Color contrast checker

Compare a text color with its background and check WCAG contrast thresholds.

On your device · No account

Privacy details

Color contrast checker processes your input in this browser. Inputs and results are excluded from analytics. Recent tools save tool names, visit counts and last-visit times. Saved tools store only their names. Draft saving is optional and stays on this device; delete saved text with the draft controls. Loading text from a URL is optional and contacts that server; its URL and your IP address are visible to the server. An optional “Use in” action keeps a handoff in this tab. The next tool removes it on arrival and ignores it if more than a minute has passed.

Copy link includes the inputs you choose to share in the address. Anyone with that link can reopen them. Files and generated results are excluded. Password and key tools share settings only.

Text color

Background color

Your result

The quick brown fox

Enter your values.

Reset reloads the tool with its starting values and releases open files and device controls. Saved drafts stay on this device until you delete them.

Links include your inputs and settings. Anyone with the link can see them, so leave out private text. Files and generated results are left out; random draws run again.

Keyboard shortcuts

Updated 2026-09-20

Check text against its background

Contrast is the ratio between the lighter and darker relative luminance, after sRGB channels are converted to linear light. Normal-text AA requires 4.5:1; large-text AA requires 3:1. The tool compares the unrounded ratio before displaying it.

Next: Color picker from image

A worked example

Black text on white has a 21:1 contrast ratio. Identical colors have a 1:1 ratio and fail the text thresholds.

Before you use the result

Opaque sRGB colors only. This is a color-pair check, not an accessibility audit. Large text means at least 18 point regular or 14 point bold; antialiasing and other page content can affect readability.

Next: Image resizer

Cite this page

Citation style

ToolOctopus. “Color contrast checker.” Updated 2026-09-20. https://tooloctopus.com/color-contrast-checker.

Add an access date if your instructions require one.

Citation formatting uses citeproc-js by Frank Bennett and Citation Style Language styles. Licence and source code.