The most common failure, and the most fixable.
THE REQUIREMENT
Body text needs a contrast ratio of at least 4.5 to 1 against its background.
Large text, roughly 18 point or 14 point bold, can be 3 to 1.
HOW TO CHECK
An online contrast checker. Enter the two colours and it reports the ratio.
Browser developer tools also report contrast for selected text.
WHAT USUALLY FAILS
Grey body text on white Text over photographs Light coloured buttons with white text Placeholder text in form fields Footer text, frequently the lightest on the site Disabled form controls
FIXING IT
Darken the text, or lighten the background. Usually darkening the text.
For text over images, add a dark overlay or place the text on a solid panel.
WHY IT MATTERS BEYOND COMPLIANCE
A visitor who cannot comfortably read your text does not read it.
This affects older visitors, anyone on a phone outdoors, and anyone with a lower quality screen.
THE REAL TEST
Your site on a phone, outdoors, in daylight. Harsher than any checker.
