What is a YouTube thumbnail?
A YouTube thumbnail is the small preview image people see before they click a video. Together with the title, it is how viewers decide whether your video is worth watching.
Where people see it
Almost everywhere a video appears, the thumbnail comes with it. On a phone it is about the size of a stamp, so it has to read in a second.
Search results
Next to the title when someone searches. It is often the first thing their eye lands on.
Home feed
The page people open YouTube to. Your thumbnail sits in a grid of others all asking for the same click.
Up next and suggested
Beside or under the video someone is already watching. A big share of views come from here.
Shared links
When a video is posted in a chat, Discord or on social, the thumbnail is the preview picture.
Why it matters so much
Nobody can judge a video before watching it, so they judge the thumbnail and title instead. Two videos on the same topic can get very different views just from the picture.
If you skip it, YouTube shows a frame from your video. That still is rarely the moment that makes someone curious. A custom thumbnail lets you pick that moment and make it big.
YouTube thumbnail size
| Shape | 16:9 (wide) |
|---|---|
| Best size | 3840 x 2160 pixels (1920 x 1080 is fine) |
| Minimum width | 640 pixels |
| File types | JPG or PNG |
| File size limit | 2 MB from mobile, 50 MB from desktop |
Numbers from YouTube Help. More detail, plus Shorts sizes, on the YouTube thumbnail size page.
Examples
What a good thumbnail looks like
Good thumbnails show one idea, use three words or fewer, and put the player big. These layouts keep winning in gaming.
Questions, answered straight.
What is a thumbnail on YouTube?+
It is the preview image for a video. It shows in search, on the home feed, next to other videos and in shared links, and together with the title it decides whether someone clicks.
What is a custom thumbnail?+
One you make and upload yourself, instead of using a still YouTube picks from the video. Your account needs to be verified to upload one.
What size should a YouTube thumbnail be?+
16:9. YouTube recommends 3840 x 2160 pixels, the minimum width is 640 pixels, and the file should be JPG or PNG.
Does every YouTube video have a thumbnail?+
Yes. If you do not upload one, YouTube shows a frame from the video. Those stills are rarely the moment that would make someone click.
Can I change a thumbnail after uploading?+
Yes. In YouTube Studio open the video, go to Details and upload a new one under Thumbnail. It updates in a few minutes.
Make your first thumbnail free
90 credits on signup, no card. Pick your game and start from a layout that works.