Yellow on white. Red on crimson. Thin white type on a sky. These combinations look fine on a calibrated monitor and disappear in a bright backyard on a phone. This tool takes two hex colors — overlay text and a sampled background — and reports a contrast ratio with a pass/fail for small type.
It is not a full image histogram. Sample the worst patch behind your letters. If that patch fails, add a stroke, a plate, or a shadow until it passes.
How to use this tool
- Pick the text color from your overlay.
- Pick the background color from the busiest area behind the letters.
- Read the ratio and the small-text verdict.
- Add a dark plate or outline if you fail, then recheck.
YouTube UI is high-contrast; your still should be too
Dark theme surrounds tiles with near-black. Light theme surrounds them with near-white. A mid-gray thumbnail with mid-gray type loses to a simple high-contrast face. You do not need WCAG AAA for art, but you do need a ratio that survives shrink.
Professional notes
- A 4px hard stroke around type is a YouTube classic because it works.
- Faces also need contrast against backgrounds — hair on a dark wall vanishes.