Chrome Lighthouse: Audit and improve your website’s performance

What is the Chrome Lighthouse audit tool?

The Lighthouse audit report from Chrome is a phenomenal tool for evaluating and improving the performance of your website. It quickly identifies problems in terms of performance, structure, accessibility, and more so you can optimize your website for the best user experience possible.

The audit is divided into four main sections or domains: performance, accessibility, best practices, and SEO. While only one of these is labeled ‘SEO’, all of them are important for ranking on Google’s search results pages (SERPs), and it would be wise to achieve a high score in each of the sections.

It is possible to access Lighthouse from Chrome DevTools directly in the browser but it is easier to use the tool if you install the plugin from the Chrome Web Store.

chrome lighthouse website performance test
Chrome Lighthouse audit

Performance section

The first section in the Chrome Lighthouse report is all about speed and performance. The test uses six different metrics to calculate the overall performance score, and only results over 90 are considered good.

The test also presents some opportunities for you to improve the performance score of the webpage, as well as audits that have been passed with good results. Examples of these include:

  • slow initial server response times
  • identifies render-blocking resources
  • lets you know if caching and minification are active

Some factors like server response times will not be possible for you to change by optimizing your website, as it depends on your hosting environment. That’s why it is important to have a hosting provider with fast loading times. You get what you pay for, and cheap hosting is usually slow.

Unfortunately, website performance is often a trade-off between speed and functionality. Many apps and plugins with features such as image sliders, product carousels, dynamically inserted reviews, and Instagram posts can look great but also drags down website performance significantly. It is up to you as a website owner to decide which features are necessary for a good user experience and which features are not.

Accessibility section

The second section in the Lighthouse report is accessibility. These checks highlight opportunities for you to improve the accessibility and user experience of your website. Examples include:

  • good contrast ratios for easy readability
  • correct heading and document outline structure
  • optimal sizing of clickable elements on the page

Accessibility optimizations are not only important for ranking on Google Search but also for helping people with disabilities use your website. Correct heading structures and alt text descriptions of images can help people who use screen readers to navigate your site. Contrast ratios are important for people with vision impairments.

chrome lighhouse performance reccommendations
Lighthouse performance test

Best Practices section

As with the Performance and Accessibility sections, the Best Practices section of Chrome Lighthouse presents you with opportunities to improve the user experience of your webpage, along with audits that have already been passed. Examples of these include:

  • website is encrypted using HTTPS
  • page avoids front-end JavaScript libraries with known security vulnerabilities
  • images are served with the appropriate resolution

Many of these optimizations won’t be immediately visible to a website visitor but do affect issues like security, privacy, and compatibility with various standards of web technologies. Not only are these factors important for search ranking and user experience, but also for the security of your website.

SEO section

The SEO checks “ensure that your page is following basic search engine optimization advice”, according to Google. The SEO score is important as it directly reflects the web page’s ability to be ranked on Google Search, as well as how the page is presented on search results. Examples of the audits run include:

  • titles, meta tags, and alt text descriptors are filled
  • the page isn’t blocked from indexing on Google Search
  • the document has legible font sizes

If you want to optimize SEO on your WordPress website, it’s easiest to employ a plugin like Rank Math that makes it simple to edit meta tags, submit sitemaps, index pages, etc. At OptimizeWP, we use Rank Math on all websites we create and the experience has been great. Using an SEO plugin will affect speed minimally but the pros outweigh the cons.

Summing it all up

The Chrome Lighthouse audit tool provides you with a wonderful opportunity to easily check the performance, accessibility, and SEO score of your website. While it is not always possible or even necessary to get to 100% on all scores, you do want to get most of them in the green (above 90%).

High scores on the Lighthouse tests will go a long way to ensure your users a good experience, as well as better rankings for your website on Google Search. And the best of all: the report and opportunities to improve your website are free, so there is no excuse not to take advantage of this amazing tool!

Many of the opportunities for improvement presented require some degree of technical knowledge and expertise to implement. If your website is WordPress-based, this includes installing, removing, or tweaking third-party plugins, themes, and code. If you are not experienced in this, we recommend you reach out to us as we will be happy to help optimize your website for the best performance possible.