Contrast Checker

#3498DB vs Black

Aa #3498db text on #000000
Aa #000000 text on #3498db
6.66:1 contrast ratio · passes WCAG AA (normal text)

Try your own colors

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WCAG pass/fail for #3498DB vs Black

RequirementNeedsResult
AA — normal text 4.5:1 ✓ Pass
AA — large text 3.0:1 ✓ Pass
AAA — normal text 7.0:1 ✕ Fail
AAA — large text 4.5:1 ✓ Pass
UI components & graphics 3.0:1 ✓ Pass

#3498DB against other backgrounds

Formula

WCAG contrast is based on relative luminance — a weighted, gamma-corrected mix of the red, green and blue channels: L = 0.2126·R + 0.7152·G + 0.0722·B (each channel linearized from sRGB first).

The contrast ratio is then (L1 + 0.05) / (L2 + 0.05), where L1 is the lighter color's luminance and L2 the darker — giving a value from 1:1 (identical colors) to 21:1 (pure black on pure white).

Use it in code

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.element {
  color: #3498db;
  background: #000000;
  /* contrast ratio: 6.66:1 — passes WCAG AA normal text */
}