When should you use Text has enough contrast?

Run this on every page a customer reads. Contrast is the accessibility failure people notice without any assistive technology — in sunlight, on a dim laptop, with ageing eyes — so it protects everyone, not only readers with low vision. Run it at the widths you care about: text moves over different backgrounds as a layout reflows.

It does not judge text drawn inside images, because there the text is pixels and no colour is declared; a banner with words baked into a photo needs a person. It is also not a design-quality score: a page can pass at 4.6:1 everywhere and still feel washed out.

light grey text on white; text on a brand colour that is too close in value; small text that misses 4.5:1

A failure names the element and its measured ratio against what the browser actually drew behind it, with the size that decided which minimum applied. Text below the minimum is hard to read for people with low vision and for everyone in poor conditions. Text over an image, gradient or overlapping element cannot be measured from colours alone; it is listed for review, never failed.

The minimums are WCAG 1.4.3's and are not adjustable: 4.5:1 for normal text and 3:1 for large text (24px, or about 18.7px bold). Disabled controls, hidden text and logotypes are exempt, exactly as the criterion defines them.

SchemaFirst.org publishes community-governed standards for digital QA. ArbiterQA is a supporter and commercial licensee of those standards; citation does not mean SchemaFirst operates ArbiterQA.