Thumbnail.AI

Thumbnail.AI is a simple and free tool that can generate video thumbnails for any purpose. It’s super easy to use, just add your video text, customize the image and background (optional), then download thumbnail ready images. If you don’t provide an image to use, then the AI will recommend a stock image that matches your video topic. There is also the option to use a template instead, which allows you to pick one of many popularly used YouTube thumbnails.