ChromeOS Flex runs on thousands of different systems, and a full list of certified models is available through Google. An old (or not) PC or Mac: Naturally, you need an old laptop or Mac to try ChromeOS Flex on.A USB 3.0 drive is preferred as it can speed up the installation process. A USB drive that's 8GB or more: You need this USB drive to create an installation media for ChromeOS Flex.
Google Chrome, Microsoft Edge, Vivaldi, and even Opera are a few examples.