How to make a YouTube thumbnail with AI (that matches your video)

Your thumbnail and title are what people decide on before they ever see your video. The style that dominates YouTube is simple: two to four huge words with a thick outline, one keyword in a contrasting colour, a cut-out subject on one side and a glowing background. Here's how to make one — and how to make it consistently, so every thumbnail on your channel looks like it belongs.

The size rules

• 1280 × 720 px (16:9) is YouTube's recommended size; the minimum width is 640 px.
• JPG, PNG or GIF, under 2 MB.
• Readable at small sizes. Thumbnails show at a fraction of that size in search and on phones — if the words aren't readable at 200 px wide, they're too small.

Check the details on YouTube's own thumbnail help page.

Design tips

• Two to four words, maximum. The title does the explaining; the thumbnail adds intrigue.
• Highlight one word — the number, the surprise — in yellow or your accent colour.
• One subject, cut out, large, on the right. A face or the product reads best.
• High contrast: light text with a black outline on a dark background.
• A small tag ("TESTED", "NEW") can add context in one word.

Don't mislead

YouTube's policies prohibit thumbnails that mislead viewers about the content — and misleading thumbnails lose viewers fast anyway. Only show what the video actually delivers: if the thumbnail asks "Cold for 24 hours?", the video should test it.

Make it with Claude Opus 5.5 (or any agent)

The free Thumbnail Maker Skill renders the thumbnail as a PNG on your machine:

Make a YouTube thumbnail that says "Cold for 24 hours?" with "24" highlighted, bottle.png and a "TESTED" tag. PNG at 1280×720.

Your agent confirms the words, validates the image and renders the PNG in seconds — make three variations and pick the strongest. It can also render a three-second animated version of the same design for Shorts or an intro. More on how this works: Claude Opus 5.5 video generation.

FAQ

Can I use my own photo? Yes. A cut-out PNG with a transparent background gives the classic look.

Can I test thumbnails? Render several variations from the same file and use YouTube Studio's thumbnail testing where it's available to your channel.