The contrast ratio between text and background is at least 4.5:1.
All users benefit from a good contrast between the text on your website and the background colour.
Some users with visual impairments need a stronger contrast than others to understand your content, so using the right colours is essential.
How to Pass
Make sure the contrast ratio between your text and background is at least 4.5:1.
Do this by:
- Using a light background and dark text; or
- Using a dark background and light text; and
- Using a colour contrast checker to verify your choice.
- Text that is 18 points or larger (or 14 points or larger, if bold) has a lower minimum contract ratio of 3:1
- Text that is purely decorative
- Text that is an incidental part of an image (for example, a man who is reading a newspaper or a landscape that happens to include a street sign)
- Brand logos
In CSS pixel terms, 14 points is 18.5 pixels and 18 points is 24 pixels.
Picking a contrast of at least 7:1 will also fulfil Guideline 1.4.6 – Contrast (Enhanced) at Level AAA.
Remember to ensure that all colours used conform. This includes links that change colour after being used once, and headings in menus and sidebars, as well as the main content.
Make sure that any embedded charts or images of charts have the minimum contrast between elements (for example, bars, axes and labels).
This guideline also applies to images of text (but you shouldn’t be using images of text, see 1.4.5 – Images of Text).
Luke, I have heard, but haven’t had time to look into it, that the BBC is considering making enacted contrast required on all content for mobile. I guess a responsive design would switch style sheets when the viewport gets down to mobile-ish dimensions. Worth looking into, if you can.
Hi Cliff, I hadn’t heard of that – I’ll see if I can dig around next week.
Anyone else heard anything about that or have a foot in at the BBC?
Great article! So often where I come across websites where the web designer (or client) seems to think it’s better to opt for what is “trendy” rather than what is beneficial to the end user. This tendency to stick to put “fashion” before functionality shows a clear lack of expertise and experience on the designer’s part when it comes to good user experience in proper professional web design and development.
Thanks Anthea, glad you enjoyed the article. It’s so important that companies know how to hire designers who know the fundamentals and won’t just throw up the latest fad for them.