What is the optimal contrast ratio for best readability?

If the background is a solid color (or all black or all white) then the relative luminance of the text can be maintained by making sure that each of the text letters have 4.5:1 contrast ratio with the background.

What is a 4 5 1 contrast ratio?

For “normal” sized text or images of text, the minimum contrast ratio is 4:5:1. For “large” text (or images of large text), the minimum contrast ratio is 3:1. Large or larger scale text is defined as 18pt at normal font weight or 14pt for bold font weight.

What is a good contrast ratio for accessibility?


WCAG recommends a 7:1 contrast ratio for users with vision loss equating to 20/80 vision, but 3:1 for large text since large print with wider character strokes is much easier to read at low contrast. This gives site owners more color choices for large text placement, such as in titles and headers.

What is the optimal contrast ratio?

Recommended contrast ratios

For people with moderately low visual acuity (20/40), the contrast ratio between text and its background should be at least 4.5:1. For large-scale text (at least 18-point normal or 14-point bold), a contrast ratio of at least 3:1 between text and its background is recommended.

What is a good contrast ratio for text?

A contrast ratio of 3:1 is the minimum level recommended by [ISO-9241-3] and [ANSI-HFES-100-1988] for standard text and vision.

Is a 3000 1 contrast ratio good?

So no, 3000:1 is nothing special. It’s 1000:1 and similar that is just very poor.

Is higher contrast ratio better?

A higher contrast ratio is better than a lower one, but the higher the contrast is, the less perceivable difference an additional increase will make—and there will come a point at which no continued increase (in absolute, objective terms) will be perceived by the viewer at all.

Is AA contrast enough?

WCAG 2.0 level AA requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text. WCAG 2.1 requires a contrast ratio of at least 3:1 for graphics and user interface components (such as form input borders).

How do you use contrast ratio?

Calculating a Contrast Ratio

Contrast ratios can range from 1 to 21 (commonly written 1:1 to 21:1). (L1 + 0.05) / (L2 + 0.05), whereby: L1 is the relative luminance of the lighter of the colors, and. L2 is the relative luminance of the darker of the colors.

What is contrast minimum?

3 Contrast (Minimum) (Level AA): The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for the following: Large Text. Large-scale text and images of large-scale text have a contrast ratio of at least 3:1; Incidental.

What is a 4.5 1 color contrast?

AA is widely considered the industry standard. The AA standard for color contrast is a 4.5:1 ratio between foreground (i.e. text, images) and background.

What is monitor contrast ratio?

The contrast ratio is the ratio between the luminance of the brightest white and the darkest black that a monitor can produce. Higher contrast ratios typically mean deeper blacks, which makes a big difference in overall picture quality.

What is AA and AAA in contrast ratio?

This is a score of at least 3.0 . AA – This is the sweet spot for text sizes below ~18pt. This is a score of at least 4.5 . AAA – This is enhanced contrast with a score of at least 7.0 . Think longer form articles that will be read for a significant period of time.

What is normal text WCAG?

Normal text: below 14pt bold or 18pt normal: AA: 4.5:1 (aim for this) AAA: 7:1 (but this is better)

What is high contrast?

If your photo consists of extremely bright and dark areas, then it’s considered high contrast. When it has a wide range of tones that go from pure white to pure black, it’s medium contrast. No pure whites or blacks and a range of middle tones means it’s low contrast.

What is AAA contrast?

Level AAA requires a contrast ratio of at least 7:1 for normal text and 4.5:1 for large text. Single A is viewed as the minimum level of requirement which all websites, apps, and electronic content such as documents should adhere to.

What is WCAG AA compliance?

WCAG 2.0 Level AA: Acceptable compliance

This conformance level is used in most accessibility rules and regulations around the world, including the ADA. To meet WCAG 2.0 Level AA conformance, the website is usable and understandable for the majority of people with or without disabilities.

Why is colour contrast important?

Colour contrast between text and background is important on web pages. It affects some people’s ability to perceive the information (in other words to be able to receive the information visually). Everyone who can see, sees things in different ways.

What is a good contrast color for blue?

In brief, complementary colors are any two colors opposite each other on the wheel. For example, blue complementary colors will be orange and yellow, and reds will be green. And when you use complementary colors together, they create an incredible contrast, which will help your design stand out.

What are the two most contrasting colors?

Opponent process theory suggests that the most contrasting color pairs are red–green, and blue–yellow. The black-white color pair is common to all the above theories.

What are high contrast colors?

White & black have the highest contrast, having the lightest & darkest values respectively. White on black, or the reverse, are great standard options for signage. Black & yellow together is another popular high contrast pair.

What are the 3 best colors that go together?

With this in mind, it just makes sense that color combinations — two, three, or more — can have even greater impact on the way a message is perceived, based on the hues a designer or artist chooses to combine.
Sets of 3 colors that go great together

  • Yellow, red, and blue.
  • Green, orange, and purple.
  • Teal, magenta, and gold.

Which combination has highest contrast?

Black and white create the highest contrast possible.

How do you find a good contrast color?

To increase contrast in your color scheme, you may need to adjust the value of a specific color—by making a yellow darker or lighter, say. Or perhaps adjust the saturation to vary the intensity.

What is a high contrast background?

The high contrast setting is an accessibility feature built into Windows that assists people with vision impairment. You may change the size and color of fonts and the background for ease of viewing. To enable high contrast, select your version of Windows below and follow the steps.

What are 4 contrasting colors?

Opposites Attract: 4 Complementary Color Combinations

  • Orange against blue.
  • Red complements green.
  • Yellow against purple.
  • Black and white.