サムネる

This is a service that creates YouTube thumbnails by simply selecting colors and styles, then typing text. The background image is drawn by AI based on the words you type, and the text is placed by a program, so the characters you type appear exactly as written. The text size that's readable in smartphone lists is also automatically determined. Free up to 5 images per month (no credit card required), paid plans start from 1,980 yen per month. There's also a login-free option called "見え方チェック".

We designed it so that AI doesn't draw the text. We only ask AI to create one background image, and layer the text using a program. The darkness of the text background is determined by measuring the background pixels and finding a value that doesn't fall below a contrast ratio of 4.5:1. You can do everything from selecting colors to downloading on a smartphone alone.