Contrast (Enhanced)
What this means
This is the stricter, AAA-level version of the contrast requirement in SC 1.4.3 Contrast (Minimum). Instead of the AA minimums of 4.5:1 for normal text and 3:1 for large text, this criterion requires at least 7:1 for normal-size text and at least 4.5:1 for large text. A color pairing can easily satisfy AA's 4.5:1 minimum while still falling well short of this enhanced 7:1 threshold — passing one does not mean passing the other. As with 1.4.3, this applies to real text and images of text, and does not apply to logos or purely decorative text. Because it demands noticeably higher contrast than most default design-system palettes provide, this is one of the harder AAA criteria to meet without deliberately choosing darker text colors.
Who it affects
People with low vision, including many who don't meet the legal definition of blindness but still need much higher contrast than typical AA-compliant designs provide, benefit directly from the enhanced ratio. This includes people with reduced contrast sensitivity from conditions like cataracts or glaucoma, for whom a 4.5:1 pairing that looks fine to someone with typical vision may still be difficult to read without magnification. It also helps people reading on devices with poor screen quality or in challenging lighting like strong glare, as well as anyone experiencing temporary visual fatigue during long reading sessions.
Code example
Bad
/* Body text at 16px (normal size): #767676 on #FFFFFF is 4.54:1 -- passes AA's 4.5:1 minimum but fails AAA's stricter 7:1 requirement */
.report-summary {
color: #767676;
background-color: #FFFFFF;
font-size: 16px;
font-weight: normal;
}Good
/* Same 16px text: #454545 on #FFFFFF is 9.59:1 -- comfortably clears the 7:1 minimum required for normal text under AAA */
.report-summary {
color: #454545;
background-color: #FFFFFF;
font-size: 16px;
font-weight: normal;
}How to test it
Use a contrast checker to sample the actual foreground text color and background color, then read the calculated ratio. First check the text's size: text at 18pt/24px or larger only needs 4.5:1 under this criterion, while smaller text needs 7:1. Many color pairs that already pass SC 1.4.3's AA thresholds will still fail here, so re-check every distinct text/background combination on the page against the higher bar rather than assuming an AA pass is good enough.