YouTube enables thumbnail A/B testing for all content creators

The video streaming platform YouTube is set to introduce a new 'Thumbnail Test and Compare' feature for all its channels in the coming weeks.
With this feature, content creators will be able to use three different thumbnails in any of their videos, allowing them to determine which thumbnail performs best.
During the test, YouTube will show different thumbnails to different viewers. After gathering sufficient data (which may take approximately two weeks), YouTube will analyze which thumbnail had the highest 'watch time share.'

Following this analysis, it will assign one of three possible results:

Winner: This designation is given to a thumbnail that significantly outperforms others in terms of watch time. The winning thumbnail will be selected automatically.

Preferred: This category indicates that one thumbnail probably performed better than the rest, though statistical certainty may be lower.

None: No thumbnail emerges as the clear victor. In this case, the originally uploaded thumbnail will be retained.

For the thumbnail that couldn't achieve superiority in the test, viewers can manually apply it to their selected video.