9 Oct 2022
  • Website Development

Maximizing Web Performance with Google Lighthouse (Complete Guide)

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By Tyrone Showers
Co-Founder Taliferro


Google Lighthouse is a Google Developer tool that helps measure the quality and performance of your website. Initially released in 2017 as an open-source project, it has gained popularity among developers and website owners who want to see how they can improve their websites. The lighthouse report offers valuable insights into many aspects of your site that you may not have thought about or even considered before: accessibility, SEO, performance, and more. This article will cover how to use the Lighthouse tool, what it does, best practices for using it effectively, and much more.

Google Lighthouse is a tool that helps you test the performance of your websites. It can be accessed right in Chrome's DevTools, or by running it on any URL. It runs a series of tests and grades your site on how well it performs as a whole. It analyzes your pages and provides actionable feedback to help you improve them.

The best way to think about this is like an end-to-end test for your web app: it measures how quickly pages load, whether they're usable, and if they are accessible (including supporting keyboard navigation). The results from these tests are then run through an automated grading system that gives each page a score based on these factors. You can install The Lighthouse extension in Google Chrome by downloading it here:

How to access Lighthouse

Lighthouse is a Google Chrome extension, so you'll need to install it first. It's available for Mac, Windows, Linux, and Android. Once you've installed Lighthouse, head to the Chrome Web Store page and click on 'Add to Chrome. A dialog box will appear asking if you want to do this—click 'Add Extension.' You'll know it worked when you see a little lighthouse icon in your browser toolbar.

The Lighthouse report

The Lighthouse report is a set of audits that run against your website. The report gives you a score and a list of recommendations. You can also download the report as HTML or JSON for further analysis. The Lighthouse report is divided into four sections: performance, accessibility, best practices, and SEO. These sections are explained below with examples from our own experience using Lighthouse on our website.

How Lighthouse Scores Your Site

Lighthouse is an automated web auditing tool that helps you find, fix, and verify the quality of your web pages. It's a scorecard for your site's performance, accessibility, and best practices.

Best Practices

Here are some best practices to keep in mind:

  • Use progressive enhancement. This fundamental concept ensures that your site works even if JavaScript is not enabled or the browser does not support it. It's also used to provide a better experience on lower-end devices.
  • Use a mobile-first approach. This means you should start with small screens and then build up from there when designing for larger ones (instead of creating full desktop displays).
  • Employ responsive design whenever possible. Responsive design refers to serving different stylesheets depending on the device being used (iPad vs. iPhone vs. desktop computer) so that users get the best experience possible based on their device type/browser version/etc., without requiring any unique code for things "to work" properly across all available platforms at once - which could become unmanageable quickly.


This section provides information on how quickly your website loads, its performance on mobile devices, and some tips on improving it further in the future.

Lighthouse has a Performance tab that checks if your website is optimized for speed. It checks the following performance metrics:

  • Load time
  • First meaningful paint
  • Time to interact (aka TTI)
  • Estimated network roundtrip time (RTT)
  • Estimated DOMContentLoaded time (DCL)


Accessibility is an important topic that can make or break your website. It's something you don't want to skimp on, but it's also one of those things that not everyone knows how to measure or fix. In this section, we'll cover what accessibility is, why it matters and how to test for it using Lighthouse.

This section rates the accessibility of your website based on certain guidelines set forth by Section 508 of the Rehabilitation Act (which requires federal agencies to provide access to persons with disabilities), WCAG 2.0 standards (an industry standard for making websites accessible) as well as ARIA roles (a specification developed by W3C to improve compatibility between HTML-based applications). You'll also find tips here if you want more information about what makes a good experience for someone using assistive technology like screen readers or braille displays.

Not only will Lighthouse display how to improve and optimize your website performance, but it also helps make your website mobile friendly, accessible, and more. The good news is that most of these problems are easy to fix once identified.


SEO is the process of optimizing your website to help search engines find and index your content. Lighthouse will check for best practices, including your use of meta-descriptions and titles, unique page resources, and appropriate canonicalization.

Lighthouse can help measure how well you've implemented SEO best practices on your site as it runs through several tests that analyze different aspects of a web page's performance:

  • Site speed (including caching)
  • HTTPS/SSL support (secure communication over the web)
  • Accessibility characteristics for people with disabilities or alternative needs


When you hear PWA, you may think of a submarine sandwich. It is an acronym for Progressive Web Apps. Progressive Web Apps are a set of technologies that allows you to create web apps that feel like native apps. They're helpful for creating responsive websites and adding offline capabilities and push notifications to your website.


After reading the above, you should understand how to use Lighthouse to test your website and identify areas for improvement. If you're looking to improve your site's performance, Lighthouse can be used in conjunction with other tools or resources like Google's PageSpeed Insights or The tool is handy as part of an overall strategy for optimizing web pages—mainly those already well-optimized but needs additional work. It's also helpful when measuring the accessibility of sites because it can provide recommendations on improving accessibility features like WAVE scores and adding alt text descriptions for images (which will help search engines understand what's being described). The Lighthouse tool can quickly identify performance issues and improve your site. This is a great way to get started with performance optimization. However, it's important to remember that many other tools are available for website developers who want more detailed data on their sites' performance.

Tyrone Showers