Apps & Tools

Contrast Checker (WCAG)

Check any two colours against the WCAG contrast requirements, or pick them straight out of an image. Works for interface text, captions, lower thirds, slides, and thumbnails alike.

Background Colour

Text / Foreground Colour

Thumbnail Preview

Your Thumbnail Title Here

Subtitle text · Brand name

Contrast Analysis

—

Contrast Ratio

Knowledge Base

How to Use the Contrast Checker

The Contrast Checker (WCAG) analyzes your YouTube thumbnail design to ensure text and elements are readable at small sizes. Upload your thumbnail image and the tool highlights readability issues that could hurt click-through rate.

Why Thumbnail Contrast Matters

On YouTube's homepage, thumbnails are 168x94 pixels. On YouTube search, 120x90 pixels. On mobile, even smaller. If your thumbnail is beautiful at full size but unreadable when tiny, it won't get clicks. Contrast is critical.

Thumbnail Best Practices

High Contrast: Light text on dark background or vice versa. Avoid light text on light background.
Bold Fonts: Thin, delicate fonts disappear at small sizes. Use heavy sans-serif (Impact, Oswald, Montserrat Bold).
Large Text: Minimum 24pt, 36pt+ is safer. No thin text smaller than 20pt.
Focal Point: Put the most eye-catching element in the center. Avoid clutter on edges.
Face Dominance: A large face with expression gets 30% more clicks than landscapes or objects.

A/B Testing Thumbnails

Create 2-3 thumbnail variations and upload the same video with different thumbnails. YouTube Studio shows click-through rate. Use the winner for similar future videos. Test bold colors, face expressions, and text phrasing.

FAQ

Q: Should my thumbnail match my brand or optimize for clicks?
A: Optimize for clicks first. Brand consistency is secondary to viewership growth. Your channel's subscriber base becomes your brand over time.

Q: Are all-caps titles better than title case?
A: ALL-CAPS is more impactful at small sizes. But multiple videos with all-caps can look spammy. Mix it up.