I tried every AI thumbnail maker so you don't have to
Your Channel
128K views · 2 days ago
Free tool
Thumbnail tester: see it in the real feed
Drop your thumbnail, type your title, and check how it reads on YouTube home, search, the sidebar, mobile and Shorts. Nothing leaves your browser.
Your image stays on your device.
How to test a thumbnail before publishing
- 1
Drop your image or click to choose a file (JPG, PNG or WebP).
- 2
Type the title and channel name you plan to use.
- 3
Switch between the views. The sidebar and mobile views show the smallest sizes: if your text is unreadable there, it is too small.
Is my thumbnail uploaded anywhere?
No. The preview is built in your browser with the file you select. Nothing is sent to a server.
What size should a YouTube thumbnail be?
1280 × 720 pixels (16:9), under 2 MB, in JPG, PNG or GIF. In the sidebar it is shown at about 168 pixels wide, so keep text short and large.
Why check the sidebar and mobile views?
A thumbnail that reads well full screen can vanish at small sizes. Most suggested-video clicks happen at these sizes.
Need a better thumbnail than the one you have?
Fleekio generates YouTube, Shorts, TikTok and Instagram thumbnails with your face and your own AI keys.
Try 10 generations freeNo card required