Spanish - How to write lm instead of lim? 3.DOMCSSOM Headless tests are useful when performance or resources are limited. Why specifically do you need a headless Chrome instance? 2.CSSCSSOM DOMCSSOM. First, we launch a new headless browser instance, then we open a new page (tab) and navigate to the URL provided in the command-line argument. Loosely speaking, this means that what is possible to do with Marionette is a superset of what is possible to do with. Install Chrome and Download Chromedriver. For example, I disabled code that lazy-loads firebase-auth.js. If you want to use the headless option, you have to add options: Sounds good right? But this setup has a problem. We need to tell the page its HTML is already in place. Content available under the CC-BY-SA-4.0 license. Headless Chrome enables "isomorphic JS" between server and client. My favorite "feature" of this approach is that you improve loading performance and the indexability of your app without significant code changes! shut off features, don't lazy load non-essential resources, etc. Python WebScraper with BS4 and BeautifulSoup. Personally, I've found that YMMV with some of these tools, so definitely do your homework before committing to one. c. Using headless browser. Further Information: google developers updates To use headless mode, pass the headless argument when creating a new Browser instance. // Replace stylesheets in the page with their equivalent