Gradient Banding Test
Detect color banding and posterization in smooth gradients
💡 Why This Test?
Gradient banding (or posterization) appears as visible "steps" or "bands" in what should be smooth color transitions. This occurs on displays with limited color depth - particularly 6-bit panels with FRC (Frame Rate Control) dithering trying to emulate 8-bit.
True 8-bit panels display 16.7 million colors smoothly. 6-bit+FRC panels (6-bit+2FRC) display only 262,144 native colors and use rapid flickering to simulate the rest, causing visible banding in gradients, especially in dark grays and subtle color transitions.
✅ What You'll Check:
- Visible steps/bands instead of smooth color transitions
- Color depth capability (6-bit vs 8-bit vs 10-bit)
- Posterization in all color channels (R, G, B, white)
- Gradient quality in different directions (horizontal, vertical, radial)
- Whether GPU color settings are limiting output
📖 How to Use This Test
- Start the fullscreen test for unobstructed view
- Navigate through 5 gradient patterns (horizontal, vertical, diagonal, radial, dual)
- Test all 7 colors: white (grayscale), red, green, blue, cyan, magenta, yellow
- Look for visible bands or steps in the gradient
- Count distinct bands you can see - fewer is better
- Note which colors show the most banding
- Check your GPU color depth settings (should be 8-bit or higher)
💡 Tip: Some banding is normal even on 8-bit panels. Severe banding (easily visible bands) suggests 6-bit+FRC. Check: 1) GPU set to "Full" RGB range, 2) Cable quality (use DisplayPort 1.2+ or HDMI 2.0+), 3) Windows color output set to 8-bit minimum.
Click to start fullscreen gradient testing. Use arrow keys to navigate patterns.
🌈 What You're Looking For
✅ Perfect Gradient
Smooth transition with no visible steps or bands
⚠️ Moderate Banding
Visible steps or bands instead of smooth gradient
❌ Severe Banding
Heavy posterization with obvious color steps
📋 Testing Guidelines
🎨 Multiple Colors
- • Test all color channels (R, G, B)
- • Grayscale gradients show banding most clearly
- • Some colors may show more banding than others
📐 Multiple Directions
- • Test horizontal, vertical, and diagonal
- • Radial gradients are good for corner testing
- • Banding may be direction-dependent
🔍 Common Causes
- • 6-bit panel with dithering (FRC)
- • 8-bit panel with poor processing
- • Graphics card settings (color depth)
- • Monitor calibration issues
Note: True 8-bit (or higher) panels should show smooth gradients. 6-bit+FRC panels may show slight banding in critical areas.
📋 How to Test
Start Fullscreen Test
Enter fullscreen mode for accurate gradient assessment without distractions.
Test Multiple Patterns
Navigate through 5 gradient patterns (horizontal, vertical, diagonal, radial, dual).
Test All Colors
Use color buttons to test white, red, green, blue, cyan, magenta, and yellow gradients.
Look for Steps
Identify visible bands or steps in the gradient. Should appear smooth, not posterized.
🔧 Common Issues & Solutions
🎨 "Visible color steps/bands in gradients" (6-bit + FRC panel)
What's happening: 6-bit + FRC (Frame Rate Control) panel using temporal dithering to simulate 8-bit color. True 6-bit displays 262,144 colors (64 × 64 × 64). 8-bit displays 16.7M colors (256 × 256 × 256). FRC rapidly alternates between two colors to create intermediate shades - causes visible posterization/banding in gradients. Common on budget gaming monitors: AOC 24G2, Gigabyte G24F, ViewSonic XG2405.
Detection and impact: Test gradients show distinct "steps" every 10-15% instead of smooth transition. Worse in 30-70% gray range where FRC temporal dithering most visible. Sky gradients in photos/games show banding. Professional monitors (BenQ SW270C, ASUS ProArt PA279CV) use true 8-bit or 10-bit panels. Check specs: "6-bit + Hi-FRC" or "6-bit + A-FRC" = not native 8-bit. TFTCentral reviews test bit depth objectively.
✅ Solution: Enable GPU dithering: NVIDIA Control Panel → Change Resolution → Output color depth → 8-bit (default). AMD Adrenalin → Display → Pixel Format → RGB 4:4:4 8-bit. Lower monitor overdrive (reduces FRC artifacts). Use DisplayPort over HDMI for better signal quality. Can't fully fix hardware limitation - some banding inherent to 6-bit+FRC. Upgrade to true 8-bit IPS/VA panel or 10-bit professional monitor (Dell UltraSharp UP2720Q, BenQ SW271C) for smooth gradients.
📏 "Vertical lines/striping in smooth gradients" (Poor dithering algorithm)
What's happening: Column-based FRC dithering creating vertical artifacts. Cheap 6-bit panels use simple checkerboard or line-based dithering patterns visible as repeating vertical stripes in gradients. Better panels (8-bit LG IPS, Samsung VA) use spatial + temporal dithering with pseudo-random patterns invisible to eye. Worse on grayscale gradients than color. Also caused by poor scaler chip processing (interpolation artifacts).
Cable and signal issues: HDMI 1.4 8-bit @ 60Hz has limited bandwidth - compression artifacts cause vertical banding. DisplayPort 1.2+ handles 8-bit or 10-bit without compression. Bad cables (cheap or damaged) introduce digital noise appearing as vertical lines. Non-native resolution scaling (1080p on 1440p monitor) creates interpolation banding. GPU color space mismatch: Limited RGB (16-235) vs Full RGB (0-255) causes posterization.
✅ Solution: Use DisplayPort 1.4 cable (not HDMI) for uncompressed 10-bit signal. Set GPU to Full RGB: NVIDIA → Change Resolution → Output dynamic range → Full. AMD → Display → Pixel Format → RGB 4:4:4 Full. Always use native resolution (no scaling). Upgrade cable to VESA-certified DP 1.4 (Club3D, Cable Matters). If vertical lines persist: Panel quality issue - some budget monitors (MSI Optix G241, Acer Nitro) have poor dithering. Upgrade to better panel technology.
✨ "Gradients shimmer/crawl when looking at them" (FRC temporal artifacts)
What's happening: Frame Rate Control rapidly alternates between two color values at 30-120Hz creating visible "crawling" or "shimmering" effect in gradients. More noticeable in peripheral vision or when scrolling. Sensitive individuals see FRC flickering even at 120Hz. Worse at lower refresh rates (60Hz FRC more visible than 144Hz). Some 6-bit+FRC panels (cheap TN, budget VA) have aggressive FRC causing eye strain.
Overdrive interference: Aggressive overdrive settings (Extreme, Ultra Fast) interact with FRC dithering causing additional temporal artifacts. Overdrive voltages + FRC temporal patterns = visible "noise" in midtones. VA panels worse than IPS - slower pixel response (8-15ms) conflicts with FRC timing. Gaming at variable framerates (G-Sync/FreeSync 40-144Hz) causes FRC rate mismatch - banding severity changes with FPS.
✅ Solution: Lower overdrive to "Normal" or "Medium" (not Extreme). Increase refresh rate if possible - 144Hz reduces FRC visibility vs 60Hz. Avoid gray/gradient-heavy content if sensitive. Use higher brightness (reduces FRC visibility, but increases eye strain trade-off). Can't disable FRC on 6-bit panels - hardware limitation. Long-term solution: Upgrade to true 8-bit panel (most IPS/VA gaming monitors $300+) or 10-bit professional display. OLED monitors (LG 27GR95QE) have perfect per-pixel color with zero dithering.
🔌 "8-bit monitor still shows banding" (Cable/GPU bit depth bottleneck)
What's happening: GPU outputting 6-bit or 8-bit signal despite monitor being 10-bit capable. HDMI 1.4 limits: 8-bit @ 60Hz (1080p/1440p), 6-bit @ 60Hz (4K). HDMI 2.0: 8-bit @ 144Hz (1440p), 8-bit @ 60Hz (4K HDR). DisplayPort 1.2: 8-bit @ 165Hz (1440p), 10-bit @ 60Hz (4K). DP 1.4: 10-bit @ 120Hz (4K), 8-bit @ 240Hz (1440p). Older GPUs (GTX 900 series) limited to 8-bit even with DP.
Color space and format: GPU set to YCbCr 4:2:0 or 4:2:2 (compressed chroma) instead of RGB 4:4:4 (full color). YCbCr causes color banding in gradients. Limited RGB (16-235 range, TV standard) vs Full RGB (0-255, PC standard) - Limited RGB crushes 20 color levels causing posterization. Windows HDR mode forcing 10-bit FP16 output but monitor only accepting 8-bit SDR. sRGB color space lock limiting 10-bit panel to 8-bit.
✅ Solution: Use DisplayPort 1.4 (not HDMI) for 10-bit color. NVIDIA: Control Panel → Change Resolution → Output color depth → 10-bit, Output color format → RGB. AMD: Display → Pixel Format → RGB 4:4:4 PC Standard Full, Color Depth → 10 bpc. Verify in OSD: Monitor should show "10-bit" or "1.07B colors". Check cable: VESA-certified DP 1.4 required for 10-bit HBR3. Windows Color Management: Disable "Use HDR" for SDR content (forces 8-bit).
🌈 "White gradients smooth but red/green/blue show banding" (RGB channel bit depth mismatch)
What's happening: Unequal bit depth across R, G, B channels. Some cheap panels: 6-bit red + 8-bit green + 6-bit blue = uneven gradient quality. Or FRC dithering optimized for green channel (human eye most sensitive 500-565nm) but worse on red/blue. Pentile subpixel layouts (RGBW with white subpixel) reduce effective color resolution. White gradients average all channels masking individual weaknesses.
Panel-specific color weaknesses: VA panels: Blue channel slower response causing temporal banding in blue gradients. TN panels: Poor viewing angles cause color shift in red/green gradients (looks different center vs edge). IPS panels: Generally balanced RGB but budget IPS may have 6-bit red+blue, 8-bit green. Test individual channels: Red gradient shows banding = red channel limited to 6-bit. Professional monitors have equal 10-bit per channel (30-bit total, "1.07B colors").
✅ Solution: Test all colors - if only one channel shows banding: GPU color calibration can't fix panel hardware limit. NVIDIA: Adjust "Digital Vibrance" per app may help. AMD: "Saturation" slider. Monitor OSD: Reduce oversaturated channel's gain (Color Temp User: R/G/B adjust). For professional work: Upgrade to true 8-bit or 10-bit panel with verified equal per-channel bit depth. TFTCentral reviews test this. EIZO ColorEdge, BenQ SW series guarantee 10-bit per channel. OLED perfect 10-bit RGB.