What this tool can catch
Enter a text colour and background colour to calculate the contrast ratio and compare it with common WCAG AA and AAA thresholds for normal and large text.
What still needs human review
It cannot inspect your whole site, account for text placed over images or gradients, or confirm that hover, focus, disabled, and error states all have enough contrast.
When to use this
Use it when choosing brand colours, designing buttons and forms, checking page sections, or reviewing a design system before implementation.
Next: see colour contrast examples, try the main checker, or use this with the Canadian checklist.