YouTube thumbnail tester
Open your thumbnail and see it where viewers meet it: among other videos on the home feed, in search, in Up next and on a phone, in light or dark mode, with your own title. The image stays on your device.
On YouTube
Your thumbnail12:34
Your thumbnail goes here
Your channel
123K views · 2 days ago
What to look for
- Up next is the hard test. It shows thumbnails 168 pixels wide. If you can't read your text there, most of your viewers on a laptop can't either.
- Squint at the home feed. The other videos are grey on purpose: yours has to stand out from a screen full of colour, so it needs one clear subject and strong contrast.
- Check dark mode. Many viewers use it. Thumbnails with dark edges can melt into the page.
- Mind the corner. The video length covers the bottom right. Keep text and faces out of it.
- Read it with the title. The thumbnail and title should say different things that add up, not the same words twice.
Text too small?
Text under about 14 pixels tall at 168 px wide is hard to read. The thumbnail font generator checks every font at that size for you, and gives you the text as a transparent PNG to put back on your thumbnail. The text size guide explains how big is big enough.
Frequently asked questions
Is my thumbnail uploaded anywhere?
No. The image opens in your browser and is shown from your device. Nothing is sent to a server, and it's gone when you close the page.
What size should a YouTube thumbnail be?
YouTube recommends 1280 × 720 pixels (16:9), at least 640 pixels wide. The tester tells you if yours is a different shape or smaller.
Is this exactly what YouTube looks like?
It's close, not exact: the sizes match YouTube's common layouts, but YouTube changes its design often and varies it by device. Use it to judge readability and contrast, not pixel positions.
Can I test a Shorts cover?
Yes. Tall images switch to the Shorts view automatically, or choose Shorts 9:16 above the preview.