Thumbnail YouTube

What is a thumbnail on YouTube?

A thumbnail is the preview image that represents a video on YouTube — in search results, the home feed, suggested videos, and the embedded player. YouTube generates several thumbnail options automatically, and creators with a verified account can upload a custom image instead.

For regular videos you pick or upload a thumbnail right in YouTube Studio. Custom thumbnails for Shorts can currently only be added in YouTube Studio on a computer, and the account must also be verified.

Why the thumbnail matters

Together with the title, the thumbnail is the first thing a viewer judges a video by. It directly affects CTR — the share of impressions that turn into clicks — and through it the number of views. The YouTube algorithm compares how your packaging performs against other videos shown to the same audience, so a stronger image can lift the reach of the whole channel. See also our guide to what counts as a good CTR on YouTube.

Official size and format requirements

YouTube recommends that a custom thumbnail:

• has a resolution of 3840 x 2160 pixels for videos and 2160 x 3840 for Shorts, with a minimum width of 640 pixels for videos and a minimum height of 640 pixels for Shorts;

• is uploaded in an image format such as JPG or PNG;

• stays under the file-size limit: 2 MB for video thumbnails and 10 MB for podcasts on mobile, 50 MB for video, Shorts, and podcast thumbnails on desktop;

• uses a 16:9 aspect ratio for videos, 9:16 for Shorts, and 1:1 for podcast playlists.

Vertical videos with 16:9 custom thumbnails get an auto-generated 4:5 thumbnail on the home, explore, and subscriptions pages; the custom image still appears on the watch feed, watch history, and non-mobile platforms.

How to add a custom thumbnail

1. Sign in to YouTube Studio.

2. In the left menu, open Content (for a Short, open the Shorts tab at the top).

3. Open the video you want to edit.

4. Below “Thumbnail,” click Upload file, or choose Get suggestions for auto-generated options.

5. Click Save. Changes may take some time to appear on YouTube.

There is a daily limit on custom thumbnail uploads. If you see a “Daily custom thumbnail limit reached” error, try again in 24 hours. The limit varies by country and channel history, and Community Guidelines strikes reduce it.

Thumbnail policies

A custom thumbnail is rejected, and the channel can get a strike, when it contains: nudity or sexually provocative content, hate speech, violence, or harmful and dangerous content. Repeat offenses may lead to losing custom thumbnail privileges for 30 days or to account termination.

Misleading thumbnails — images that make viewers expect something that is not in the video — also violate YouTube policy. In milder cases YouTube may age-restrict the video or remove the thumbnail without issuing a strike. 3 strikes in 90 days can end in channel termination, so check the full official thumbnails policy before publishing.