WCAG 2.0 · Level AA · Perceivable

WCAG 1.4.3 — Contrast (Minimum)

Text needs a contrast ratio of at least 4.5:1 against its background (3:1 for large text).

WCAG 1.4.3 at a glance

Level AA · Principle: Perceivable · Added in WCAG 2.0. Level AA is the conformance target for the ADA, EAA, and Section 508.

What it means

Text needs a contrast ratio of at least 4.5:1 against its background (3:1 for large text).

Who it helps

Low-vision users, colorblind users, and anyone on a bright screen.

Common failures

  • Light-gray text on white
  • Low-contrast placeholder and caption text
  • Text over busy background images

How to meet WCAG 1.4.3

  1. Darken text or lighten background to clear 4.5:1
  2. Define accessible color tokens in your design system

How to test it

Highly automatable — scanners and contrast checkers calculate the ratio.

Frequently asked questions

Is WCAG 1.4.3 Level A or AA?
WCAG 1.4.3 (Contrast (Minimum)) is a Level AA success criterion, introduced in WCAG 2.0. Level AA is the standard required by the ADA, EAA, and Section 508.
How do I test WCAG 1.4.3?
Highly automatable — scanners and contrast checkers calculate the ratio.

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