# Thumbnail

> The still image that represents a video before it plays — the biggest driver of click-through rate.

*Distribution*

*Also known as: cover image, cover frame*

Canonical: https://novaclipper.com/glossary/thumbnail

A thumbnail is the cover image a viewer sees before deciding to watch. On YouTube it is a custom graphic; on feed platforms it is the cover frame plus first caption. Either way it is the first thing judged and the main lever on click-through rate.

Effective thumbnails have one clear focal point, high contrast, readable text at small sizes, and a face or object that conveys the payoff. Testing variants is the fastest path to a higher CTR.

## Related

- [Free YouTube Thumbnail Ideas](https://novaclipper.com/tools/youtube-thumbnail-ideas)
- [Click-through rate explained](https://novaclipper.com/glossary/click-through-rate)

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