The Advantages of Headless Browsers

The internet is never standing still. It’s constantly evolving, changing, and expanding. The web used to be a chaotic network of outdated and barely functional websites. Nowadays, we have a highly advanced web with high-end websites built with user-friendly UI.


This beauty you see all over the internet is thanks to JavaScript. This programming language holds the entire web under control, allowing the internet to handle almost every interaction online.


The Advantages of Headless Browsers


Modern-day internet users have a variety of search engines and browsers at their disposal. Those browsers are so intuitive that they can easily understand and communicate with JavaScript. However, before developers can deploy a browser as a readily accessible product for users, they must put it through rigorous testing.


That is where headless browsers come into play. They are highly beneficial for web browser testing. Let’s see what headless testing is and how headless browsers can help with test automation.



Headless testing explained

Headless testing refers to the process of UI-based browser testing without displaying a graphical user interface (GUI). Testers run a script or a test against a browser but without using the browser UI. While headless browsers may not be particularly helpful in browsing the web, they are excellent tools for automating tasks and tests.


Headless testing allows software testers and developers to test a browser in a browser simulation environment that doesn’t have a user interface. That simulation environment runs like any regular browser with one difference – it doesn’t display any GUI.


For instance, if you want to run headless browser testing on Google Chrome or Chromium, you can use the Puppeteer framework that runs headless by default. Check out a Puppeteer tutorial to see how you can run tests using JavaScript commands.


Some of the most commonly used headless browsers are:

  • Headless Chrome
  • PhantomJS
  • SlimerJS
  • TrifleJS
  • HTMLUnit driver
  • Splash
  • SimpleBrowser
  • NodeJS
  • Zombie.js
  • Firefox


Headless browser testing is an essential part of software QA, and it helps automate tests and run them in any browser without the need for user interaction.


Since the digital business landscape moves towards a seamless software development lifecycle, developers need to give timely feedback to make the necessary changes. Automation testing by leveraging headless browsers speeds up the entire process.



Why it’s important

Headless testing matters simply because it’s automated, lightweight, and incredibly faster. It provides great speed, flexibility, scalability, and efficiency for automation testing.


It helps improve performance and speed as testers don’t have to run a browser to test it. Because of that, the system saves the processing power to execute tests faster and more reliably.


Headless testing also allows testing browser-less setups. Those setups are helpful when installing a browser isn’t an option, such as servers. In such situations, headless testing helps run automation tests.


Finally, headless testing helps developers and testers multitask, saving them time and effort. They can run tests in the background and use their devices and browsers to do something else.



Benefits of headless browsers

Let’s take a closer look at some of the advantages of headless browsers.


Automation testing

Headless browsers enable automation testing to check keyboard inputs, mouse clicks, submission forms, and more. They help automate a good portion of the software testing and delivery cycles, including installation, quality assurance, and development. Enabling automation testing that relies on JavaScript libraries makes headless browsers ideal for saving software development time, effort, and resources.


Layout testing

Like real browsers, headless browsers can render and interpret CSS and HTML elements. That’s why they can help with layout testing by performing various checks, such as determining the web page element coordinates and the default page width. They can also test AJAX and JavaScript execution and automate screen captures for layout testing.



Website performance testing is one of the most critical tests, and headless browsers help speed up the process. Since they load websites much faster, they allow testers to use the command line to test various performance tasks without loading GUI.


Web scraping and data extraction

Headless browsers are excellent web scraping and data extraction tools because they eliminate opening a website. Instead, you can quickly and automatically gather public data by scraping the HTML. Since you don’t need to render a full browser, you can scrape websites much faster.




Headless browsers are much faster than regular browsers, and they don’t have to load all the web elements and content that websites usually load for the best user experience. Due to their impressive speed, developers and testers commonly use them for various automation tasks, such as automation website testing.


They help automate a range of tasks on a website, such as its layout, page elements, and performance. Their speed also makes them perfect for web scraping and data harvesting.


Mozilla Firefox and Google Chrome are probably the most popular headless browsers. Although they have certain limitations, their advantages triumph over the disadvantages.