Thumbnail
The still image shown for a video before it plays, such as the picture on a YouTube video or a Reel's cover.
On YouTube the thumbnail, with the title, decides whether people click. It's shown at 16:9, and YouTube recommends 3840 × 2160 pixels. The file limit is 50 MB when uploading on a computer and 2 MB from a phone. On Reels and TikTok, a cover image sets how the video looks on your profile grid.
Clear faces, few words in large type and strong contrast work best at small sizes. Like a hook, a thumbnail has to be honest about what the video delivers.
Free YouTube thumbnail resizer →
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