- 75.0%Native Contrast
- 25.0%Contrast With Local Dimming
The contrast ratio on monitors is the difference between the luminance of white and black areas that it can display at the same time. Higher contrast ratios typically mean deeper blacks in dark rooms, which makes a big difference in overall picture quality. This is mostly important for watching content with dark scenes, or with bright objects against dark backgrounds, particularly in HDR.
To test for contrast ratio, we measure the luminance of both white and black using a checkerboard pattern. Although luminance is measured in cd/m2, otherwise known as nits, the contrast between black and white is presented as a ratio. For example, a good contrast ratio is 3,000:1.
Test results
Test Methodology Coverage
The contrast ratio testing has remained the same since our initial Test Bench 1.0 in October 2017. This means that scores and results are comparable between monitors on any test bench. Learn more about how our test benches and scoring system work.
| Test | 1.0 | 1.1 and newer |
|---|---|---|
| LCD Type | ✅ | ❌ |
| Native Contrast | ✅ | ✅ |
| Contrast with Local Dimming | ✅ | ✅ |
When It Matters
Contrast is one of the most important aspects of picture quality, especially when watching or gaming with dark scenes. Images tend to look better on displays with a high contrast ratio, as it can successfully display deep blacks next to bright highlights. It's mainly noticeable in a dark room, especially when watching videos or playing games in HDR. A high contrast ratio can also help if you use a dark mode with white text on a dark background. A low contrast ratio can make content look washed out, as there's less of a difference between dark and bright objects.
You can see this with the examples below, where the monitor on the right can display deep, inky blacks next to bright highlights.
| Bad contrast | Fantastic contrast |
 Dell S2725QS |
 ASUS ROG Swift OLED PG27UCDM |
In a bright room, a higher contrast ratio isn't as important, as light reflecting off the screen causes the black levels to rise, negatively impacting the contrast ratio. We measure this as part of our ambient black level raise testing.
Our Tests
The goal of the contrast ratio test is to measure the difference between black and white levels when the monitor displays them at the same time. It's easy for a monitor to display deep blacks when the entire image is black, as it simply turns off its backlight. However, using a checkerboard pattern is more of a challenge for the monitor, so it's a true test of its real contrast ratio.
We measure the contrast ratio after calibrating the monitor. We aim for a white luminance of 100 cd/m², but as we can't get that exactly every time we perform the test, we still measure the white luminance of the center square using a Konica Minolta LS-100 Luminance Meter. We also measure the luminance of the four surrounding black squares and use their average to calculate the contrast ratio. To get this number, we divide the white luminance by the black luminance.
We don't list the actual black level that we measured during testing. However, if you want to know the approximate black levels we measured, assume that the white luminance was at 100 cd/m², and divide that by the contrast ratio. For example, a monitor with a contrast ratio of 5000:1 has an approximate black level of 0.02 cd/m².
As it's a ratio, there's no unit for contrast. Instead, contrast is normally expressed as 'X : 1,' with 'X' being how many times brighter white is than black. For example, a 5,000:1 contrast ratio would mean that the monitor emits white that's 5,000 times brighter than its black. The higher the contrast ratio, the deeper the blacks, and the better the picture will look.
Although we take these measurements with the backlight set to 100 nits, there's usually very little change in the contrast ratio of a display as you adjust the backlight. The more light the backlight emits, the more light passes through the pixels, causing the black levels to increase roughly linearly with the white levels.
Native Contrast
The Native Contrast ratio of a display represents the most basic contrast performance of the display, with local dimming turned off. To measure the native contrast ratio, we use a black and white checkerboard pattern to determine the black and white luminance, as described above, measuring the white center square and four surrounding black squares. We also take a picture of the checkerboard pattern, which is the photo you see in each review.
Dell S2725DC
The native contrast ratio number is important if the monitor doesn't have a local dimming feature, or if its local dimming performs poorly and you prefer not using it. On some monitors, you can only enable local dimming in HDR, so the native contrast ratio represents what the picture quality is like in SDR.
The final Contrast score uses a weighted system, with 75% of it coming from the Native Contrast result. That said, on monitors without local dimming, Native Contrast represents 100% of the score.
Contrast With Local Dimming
The Contrast With Local Dimming test is nearly identical to the Native Contrast test, but this time, we measure the contrast ratio with the monitor's local dimming feature enabled. On monitors with multiple local dimming settings, we use the setting we recommend based on the results of our Local Dimming test. In most cases, this is the highest setting available. That said, we don't take a picture of the checkerboard pattern with local dimming, as we only include the test result.
Having local dimming doesn't guarantee a better contrast ratio, though. Many edge-lit monitors fail to improve black levels, negatively impacting the contrast ratio and making the image look washed out. If that's the case, you may prefer disabling local dimming, in which case, the Native Contrast result is more important than Contrast With Local Dimming. However, Mini LED monitors usually have improved contrast with local dimming.
For monitors without local dimming, this test results in N/A. That said, even though OLED monitors don't have local dimming, as they don't have a backlight, the Contrast With Local Dimming result is the same as the Native Contrast (Inf:1). While we normally measure the contrast ratio in SDR, some monitors only allow local dimming in HDR. In this case, we must measure the contrast ratio in HDR, and we'll make note of it in the text.
Additional Information
Impact of Panel Technology
Monitors use different display technologies, each with advantages and disadvantages. Knowing which type of panel is used can already give you a good indication of what to expect in terms of contrast ratio. OLEDs can turn individual pixels on and off, resulting in a near-infinite contrast ratio for perfect black levels in dark rooms. This is the case with any OLED panel type, including QD-OLED and WOLED. As for LCD panel types, they don't have the same near-infinite contrast ratio because they can't turn pixels on and off like on an OLED. Generally speaking, VA panels have the best contrast ratio out of any LCD panel type, as they're better than IPS and TN displays.
| Panel Type | OLED | VA | TN | IPS |
|---|---|---|---|---|
| Contrast Ratio | Inf:I | 4,508:1 | 1,226:1 | 1,020:1 |
| Photo |  |
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Even within the same LCD panel types, it's normal for the contrast to vary a bit between units, even of the same model, due to manufacturing tolerances.
Learn more about LCD and OLED panel types.
Contrast Ratio VS Black Uniformity
While the contrast ratio test is a good way to show how well a monitor displays blacks, it doesn't necessarily mean it displays these blacks evenly across the screen. That's where it's important to also have good black uniformity. For example, an IPS with a low contrast ratio that has low black levels can evenly display the same black level across the screen, meaning it has good uniformity. On the other hand, there are VA panels that display deep blacks, but not evenly.
| Native Contrast: 1,304:1 Native Std. Dev.: 1.194% |
Native Contrast: 4,073:1 Native Std. Dev.: 1.931% |
|---|---|
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However, OLEDs have perfect black uniformity because they can turn individual pixels on an off, so there's no haloing around bright objects.
Learn more about our black uniformity testing.
Differences In Measurement Techniques
While we use a checkerboard test pattern, there are different ways to measure contrast. As such, the numbers we post may be different from those of manufacturers or even other reviewers, so you shouldn't compare our results to other sources. Some of the other methods include:
- Full On/Off: This involves measuring a full white screen and a full black screen. This is generally considered a less accurate way to measure contrast, and it isn't very realistic. Contrast measurements with local dimming tend to appear much better with this measurement technique, as it's easy for any monitor with local dimming to turn the entire screen off at once. Some manufacturers may post the contrast numbers using this method to make it seem better than how it actually performs.
- Half Screen Slides: This is similar to the above method, but with half of the screen black and half of the screen white. It's a bit more accurate than the above method, but still not very realistic.
- Small Samples: Similar to the full-screen method, but instead of large slides, contrast is measured using small slides that only cover part of the screen. This method isn't ideal either, as it isn't fully representative of content.
- ANSI Checkerboard: The asymmetric ANSI checkerboard pattern is the most similar to our checkerboard pattern, and is a widely accepted way of measuring contrast. This method measures the output in all 16 squares and averages the values for the white and black squares. It usually produces very similar results to our own.
How To Get The Best Results
There's no way to really improve the contrast ratio of a monitor, as it's a characteristic of its panel type. Calibrating the monitor usually gives you the best picture quality, though, as it can help better differentiate between bright and dark areas of images. There are different settings that can help improve its contrast just a bit, though, as you can see below:
- Contrast and Black Level: These adjust the black and white levels, with black level changing blacks, and contrast changing whites. That said, over-adjusting can make the image too dark or too bright, causing a loss of details.
- Local Dimming: The local dimming feature dims the backlight behind darker portions of the screen. It can deepen contrast, and it's worth using when implemented well. However, it can introduce issues like haloing around bright objects against dark areas, and when done especially poorly, it can dim the entire image.
- Gamma: Gamma doesn't control the depth of black, but it does control the amount of detail you see in dark portions of an image, like in shadows. If you find it difficult to make out details in dark images, consider making a slight adjustment to the gamma.
Backlight settings have a very minor impact on contrast, and so you should set it to whatever looks best in your viewing space. With LCD monitors, both white and black will become about equally brighter or dimmer when the backlight is adjusted, preserving the ratio. With OLED monitors, adjusting the brightness only increases the peak brightness; blacks are still perfectly black, and the contrast ratio remains Inf:1.
Conclusion
A monitor's contrast ratio indicates the difference between white and black levels it can display at the same time. A higher contrast ratio means the monitor can display deeper blacks, and by extension, have better picture quality. It's a very important part of picture quality, so if you want something that looks good, particularly in a dark room, be sure to get a monitor that has good contrast. OLED panel types have the best contrast ratios, but keep in mind that black levels rise in bright rooms on any display, so the contrast ratio is mostly important for watching content in dark spaces.