Is Your TV Blurry? This One HDMI Setting Might Fix It

Have you ever tried connecting your computer to your TV, only to be treated to line after line of blurry text? How could this be happening, you wonder, especially since everything looks fine when you watch cable TV or stream Netflix? The likely culprit is something called chroma subsampling, a picture technology that compresses the amount of color information traveling between your HDMI cable and your TV.

Modern displays continue to see improvements in resolution, refresh rate, and other picture features, which require increased amounts of HDMI bandwidth. Chroma subsampling trades some of your source component's color fidelity, so your display can receive more luminance data — also referred to as luma. Without subsampling, we wouldn't be able to take full advantage of formats like HDR and 10-bit color depth. 

But if you're using your TV as a primary computer monitor and are cursed with blurry text, it's usually because chroma subsampling needs to be disabled. We're all about tips and tricks for optimizing TV image quality, and shutting off subsampling can work wonders. To do so, you'll need to manually enable chroma 4:4:4 support within your TV's picture settings. Look for something called "HDMI UHD Color" and turn it on for the HDMI port your PC is connected to. You'll also want to make sure you're using the "PC" picture preset.

You may have seen "chroma 4:4:4" tossed around in display discussions and it's worth understanding in the context of TV HDMI settings. Chroma 4:4:4 is a complete, uncompressed signal that doesn't sacrifice any amount of color fidelity. The first number refers to the size of the sample (or luma), while the other two numbers refer to the horizontal and vertical sampling of chroma.

Most AV components and streaming apps actually use chroma 4:2:0, which is a quarter the amount of color information as 4:4:4. If they didn't, popular streaming services like Netflix and HBO Max would be forced to push massive amounts of data, resulting in laggier performance for most households. But thanks to the higher pixel density of many modern displays, the color loss you experience with 4:2:0 — and even 4:2:2 subsampling — is less noticeable.

For those of us watching cable TV or enjoying DVD content, chroma subsampling is probably something you'll never have to worry about. Should you decide to use your living room TV as the main display for your PC, however, you may have to go digging around for the chroma 4:4:4 setting to eliminate font-based fuzziness. And while you're at it, you may want to sit down with a test image and give your smart TV the calibration it deserves.