@ricmacRichard MacManus Looking at their methodology, a web page fails the check if there is at least one element with low-contrast text in the DOM. That's why they additionally provide the error density as context.
It's not hard to imagine why the percentage is relatively high then. Even if the main text is black on white, headings or menus are often in different colours.
@lukeapfel 
thankfully my website has no text contrast issues. I did discover, however, that there is an alert for "Redundant alternative text", which I didn't even know was a thing. Seems a bit odd to recommend no alt text, but I will bear it in mind going forward. #accessibility
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