What is color banding on a TV?
Color banding shows up as visible steps or stripes in what should be a smooth change of shade, most often in a sunset sky, a dim room, or a slow fade to black. Instead of a seamless gradient you see bands, like the lines on a contour map. Some of it is your TV, but a surprising amount is the video itself. Here is what causes it, and what actually helps.
What banding looks like
A smooth gradient, a clear sky fading from deep blue to pale, should blend one shade into the next with no visible edge. Banding is when those shades jump in steps instead, leaving faint stripes across the picture. Once you have noticed it you cannot unsee it. It shows up most in large areas of one slowly changing color: Skies, sunsets, shadows, spotlights, and the fades between scenes.
What causes it
Three things, and they stack. The biggest is usually the source: Streaming and broadcast compress video hard to save bandwidth, and smooth gradients are the first thing that compression throws away, so a lot of banding is baked into the stream before your TV ever sees it. The second is the panel's bit depth, how many shades it can show, which the next section covers. The third is the TV's own processing, which can add banding while stretching or sharpening the image. Because the source is so often the culprit, the same clip can band on one service and look clean on a better one.
8-bit vs 10-bit, and do you need it
Bit depth is how many shades of each color a screen can show. An 8-bit panel manages about 16 million colors; a 10-bit panel manages over a billion, which means far finer steps between shades and smoother gradients. 10-bit is part of what makes HDR look good, so for HDR it genuinely helps. But here is the honest part: If the banding is coming from a compressed stream, a 10-bit panel cannot put back detail that was thrown away at the source. It smooths what it is handed; it does not invent the missing shades. So 10-bit is worth having, but it is not a cure-all.
What actually helps
A few things, in order. Many TVs have a smoothing setting, often called Smooth Gradation or something similar, that blends the steps to hide them: Turn it on low, because a high setting softens real detail too. Then feed the TV a better source, since that matters most: The 4K tier of a service usually bands far less than its HD tier. And check the panel is not the weak link. Our Color Banding Test shows a clean set of gradients, so you can see how your screen handles them with the source taken out of the equation.
Questions people ask
What is color banding on a TV?
It is visible steps or stripes in what should be a smooth change of shade, most obvious in skies, sunsets and shadows. Instead of blending, the shades jump in bands. It is caused by a mix of video compression at the source, the panel's bit depth, and the TV's processing.
Will a 10-bit TV fix banding?
It helps, but it is not a cure. A 10-bit panel shows far finer steps between shades and is part of good HDR. But if the banding is baked into a compressed stream, a 10-bit panel cannot restore detail that was already thrown away. The source quality matters as much as the panel does.
Why do I see banding on Netflix but not on a Blu-ray?
Because a disc carries far more data than a stream. Streaming compresses gradients hard to save bandwidth, and that compression is where most banding comes from. The same scene from a Blu-ray, or from a higher streaming tier, has more information to work with and bands less.
To see how your own screen handles gradients, with the source taken out of the picture, run the Color Banding Test. For the bit-depth and HDR side of it, see what is HDR.