What is Thumbnail?

Thumbnail explained

A thumbnail is the still image that represents a video across YouTube — on the home page, in search, in suggested videos and on your channel. YouTube picks a frame automatically, but most creators upload a custom thumbnail designed to attract clicks.

YouTube recommends custom thumbnails at 1280×720 pixels (16:9), at least 640 pixels wide, as a JPG, PNG or GIF under 2 MB. See the full thumbnail size guide.

Why it matters for thumbnails

Thumbnails are the first thing viewers see, so they influence almost every metric on YouTube. Read our thumbnail best practices to put this into practice, or browse the rest of the glossary.