Pixlr is an online design application that allows you to create design elements without relying on a desktop application. The application is not template-based, but rather a full-fledged editor, so it requires a bit of skill. However, it allows for a lot of flexibility and creativity. The free version will store your images in the cloud and offers a wide range of design functionality. To create a YouTube video thumbnail using Pixlr, log in to your account. If you don't have a Pixlr account, create a new one. For the purpose of creating a YouTube thumbnail, the free version should cover most people's needs.