Introducing Headless browsers

What is a headless browser? No, it's not something from a horror movie. A headless browser is a browser that you can launch and interact with using a particular protocol over a particular communication transport, with no UI involved. This means that you will have one active process (or many processes, as we know how browsers are these days), but there will be no "window" for you to interact with the browser. I think that "windowless browser" would have been a more accurate name.

Available headless browsers

Both Chromium and Firefox support headless browser mode. It's important to mention that, at the time of writing this book, Firefox's headless mode was still experimental. That might sound bad, compared with the six browsers Selenium offers (https://www.hardkoded.com/ui-testing-with-puppeteer/selenium-browsers), but, as you might have noticed, I didn't say Chrome, I said Chromium. Chromium is the engine Chrome...