Gradient & Banding Test
Go fullscreen and step through gray ramps, RGB channels and near-black gradients: a smooth ramp shows no seam; visible vertical bars or step lines mean banding.
Step through gray, RGB and near-black ramps: a smooth gradient shows no seams; visible bars or steps are banding.
What to look for
- Horizontal and vertical gray ramps should flow perfectly smooth — vertical bars or visible bands mean contouring from panel bit depth, dithering or output settings.
- Check each RGB channel separately: banding that appears on only one channel points to color-management or cable issues rather than the panel itself.
- The near-black ramp (0–10%) is the harshest: OLEDs may show mura/color patches, LCDs may crush it flat — judge at your usual brightness.
- Before blaming the panel, rule out the chain: try another cable, set the GPU to RGB full range, and disable night mode / color filters.
Frequently asked questions
What is banding?
A smooth gradient split into visible steps. Causes include a 6-bit physical panel, poor dithering, insufficient GPU output depth, or compressed source material. True 8/10-bit panels show no contouring at normal distance.
Does visible banding mean the panel is defective?
Not necessarily. Try another cable (HDMI/DP), set the GPU output to RGB 4:4:4 full range, disable night mode and color filters, then retest. Banding inside a low-bitrate video is a source problem, not a screen problem.
Why a near-black ramp?
The 0–10% range exposes the most: OLEDs often show mura and color shifts at low gray, while LCDs can crush the whole range into flat black. Check it at your normal brightness level.
Is this worth running on a phone?
Yes — AMOLED panels especially: many compress near-black gradation at low brightness, which is exactly the blocky look in dark-mode video playback.