Color Contrast Checker
Adjust the inputs below. Results update as you type.
How it works
Color contrast ratio compares the luminance of text (or UI) against its background. WCAG success criteria set minimum ratios for normal text, large text, and UI components so content remains readable for more people. Enter hex colors to see whether a pairing meets common AA/AAA thresholds. Brand palettes often fail on small text even when they look fine to designers on bright monitors. Fix failing pairs by darkening text or lightening backgrounds, then re-test in context.
Input guidance
- Confirm date/time/unit settings before comparing outputs.
- If a task has optional fields, run both with and without them to understand impact.
- Save scenario variants when making practical decisions.
More examples to test
- Quick-pass example: run default assumptions for a first estimate.
- Refined example: update one assumption at a time to isolate impact.
How to interpret results
Use outputs as operational estimates and pair them with local constraints, business rules, or provider requirements.
When this can be inaccurate
Utilities can miss local policy details, special-case rules, and environment-specific constraints.
Change history
- July 2026: Quality-reviewed for publication with formula checks and explanatory copy updates.
Site-wide corrections also appear on the corrections log.
Find productivity tools for everyday workflows
General recommendation, not professional advice.
Frequently asked questions
Why are outputs slightly different from another tool?+
Different tools can use different rounding rules, default assumptions, and treatment of edge cases.
How can I improve estimate reliability?+
Use verified inputs from real records and re-run calculations after major assumption changes.