People buying a new or used monitor can use the labeled patches as a simple first look before making a decision. For a useful comparison, keep the room and display settings consistent, and note which setting you change between views.
How to use HDR Test
- Read the current browser dynamic-range and gamut reports shown on the page.
- Select Start Test to begin. The displayed pattern labels include “Pattern mode,” “SDR reference only,” “Nine patches,” and “Black to white · horizontal.”
- Use Previous and Next, or the Left and Right arrow keys, to move through patterns. Press Space for automatic mode; with reduced motion, progression stays manual.
- Select Fullscreen or press F to fill the display with the pattern. Press Escape to leave fullscreen. On a phone, the Exit button remains on screen; in fullscreen, tap the left or right half to move between patterns.
- Use Reset or press R to reset. Read patch values from left to right; for layouts with rows, continue from top to bottom. Legends stay outside fullscreen.
When to use it
- Checking a new monitor before the return window closes: Look for visible steps in the references and note anything that seems unusually indistinct.
- Considering a second-hand display: Scan the patterns across the screen as an initial visual check before buying.
- Comparing picture settings: View the same pattern before and after changing one setting to see whether the tonal appearance changes.
- Checking dark shades: The black patches help you see whether nearby dark tones appear distinguishable.
- Checking bright shades: Compare the white patches for visible differences between neighboring light tones.
- Reviewing browser capability reports: See the reported dynamic-range and gamut information beside the references, while treating it as a report rather than proof.
- Doing a quick check after moving a monitor: Browse the patterns to notice obvious visual changes before returning to your usual work.
Tips for a useful HDR Test
The contrast-reference values are RGB values, with the same value used for each channel: 0, 2, 4, 8, 16, 32, 64, 128, 192, 224, 240, 248, 252, 254, and 255. They are repeated on black and white. Black/white level modes show black patches from RGB 0 to 32 and white patches from RGB 224 to 255. Compare adjacent patches by eye; the values label the references, not a measured result from your monitor.
Keep viewing conditions steady when comparing settings, and change one setting at a time. If bright patterns cause discomfort, stop the test. For a more focused check of dark or light shades, try the Black Level Test or White Level Test.
Limits of HDR Test
HDR Test renders SDR RGB values only. It can help you compare labeled tones visually, but it is not a calibrated measurement, and the browser reports do not certify HDR activation, peak brightness, HDR10, Dolby Vision, or your panel’s capability. What appears on screen can vary with the browser, display settings, and the display itself.
Use this as a first visual check, not proof that a monitor meets an HDR specification. If you need verified HDR performance or a calibrated brightness value, use appropriate measurement equipment or ask the display manufacturer. If a suspected hardware issue persists across patterns and settings, contact the seller or manufacturer for assessment.