Contrast checker

Compare two colors against WCAG text thresholds.

On your device · No account

Privacy details

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.

Your input

Background HEX color

Options and local file

Open a text file on this device

Optional settings apply only to this tab.

Your result

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

Contrast checker explained

Calculate the WCAG 2.2 contrast ratio between two opaque sRGB colors. Normal-text and large-text thresholds are reported separately, using the full ratio before rounding for display.

Next: CSS layout generator

Next: PX to REM converter

A worked example

Black on white has a ratio of 21:1 and meets the listed text thresholds. Identical foreground and background colors have a ratio of 1:1.

Before you use the result

Contrast alone does not establish accessibility. Transparent colors, gradients, images, focus indicators and rendered text size need separate review. Large text is at least 18pt regular or 14pt bold.

Cite this page

Citation style

ToolOctopus. “Contrast checker.” Updated 2026-09-20. https://tooloctopus.com/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.