Selenium is faster because it executes the code in the browser, while Puppeteer runs the code on the server. However, Puppeteer has more functionality than Selenium because it can also manipulate the DOM and take screenshots. If you need greater control over the page or you need to run scripts on a remote server, then Puppeteer is a better choice. If you just want to execute code in the browser and don't need any special features, then Selenium is a better option.