may see a soft halo around bright objects — the subtitles, a streetlamp — because a whole dimming zone has to light up for a small bright thing.
• Bright rooms. LCDs, and especially Mini-LED ones, push more light. In a living room with big windows and no curtains that matters more than perfect black does.
• Off to the side. OLED keeps its colour and contrast when you are not sitting in front of it. Many LCDs wash out from an angle; some use a layer to widen the angle, and pay for it with weaker contrast.
• Static images. OLED can retain an image that sits in the same place for very long periods — a channel logo, a game HUD. Modern sets shift pixels and run cleaning cycles to limit it, but the risk is not zero, and it is higher if you use the TV as a monitor all day.

There is no winner in the abstract. There is a winner for your room: a dark room rewards OLED, a bright room rewards a good Mini-LED.

The numbers on the box

Some of the figures printed on the box describe the panel. Others describe the marketing department. The difference is worth knowing before you compare two prices.

• Refresh rate. The real one is the panel’s own, usually 60, 120 or 144 Hz. It matters for sports and for games. Numbers with invented names — motion rate, clear motion index — are not refresh rates and cannot be compared between brands.
• HDR. HDR10 is the baseline and everything supports it. Dolby Vision and HDR10+ carry extra scene-by-scene information, and which one a set supports depends on the brand, not on the panel.
• Contrast ratio. On an LCD spec sheet this number is close to meaningless, because it is measured in conditions you will never reproduce. Number of dimming zones tells you much more.
• Nits. A peak brightness figure is usually measured on a small patch of the screen for a short moment, not on the whole picture. Useful to compare roughly, useless to trust precisely.

Side by side

And then there is the price

TVs are the category where crossed-out prices do the most damage, because the numbers are big enough that a fake 30% looks like a real saving. Three checks, and they take under a minute.

• Ask what the discount is measured against. A percentage off a list price nobody has paid in two years is not a discount. A percentage off what the set actually sold for last month is.
• Look at the reference the store itself shows, and use that one. In the US, Amazon often shows a typical price — the median of what customers actually paid over the previous 90 days. In the EU, the law requires the lowest price of the previous 30 days. They are different numbers and they answer different questions.
• Check the model number, not the model name. Manufacturers sell near-identical sets under slightly different codes to different retailers, and the one on offer is sometimes the cheaper build.

This is the same check we run before we publish anything. If a price does not survive it, the deal does not go out — which is why some days we publish less.