HDMI Signal & Chroma Processing Tests
Twenty-six test videos for isolating signal-chain problems - full vs. limited RGB range, chroma subsampling (4:4:4/4:2:2/4:2:0), BT.601 vs BT.709 colour matrix, and bit-depth/FRC dithering - across HDMI sources, cables, switches and displays.
What these files actually are
Download the file rather than watching on YouTube for anything below-black or range-sensitive: YouTube re-encodes and can normalise signal levels, which erases exactly the artefact you're trying to test for. Free download, no watermark, no attribution required, each with a SHA-256 hash and VirusTotal link.
Online full-screen test
Run the test right in your browser, no download needed. Press Start, then click or use the arrow keys to switch patterns. To test a TV or projector without a browser, use the video files further down.
Click / → / Space: next · ←: previous · A: auto-play · Esc: exit
How to run the test
- Clean the screen and set the display to its native resolution with 100% scaling.
- Press Start (or pick a pattern below). The test fills the whole screen; the controls hide after a moment.
- Look over the whole screen on every pattern, from normal viewing distance and then up close.
- Press Esc to leave. Note where any defect is and photograph it on the pattern that shows it best, e.g. for a warranty claim.
Test patterns and what to look for
- Text clarity
- Small text should be crisp, without coloured fringes, on both white and black. Adjust ClearType or font smoothing and the display's sharpness.
- Sharpness
- 1-pixel lines and checkerboards should look crisp and even. Moiré, colour fringes or blur mean the image is scaled or sharpening is too high. Use native resolution, 100% scaling, and on TVs 'Just Scan' or 'Screen Fit'.
- Color bars
- 75% colour bars for checking colour order, saturation and tint on TVs and projectors.
- Gradient
- Gray and red, green and blue ramps should be smooth. Visible steps (banding) point to a low bit depth, over-processing or a wrong colour profile.
- Black level
- Squares 1–19 on black. You should be able to tell at least the squares from 3 or 4 upward apart from the background. If they merge into black, shadows are crushed: raise brightness or black level, or check the RGB range (full vs limited).
- White level
- Squares 236–254 on white. If the brightest squares merge into white, highlights are clipped: lower contrast.
Common use cases
HDMI signal chain troubleshooting
Isolate whether a color or black-level problem comes from the source, the cable/switch, or the display.
Console and PC range matching
Confirm your device's RGB/YCbCr range setting matches what your display expects.
PLUGE Black Level Test – Below Black and Above Black
YouTube re-encodes video and may normalize levels - the DOWNLOADED file carries the exact code values and range flags; use it for the real measurement. Set brightness so the Y=4 bar disappears but Y=20 stays just visible.
HDMI RGB Full vs Limited Range Test
YouTube re-encodes video and may normalize levels - the DOWNLOADED file carries the exact code values and range flags; use it for the real measurement. Play BOTH downloaded files: if blacks look gray or shadows crush in one of them, your chain misreads the range flag.
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Downloadfull-rangeMP4 · 796 KB
HDMI Black Level Mismatch Test
YouTube re-encodes video and may normalize levels - the DOWNLOADED file carries the exact code values and range flags; use it for the real measurement. Match your TV's 'HDMI Black Level / Full-Limited' setting to your source - the patches show a mismatch instantly.
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Downloadfull-rangeMP4 · 797 KB
Console RGB Range Test – Full or Limited
YouTube re-encodes video and may normalize levels - the DOWNLOADED file carries the exact code values and range flags; use it for the real measurement. PS/Xbox RGB range setting: test with both files; 'Limited' is correct for most TVs.
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Downloadfull-rangeMP4 · 786 KB
HDMI Full RGB Test Pattern
YouTube re-encodes video and may normalize levels - the DOWNLOADED file carries the exact code values and range flags; use it for the real measurement. For PC monitors over HDMI: full RGB should show code 0-15 steps as distinct near-blacks.
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Downloadfull-rangeMP4 · 785 KB
RGB Channel Clipping Test – Red Green Blue
YouTube re-encodes video and may normalize levels - the DOWNLOADED file carries the exact code values and range flags; use it for the real measurement. Each ramp must reach its end without flattening - a flattened end means that channel clips.
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Downloadfull-rangeMP4 · 740 KB
YCbCr Luma and Chroma Clipping Test
YouTube re-encodes video and may normalize levels - the DOWNLOADED file carries the exact code values and range flags; use it for the real measurement. Luma and chroma clip independently - check all three ramps.
Chroma Range Error Test
YouTube re-encodes video and may normalize levels - the DOWNLOADED file carries the exact code values and range flags; use it for the real measurement. Saturation ramps out to the legal chroma limits - early flattening = chroma range error.
BT.601 vs BT.709 Color Matrix Test
YouTube re-encodes video and may normalize levels - the DOWNLOADED file carries the exact code values and range flags; use it for the real measurement. File is tagged BT.709: the RIGHT half must look correct. If the left half looks right instead, your chain decodes with the wrong matrix.
Chroma Alignment Test – Luma and Color Channels
Red and blue lines sit exactly 4px from their white luma markers - any drift is chroma misalignment.
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Download444MP4 · 678 KB
Horizontal Chroma Alignment Test
Vertical line set for horizontal chroma shift.
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Download444MP4 · 593 KB
Vertical Chroma Alignment Test
Horizontal line set for vertical chroma shift.
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Download444MP4 · 579 KB
Chroma Multiburst Resolution Test
Compare where luma bursts and chroma bursts stop resolving - the gap is your chroma resolution loss.
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Download444MP4 · 794 KB
Chroma Zone Plate Test
Aliasing rings and smears in the chroma plate (right) expose upsampling and scaling errors.
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Download444MP4 · 21 MB
Chroma Bleeding and Color Fringing Test
Color haze spilling past the sharp block edges is chroma bleed.
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Download444MP4 · 634 KB
4:4:4 vs 4:2:2 vs 4:2:0 Comparison
The three subsampling levels side by side - the middle and right panels show what your chain may be doing to the left one.
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Download444MP4 · 3.6 MB
RGB vs YCbCr Text Test
RGB output keeps text like the left panel; YCbCr 4:2:0 output looks like the right one.
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Download444MP4 · 3.6 MB
TV PC Mode Chroma Test
Enable PC/Game mode with 4:4:4 support and compare - without it, TV processing gives you the right-hand panel.
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Download444MP4 · 3.6 MB
Chroma Upsampling Error Test 24p
Fine vertical chroma detail at 24p - streaky color rows during playback are the chroma upsampling error.
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Download444MP4 · 484 KB
Chroma Upsampling Error Test 30p
The same chroma detail at 30p - some chains only mishandle one cadence.
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Download444MP4 · 587 KB
Fine Gradient Quantization Test
A 0-40 gradient over the full width: visible steps = quantization, shimmer = dithering (FRC).
Low Brightness Dithering Noise Test
At minimum brightness, film the flat patches with your phone at several shutter speeds - crawling noise is temporal dithering. Do not judge panel bit depth from the YouTube stream.
LCD Temporal Dithering Test
Results depend on your camera, shutter speed, room lighting, mains frequency and brightness setting - do not draw hard conclusions from one video. The gradient alternates by one quantization step per frame (simulated FRC). Film it at several shutter speeds; do not judge panel bit depth by eye or from the YouTube stream.
FRC Flicker Camera Test
Results depend on your camera, shutter speed, room lighting, mains frequency and brightness setting - do not draw hard conclusions from one video. A dark LSB-dithered gradient - crawling noise on camera indicates temporal dithering.
6-Bit + FRC vs True 8-Bit Test
Results depend on your camera, shutter speed, room lighting, mains frequency and brightness setting - do not draw hard conclusions from one video. Banded vs FRC-dithered vs smooth gradient. A 6-bit+FRC panel renders the middle band with visible crawling noise.
8-Bit + FRC vs True 10-Bit Test
Results depend on your camera, shutter speed, room lighting, mains frequency and brightness setting - do not draw hard conclusions from one video. Finer steps for the 8-bit vs 10-bit case - the real 10-bit test file is in the HDR download set.
Frequently asked questions
- Why does this need the downloaded file, not just YouTube?
- YouTube re-encodes and can normalize signal levels, so below-black and range-sensitive patterns are only accurate in the original downloaded file.
- What's a range mismatch look like?
- Crushed black detail, clipped whites, or a washed-out/over-contrasted image are typical signs of a full vs. limited range mismatch.
- Which test should I start with?
- HDMI RGB Full vs Limited Range Test catches the most common signal-chain mismatch; move to the chroma-subsampling tests only if colour on fine detail or text still looks off afterwards.
More test categories
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