There are several considerations for an HDR monitor:  

• If you are in a store, use my tests and sample images on any display you wish to evaluate: gregbenzphotography.com/hdr/#tests
• Peak brightness (in nits, aka cd/m^2).
  • 1000+ nits is where HDR gets truly exciting in general. Anything in this range will look excellent for HDR in a range of viewing conditions.
  • 600 nits OLED will also look amazing if you can keep the ambient light low (dark room or working at night).
  • This is the single most important criteria for HDR display. If the monitor doesn’t get bright enough, it will offer at best a mediocre HDR experience in anything other than a dark room.
  • The absolute minimum for HDR support is 400 nits. A monitor at this level will offer about 1 stop of HDR when viewed at half brightness. That can offer a good experience when viewed in a dim room, but you wouldn’t get much benefit if the screen is near a window or outdoors. Generally speaking, I wouldn’t get very excited about any 400 nits monitor, and many of these monitors still fail to offer a true HDR experience.
  • 600 nits is a noticeable step up over 400, but still just a decent HDR experience. I wouldn’t buy a new monitor just to get 600 nits. It’s just a nice bonus if you have it (and you’ll need to limit your brightness to about 50% of maximum to see real HDR benefit).
• For OLED displays, it is also important to review “sustained” or “typical” brightness or DisplayHDR certification.
  •  Mini-LED monitors tend to be much brighter than OLED at the same reported peak brightness. For example, a 1000 nits mini-LED might be able to show that brightness across the entire screen, while a 1000-nits OLED might only show 1-10% of the screen at that level (and perhaps only a few hundred nits if you try to max out the display).
  • Other than “tandem” OLED displays (such as the Apple XDR display in the M4 iPad Pro), most OLED’s will have significant limitations for full screen brightness relative to the reported peak value.
  • Manufacturers may communicate performance under these limitations as “sustained” (which is useful and generally means full screen capability) or “typical” (which is not a defined term but should give you some rough idea of what it can do in larger areas). A much more useful spec is the DisplayHDR rating, if the display has been tested/certified.
  • In general, anything with a 1400 or 1000 nits DisplayHDR certification list will likely offer impressive HDR.
  • Anything certified as Display HDR 600 True Black (which means OLED) should be a good option for use in darker environments. I wouldn’t buy a display for the 400-500 level, but it’s useful if you happen to already have it.
• Deep blacks
  • HDR quality is ultimately about achieving a greater dynamic range, and having a washed out black (not truly black) reduces dynamic range. How much you benefit from deeper blacks depends on your ambient environment. A bright room (or one with bright lights) will reflect light on the screen and may significantly reduce the apparent value of deep blacks.
  • Most monitors use a backlight to illuminate multiple pixels This is known as a “transmissive” display because the light is transmitted through the pixels (rather than emitted from each pixel individually). The LCD restricts the light to create pixels, but it cannot block 100% of the light, so black pixels are not  truly black.
    • This also may show “blooming” where black pixels near bright pixels show as grey because those pixels share the same backlight.
    • The best transmissive displays use “full array local dimming” (FALD). These use more than one backlight so that dark areas in the image may use a darker backlight or perhaps turn it off entirely. This allows for much darker blacks as it reduced bleed through, and often allows for true black in pixels which are not near bright pixels.
    • There are many variations of this approach and those with <100 zones don’t offer a lot of benefit. Look for ideally 500+ local zones.
  • Some monitors (such OLED or future “micro” LED displays) are “emissive” displays which emit light directly from the pixel. These monitors offer true black and significantly improve dynamic range (particularly when viewing in environments without bright ambient light).
    • You may see such monitors marketed as having “infinite” contrast (since you’re dividing the brightness white pixel by a black pixel that is considered to be 0 nits).
  • The difference with black levels will be very obvious when viewing FALD vs OLED in a dark room with content such as a star field (stars in the black night sky). These small bright areas will force a lot of backlight to affect the blacks in the FALD, while the OLED will retain deep blacks. So content which mixes small bright areas near deep shadows will suffer on FALD when viewed in a room dark enough to discriminate between true black and the monitor’s minimum black.
• Contrast ratio:
  • 600+ nits are often a great sign for quality, but not the entire story. Make sure the display offers a very high contrast ratio. 1000:1 indicates you’re mostly getting bright SDR (blacks won’t be very dark). The ideal is 100,000:1 or more.
• Anti-glare coatings:
  • Related to deep blacks and high contrast is the risk that a glossy monitor coating may create distracting reflections.
  • If you see clear reflections in a display in the location (and you could hold a phone or tablet in the area to help test), you may benefit.
  • On the flip side, anti-glare coatings tend to diffuse ambient light and may create an elevated black level if there is much ambient light (internal reflections probably aren’t a concern with dark ambient light, so blacks should improve under dark / night conditions).
• Calibration / Profiling
  • There is currently no ICC standard for HDR. As a result, it is important to get a monitor which is reasonable to highly accurate out of the box (ideally deltaE <1) or which supports hardware calibration in the monitor itself. You cannot use typical consumer colorimeters to profile HDR displays at this time (aside from supporting MacOS Fine Tune calibration for Apple displays).
  • Apple’s XDR displays are both accurate and support some unique Apple options for calibration.
  • ASUS ProArt monitors support hardware based calibration through their software utility.
  • HDR TVs offer a range of controls and some HDR monitors have controls such as RGB gain which may be used to help improve accuracy of the device. This works best if you use software like CalMAN to help test color accuracy (generally the EOTF for HDR displays is not well described or something you can easily validate). TVs sold in the last couple of years tend to offer pretty decent color accuracy out of the box.
• VESA DisplayHDR ratings can be helpful, but have some limitations you should be aware of:
  • Many great products are not rated (this includes all Apple displays, and their XDR displays are the gold standard for consumer HDR).
  • Their test methodology for peak brightness is helpful, but their contrast tests have been criticized for  allowing high ratings for monitors which lack local dimming (ie, poor blacks / dynamic range).
  • Why might a monitor have “1000 nits peak brightness” and yet only certify to “DisplayHDR True Black 400”? Most likely because the peak brightness either does not include enough pixels or cannot hold that level of brightness for a long duration. The display must be capable of showing the certified brightness in at least an 8% window, among other requirements. See the actual test specs here.
• Ports:
  • The bandwidth used for your display’s connection needs to support HDR (10-bit), resolution (such as 4K), chroma sub-sampling (444 is ideal for high resolution color), and refresh rate (you need at least 60Hz and 120 is ideal in photography for panning and zooming – plus other uses such as scrolling text). 
  • Your bandwidth is about 3x higher if your connection supports DSC (Display Stream Compression).
  • Minimum requirements for HDR:
    • HDMI 2.0 supports 4K HDR with 422 color at 60Hz (DSC is not supported). This is limiting, and HDMI 2.1 is clearly preferable.
    • DisplayPort 1.4 supports 4K HDR, with 444 color at 90Hz or 420 color at 144 Hz uncompressed, or up to 444 240Hz with DSC.
    • Note that Thunderbolt3 / USB-C with DP Alt Mode support both HDMI 2.0 and DP1.4.
  • Ideal for HDR:
    • HDMI 2.1 supports 4K HDR with 444 color at 120Hz (240 with DSC), or as much as 8K 444 at 120Hz with DSC.
    • DisplayPort 2.0 supports up to 4K HDR with 444 color at 120 Hz uncompressed or up to 8K with 444 and 240Hz with DSC.
    • Note that Thunderbolt4 / USB4  support DisplayPort 2.0 (there is no HDMI 2.1 Alt Mode over USB-C).
  • Use a good HDMI cable 
    • cheaper cables may lack HDR support in long lengths, and tend to be stiff, bulky, and hard to store.
    • I love the FIBBR 25 foot HDMI cable (note that fiber-optic cables are directional: you need to plug the end marked as #1 into the computer and #2 to the TV). 
• Apple vs 3rd-party monitors
  • You can NOT use an Apple monitor with Windows (it will work with basic support, but not as an HDR display).
  • Aside from that, any HDR-capable monitors or TVs should work very well with MacOS 15+ or Windows 10 / 11.
• How does the monitor look with a reference image?
  • There is no substitute for seeing the monitor yourself (just keep in mind that a great monitor may look terrible if the in-store settings are not correct).
  • If you are comparing monitors in a store, use Google Chrome to view my tests and example HDR images. Be especially sure to use test #8 to check the HDR headroom. This shows the real HDR benefit (keep in mind the display brightness directly impacts HDR headroom, so try dimming the monitor).
  • Note that that you can adapt brightness of your HDR display. It is important to adapt this slider so that standard content is not too bright, which will likely have the added benefit of leaving you with greater HDR headroom.
    • Check system settings to ensure HDR is enabled in your operating system display settings.
    • in Windows 10+ go to Display Settings / HDR and adjust the SDR / HDR Content Brightness slider. Try to use 0-50 (if this slider is set too high on a 400 nits monitor, you won’t have any HDR headroom at all).
    • in MacOS v15+, go to System Setttings / Display to adjust the brightness slider (when in HDR mode).
    • At the correct brightness this page should be comfortable to read.
• Non-HDR considerations:
  • Look for a monitor which covers most or all of either the P3 or Adobe RGB gamut. Most HDR images will still look with a limited sRGB gamut, but don’t limit yourself to colors from the ’90s.
  • You can experience HDR at any resolution and 4k resolution isn’t very important for photography with even 32″ monitors. Unless you’re editing 4k video, this is a place to consider saving some money.
  • If you are going to evaluate images for print with your HDR monitor, all the standard considerations apply in terms of even illumination, etc. That said, I’ve made a lot of large prints using a budget monitor with proper calibration and profiling. Learn more about considerations for printing with HDR workflows here.
  • High refresh rates are helpful for gaming, but not important for photography – and you may need use less than the maximum refresh rate in some setups to use HDR.
• GPU / video card / codec
  • Microsoft customer support indicated that there is no specific GPU or video card requirement to enable HDR in Windows 10 or 11 so long as you have an HDR monitor.
  • I’m not 100% confident that there aren’t exceptions to that, but I am not aware of any at this time.
  • Apple explicitly lists their compatible HDR hardware here.
• Considerations for testing in a store: There are numerous scenarios where HDR may not look optimal in a default store setting even for a great HDR monitor. Be sure to check all the following:
  • Make sure you pass test #1 on my page. If HDR headroom is not showing 1-4 stops: make sure HDR mode is switched on in the operating system settings, that you set the display as an extended (not mirrored) display in Windows, check that the external monitor’s controls are set for an HDR signal, and that the display brightness is not set too high if the monitor only supports 400-600 nits.
  • If you pass test #1, but test#2 shows a clipped gradient: that is likely because there is a ICC profile in use, try switching back to sRGB or the factory profile. This may also be caused by 3rd party software (I have seen this with both ASUS and MSI laptops).
  • One brand at CES 2024 showed soon-to-be released monitors which showed hard to read text in HDR mode (some very bright white edges to black text). The root issue was the sharpness setting in the display settings, setting it back to 0 fixed the issue. Hopefully it won’t ship with this as a default in the final shipping product, but I want to mention as it looked terrible on both their miniLED and OLED monitors until I changed this setting.