DisplayHDR 400, 600, 1000 and True Black: the tier number is not the whole brightness story

A VESA DisplayHDR tier is a certification level, not a promise that the entire screen can hold the tier number forever. Under the current DisplayHDR 1.2 criteria, VESA separately tests small-area peak luminance, full-screen flashes, long-duration full-screen luminance, black level, contrast, color gamut, color accuracy, bit depth and other behavior.

Source-checked: 26 August 2026 · Current criteria: VESA DisplayHDR CTS 1.2

First: “HDR support” is not the same as DisplayHDR certification

Many displays can accept an HDR10 signal. That tells you the monitor can participate in an HDR signal path, but it does not by itself establish how bright the panel gets, how dark its blacks are, how much color gamut it covers, or how accurately it reproduces HDR content.

VESA's DisplayHDR program exists to add a tested performance level on top of that basic capability. VESA says all DisplayHDR tiers require HDR10 support, but only products that meet the certification requirements may carry the DisplayHDR logo. VESA also warns consumers not to treat look-alike phrases such as “HDR-400” as equivalent to the official “DisplayHDR 400” certification name.

The tier number maps to one peak test, not every brightness test

Display brightness is luminance, measured here in candela per square metre (cd/m²), the SI luminance unit. Monitor listings often use the informal term “nits” for the same practical quantity.

Under DisplayHDR CTS 1.2, the headline tier number corresponds to the minimum result in an 8% center-patch test with a low-level background. VESA then applies separate full-screen tests because a display that can drive a small bright highlight may not sustain the same luminance when most or all of the panel is bright.

Those rows show why comparing only the tier number loses useful information. DisplayHDR 500 and 600 have different small-area peaks, but both are held to a much tighter black-level limit than DisplayHDR 400. The higher tiers also raise sustained full-screen requirements substantially.

Why peak and sustained brightness are separated

HDR images often contain bright highlights occupying only part of the screen: reflections, sparks, the sun, lamps, explosions, chrome, or specular highlights on water. A display can devote more electrical and thermal headroom to a small bright region than to a fully white screen.

That is not automatically a defect. The question is whether the behavior is predictable and suitable for the intended use. VESA therefore tests an 8% bright patch, a brief full-screen flash, and a long-duration full-screen condition separately. A product's real behavior can still vary with picture mode, automatic brightness limiting, panel temperature, local dimming algorithm and firmware, so certification should be treated as a verified floor under the test conditions rather than a complete review of every scene.

DisplayHDR 400 is more than a “400-nit sticker” under CTS 1.2

The entry tier is often dismissed as if it tests only a single brightness number. That description is outdated for the current specification. DisplayHDR 1.2 added and tightened several requirements, including DCI-P3 gamut coverage at the 400 tier, color-accuracy testing, static-contrast testing, black-crush testing and stronger bit-depth requirements.

VESA's current summary lists DisplayHDR 400 at a minimum 90% DCI-P3 (D65) coverage, a 1,300:1 static-contrast requirement and a maximum 0.4 cd/m² black level in the relevant test. Higher classic tiers tighten those requirements further. That still does not mean DisplayHDR 400 looks like DisplayHDR 1000—the point is that the certification represents more than peak luminance alone.

True Black is a different branch for emissive displays

OLED and other emissive displays can turn individual pixels extremely dark instead of relying on an LCD backlight. VESA created DisplayHDR True Black for that different display behavior. The current True Black family includes 400, 500, 600, 1000 and 1400 tiers.

The black-level requirement is the major clue: the current True Black performance table specifies a maximum black level of 0.0005 cd/m² in the relevant test across the True Black tiers. At the same time, full-screen brightness floors are lower than the corresponding classic tiers because emissive panels have a different brightness and power envelope.

VESA introduced the flagship DisplayHDR True Black 1400 tier on 8 July 2026. Its launch announcement highlights the 1,400 cd/m² peak requirement together with 700 cd/m² full-screen luminance, while retaining the deep-black behavior expected from the True Black program.

Do not compare classic and True Black tiers by the number alone

A DisplayHDR 600 LCD and a DisplayHDR True Black 600 OLED both carry “600” in the name, but the certification systems make different tradeoffs. The True Black branch emphasizes extremely low black levels for emissive panels, while classic DisplayHDR has separate contrast and local-dimming requirements appropriate to LCD architectures.

That means the tier number is useful within context. It is not a one-dimensional score that proves one monitor will look better than every monitor with a smaller number.

Local dimming matters on higher classic tiers

DisplayHDR 1.2 added static-contrast tests that make the backlight architecture more important. VESA states that the updated requirements effectively require one-dimensional local dimming or better for DisplayHDR 500 and 600, and two-dimensional local dimming or better for DisplayHDR 1000 and above.

That distinction helps explain why two LCD monitors with similar peak-brightness claims can have very different HDR performance. Bright highlights are only half the problem; the display also has to keep nearby dark regions dark enough to preserve scene contrast.

Color is part of the certification too

DisplayHDR 1.2 tightened color gamut and color-accuracy requirements. The current summary requires at least 99% BT.709 coverage across tiers. Classic DisplayHDR 400 requires 90% DCI-P3 (D65), while classic 500 and above and the True Black tiers require 95% in the current table. VESA also added a 96-color accuracy test measured at multiple luminance levels.

So a certification tier should not be translated into “this many nits and nothing else.” The standard is trying to qualify an HDR system that combines luminance, black level, contrast, color, bit depth and response behavior.

A practical buying workflow

1. Verify the exact official certification name. “DisplayHDR 600” is meaningful; a retailer's “HDR600,” “HDR Ready,” or “HDR compatible” wording is not automatically the same certification.
2. Check whether the monitor is classic DisplayHDR or DisplayHDR True Black. Do not compare tier numbers while ignoring the display technology and certification branch.
3. Read sustained brightness separately from peak brightness. This matters for bright desktop work, large HDR scenes and professional content use.
4. Check black level and dimming behavior. For LCDs, the local-dimming implementation can matter as much as the peak number.
5. Check the exact input path. A certified panel still needs the source, cable and port configuration to carry the desired resolution, refresh rate, bit depth and HDR signal. See the HDMI cable category guide and DisplayPort cable-label guide for the transport side.
6. Use independent measurements for model-to-model shopping. Certification establishes tested minima; a good review can show how a specific monitor behaves across window sizes, picture modes and real content.

Primary sources

• VESA Certified DisplayHDR — DisplayHDR CTS 1.2 performance criteria, for current luminance, black-level, gamut, contrast and bit-depth requirements.
• VESA Certified DisplayHDR — program overview, for the current tier families and certification guidance.
• VESA — DisplayHDR 1.2 announcement, for the May 2024 changes including tighter color, contrast and dimming requirements.
• VESA — DisplayHDR True Black 1400 announcement, published 8 July 2026.
• NIST Guide to the SI — luminance in candela per square metre.

Bottom line

Read DisplayHDR as a tested performance class, not as one brightness number. The headline tier tells you the small-area peak floor, while the current certification also tests sustained full-screen output, black level, contrast, gamut, accuracy and bit depth. For a purchase, verify the official tier, the classic-versus-True-Black branch and the monitor's measured real-world behavior rather than shopping by the largest “nit” number alone.