Chroma Subsampling
Chroma subsampling saves bandwidth by keeping full brightness detail but reducing color detail — the eye barely notices. 4:4:4 is full color (best for PC text), 4:2:2 halves horizontal color, and 4:2:0 halves color both ways (the norm for movies and TV). If colored text looks fuzzy, you're likely on 4:2:0 — switch to 4:4:4, which needs more bandwidth.
A pixel's value splits into luma (brightness) and chroma (color). Because human vision is much sharper for brightness than for color, video links can transmit color for fewer pixels and free up bandwidth with little visible effect — especially on photographic and video content.
4:4:4 vs 4:2:2 vs 4:2:0
| Format | Color resolution | Relative bandwidth | Best for |
|---|---|---|---|
| 4:4:4 | Full | Highest | PC desktop, text, sharp UI |
| 4:2:2 | Half (horizontal) | Medium | Pro video, some consoles |
| 4:2:0 | Quarter (horizontal & vertical) | Lowest | Movies, TV, streaming, Blu-ray |
Brightness detail is identical in all three — only the color resolution changes. That's why a movie at 4:2:0 looks perfect, but small red text on a black background can look fuzzy at 4:2:0 and crisp at 4:4:4.
Which should you use?
- PC monitor (text, desktop, coding): 4:4:4 (full RGB) for the sharpest text.
- Movies, TV, streaming: 4:2:0 is standard and looks identical for that content.
- Bandwidth-limited high-res modes: a device may drop to 4:2:2 or 4:2:0 to fit, e.g. 4K @ 60 Hz over HDMI 2.0 at higher color depth.
Chroma is one of the inputs to the bandwidth calculator — switching from 4:4:4 to 4:2:0 noticeably lowers the required data rate. If you can't get 4:4:4 at your resolution, you need more bandwidth: a higher-grade cable or interface.
Chroma subsampling: frequently asked questions
What is chroma subsampling?
Chroma subsampling saves bandwidth by sending full brightness (luma) detail but reduced color (chroma) detail, because human eyes are far more sensitive to brightness than to fine color. It is written as ratios: 4:4:4 (full color), 4:2:2 (half horizontal color), and 4:2:0 (quarter color).
What is the difference between 4:4:4, 4:2:2, and 4:2:0?
All three keep full brightness detail; they differ in color:
- 4:4:4 — full color resolution, highest bandwidth.
- 4:2:2 — half the horizontal color resolution.
- 4:2:0 — half horizontal and half vertical color, the least bandwidth.
Which chroma subsampling should I use?
For a PC monitor showing text and the desktop, use 4:4:4 so small colored text stays sharp. For movies, TV, and most video, 4:2:0 is the norm and looks identical for that material. Consoles often use 4:2:2 or 4:2:0 at high resolutions to fit the bandwidth.
Why does colored text look blurry or fuzzy on my TV/monitor?
It is usually 4:2:0 or 4:2:2 chroma subsampling softening the color edges of small text. Switch the source to 4:4:4 (full RGB). If 4:4:4 isn't available at your resolution and refresh rate, the link lacks the bandwidth — use a higher-grade cable, a better interface, or lower the refresh rate or color depth. The bandwidth calculator shows what fits.
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