HDR (High Dynamic Range) and color gamut are core indicators for measuring a monitor's color performance. HDR determines whether a screen can simultaneously present bright highlights and deep shadows, while color gamut determines how many colors a screen can display. Many monitors claim to support HDR and wide color gamut, but actual performance varies widely. Through online HDR test images and color gamut detection tools, you can intuitively judge whether your monitor's color reproduction capability meets standards.

This article will introduce methods for using HDR test images and videos, as well as detection techniques for common color gamuts such as sRGB, DCI-P3, and Adobe RGB. Without professional calibration equipment, you can complete a preliminary assessment through browser-based online tools, helping you determine whether your monitor is suitable for photo editing, video editing, or HDR viewing.

1. HDR Testing Basics: Understanding Dynamic Range and Brightness Levels

The core advantage of HDR lies in simultaneously preserving details in both extremely bright and extremely dark areas of an image. Online HDR tests typically display grayscale and light-dark transition images at different brightness levels to help evaluate a monitor's dynamic range:

  • Highlight Details: In areas approaching 1000 nits or higher brightness, whether texture and layering can still be seen rather than being blown out to pure white.
  • Shadow Details: In low-brightness areas approaching pure black, whether faint light and shadow variations can be seen rather than being crushed to pure black.
  • Light-Dark Transitions: Whether the gradient from brightest to darkest is smooth, or whether color banding or obvious brightness discontinuities appear.
  • Peak Brightness: The maximum brightness a monitor can achieve in HDR mode, typically measured in nits. The higher the value, the more pronounced the HDR effect.

Before testing, ensure that HDR is properly enabled on your system: Windows users should go to "Settings > System > Display > HDR" and enable "Use HDR," while macOS users should enable "High Dynamic Range" in the "Displays" settings. The monitor also needs to be switched to HDR mode.

2. How to Use HDR Test Images and Videos

Online HDR tests typically provide dedicated test images and short videos. By observing specific scenes, you can quickly assess HDR performance:

  • Grayscale Test Chart: Multiple grayscale blocks evenly distributed from 0% (pure black) to 100% (pure white). In HDR mode, adjacent grayscale blocks should all be clearly distinguishable, especially in shadow areas (below 5%) and highlight areas (above 95%).
  • Light-Dark Contrast Chart: The same image containing strong light sources and dark objects, such as backlit portraits or nighttime lighting. Observe whether highlights are overexposed and whether shadows retain detail.
  • Color Saturation Chart: Contains highly saturated color blocks. Check whether colors remain accurate in HDR mode without being oversaturated or distorted.
  • HDR Demo Video: Play HDR test video clips, paying attention to detail retention in scenes such as skies, lighting, and metal reflections, as well as the overall sense of depth in the image.

When testing, it is recommended to do so in a darker environment, eliminate ambient light interference, and set the monitor brightness to the HDR recommended value. If the monitor's HDR peak brightness is low (such as below 400 nits), highlight details may be lost, which is a hardware limitation that cannot be resolved through adjustment.

3. Color Gamut Detection: Differences Between sRGB, DCI-P3, and Adobe RGB

Color gamut represents the range of colors a monitor can display. Different color gamut standards cover different color spaces and are suited to different scenarios:

  • sRGB: The most basic and universal color gamut standard, covering approximately 35% of the visible color space. Daily office work, web browsing, casual gaming, and online sharing typically use sRGB, with the vast majority of content standardized on sRGB.
  • DCI-P3: A color gamut widely used in the film and television industry, offering approximately 25% more colors than sRGB, particularly richer in the red and green regions. Suitable for HDR video playback, film production, and high-end smartphone screens.
  • Adobe RGB: Targeted at professional photography and print design, offering approximately 50% more colors than sRGB, especially in cyan-green tones. Suitable for photographers and designers who require print output.

To determine whether a monitor's color gamut meets standards, you need to consider the use case. Everyday users only need 95% or higher sRGB coverage; for HDR viewing and video editing, it is recommended to choose a monitor with 90% or higher DCI-P3 coverage; professional photography should focus on Adobe RGB coverage. Online color gamut detection typically uses standard color block comparison charts to visually compare the colors displayed on the monitor against standard color values.

4. Online Color Gamut Detection Techniques

Without a calibration device, you can use online color gamut test charts for subjective evaluation:

  • Color Gamut Boundary Chart: Displays the standard color gamut triangles (such as sRGB, DCI-P3, Adobe RGB) compared with the monitor's measured color gamut. If the monitor's color gamut boundary is larger than the standard triangle, it indicates wider coverage.
  • Color Block Comparison Chart: The performance of the same color under different color gamut standards. Observe whether the color is pure and saturated, and whether there is color cast or color overflow.
  • Grayscale Color Step Test: Uses color bars at different grayscale levels to check whether the monitor exhibits color cast or inconsistent color temperature.
  • Skin Tone Test Chart: Skin tone is an important reference for evaluating color reproduction. Observe whether facial skin tones appear natural, without being too red, too yellow, or too gray.

Since visual assessment is influenced by ambient light and subjective factors, if precise data is needed, it is still recommended to use a professional calibration device for measurement. Online detection is primarily used to quickly assess a monitor's color tendencies and approximate color gamut coverage capability.

5. Common Problem Troubleshooting and Suggestions

  • Image appears washed out after enabling HDR: The monitor may not have correctly switched to HDR mode, or the HDMI/DP cable bandwidth may be insufficient. It is recommended to use HDMI 2.0 or higher, or DP 1.4 cables.
  • HDR highlights are overexposed: The monitor's peak brightness is insufficient to present the high dynamic range of HDR content. Try lowering the HDR content brightness or disabling HDR and using SDR mode.
  • Colors appear washed out in color gamut testing: The monitor may only support the sRGB color gamut, or the graphics card output may be set to "limited range." Check the graphics card driver settings and ensure the output is set to "full RGB range."
  • Colors appear oversaturated in color gamut testing: The monitor may have "color enhancement" or "vivid" mode enabled. Disable these features and retest.
  • Obvious grayscale banding: The monitor's color depth may be insufficient (such as a 6-bit panel), or the graphics card may not have 10-bit output enabled. Check display settings and try enabling higher color depth.

6. Summary

HDR and color gamut are important indicators for determining whether a monitor's color performance meets standards. Through online HDR test images, videos, and color gamut detection charts, you can preliminarily evaluate a monitor's dynamic range, color coverage, and reproduction capability without professional equipment. For everyday use, sRGB coverage of 95% or higher is sufficient for most needs; HDR viewing and video creation require higher DCI-P3 coverage and sufficient peak brightness. We hope the detection methods in this article will help you better understand your monitor and make informed purchasing or calibration decisions.