Accessibility tools and resources - Validating HTML

You can’t rely on automated testing. A GDS audit of automated tools found that out of 142 known accessibility issues, the best tools only found around 30 to 40 percent.

Accessibility Insights

Accessibility Insights assessment extension is a Microsoft tool which is available as a Chrome extension. It will guide you through a manual accessibility assessment.

The manual accessibility assessment feature of Accessibility Insights really sets it apart from other browser extensions.

The guided manual assessment will give you a better understanding of how accessible your website is, and it provides a HTML report which can be downloaded and kept as evidence.

We have published guidance on how to use Accessibility Insights.

Colour contrast

Large text needs a ratio of 3:1 and normal text needs a ratio of 4.5:1. The minimum size to be considered ‘large text’ is 14 point if bold and 18 point if not.

Don’t get confused between point and pixels, they are not the same. A point is physical unit of length, and a pixel is a single dot on a screen. 1 point does not equal 1 pixel. 14 point is usually 19px and 18 point is usually 24px.

Colour contrast tools

You can use tools to measure your contrast ratios.

• Contrast Ratio
• WebAim colour contrast checker

WebAim WCAG 2.2 checklist

The WebAim WCAG 2.2 checklist is their recommendations for implementing accessibility principles and techniques. It is not a replacement for WCAG 2.2, but it might help you understand some of the criteria in a simpler format.

The list covers all the criteria from A to AAA, and the ones which are highlighted represent the criteria which are new to 2.2 and weren’t in older versions of WCAG.