Lighthouse is an automated open-source tool from Google that is integrated into the DevTools of Chrome, Opera, Arc, Edge, etc. (non-exhaustive list). It is designed to assist developers in improving the quality of their web pages by providing audits related to performance, accessibility, best practices, SEO, and compatibility with Progressive Web Apps. In this article, we will explain how to use Lighthouse to analyze and optimize your PrestaShop store.

Step 1: Access Lighthouse via Chrome DevTools

To begin your analysis with Lighthouse, follow these simple steps:

• Open Google Chrome (or another browser that includes Lighthouse). If you have not yet installed it, download it from the official Google Chrome website and install it on your computer.
• Access your PrestaShop store by entering the URL in the address bar of Chrome.
• Open the Chrome Developer Tools by pressingCtrl+Shift+I (orCmd+Option+I on Mac), or right-click on any page of your site and select "Inspect."

Step 2: Use Lighthouse to analyze your site

Once the DevTools are open, proceed as follows to launch an analysis with Lighthouse:

• Click on the "Lighthouse" tab in the top bar of the Chrome DevTools. If you do not see this tab, click on the two small arrows on the right to scroll through the available tabs.

  

• Set up your audit by selecting the categories you wish to analyze (Performance, Accessibility, Best Practices, SEO, and PWA).

• You can also configure the simulation conditions, such as the type of connection (3 G, 4 G) and whether you want to run the audit in mobile or desktop mode.

• Click on "Analyze page load" to initiate the audit. Lighthouse will analyze your page and generate a detailed report.

Step 3: Interpret the results of Lighthouse

The report generated by Lighthouse will provide you with a score for each tested category, as well as detailed recommendations to improve your site:

• Performance: Optimize the loading time and interactivity of your site.
• Accessibility: Ensure that your site is usable by all users, including those with disabilities.
• Recommended practices: Verify the security and other good practices of web development.
• SEO: Enhance the visibility of your site on search engines.
• PWA: Ensure that your website can be used as a progressive web application.

By clicking on one of the categories, you will receive a detailed report for that category:

Additionally, by scrolling down a little, you will get recommendations to optimize your site:

By clicking on one of the elements, you will have explanations allowing you to understand and resolve the identified problem:

Step 4 : Understanding Color Icons in Lighthouse Reports

In the reports generated by Lighthouse, you will find colored icons that help quickly identify the type of recommendation or issue being reported. These icons make it easier to prioritize actions to improve your site. Here is what each color signifies:

• Red (Error): These icons indicate critical errors that require immediate attention. They often point to issues that may have a direct and significant impact on user experience or site performance.
• Orange (Warning): Orange icons identify warnings, which are less critical than errors but nonetheless deserve to be reviewed. These issues may affect site optimization or lead to inconsistencies in the user experience.
• Green (Passed): The green icons accompany the elements that have passed the Lighthouse tests. These are the strengths of your site that comply with the recommended standards regarding performance, accessibility, best practices, and SEO.
• Blue (Information): The blue icons provide additional information that is not directly related to issues but may offer insights into the site configuration or suggestions for future improvements.

Each of these icons appears next to the test results in the Lighthouse report, allowing users to quickly understand the status of each analyzed item and to determine priorities for optimizing their website.

Frequently Asked Questions

How to resolve the issues reported by Lighthouse?

Each suggestion in the Lighthouse report is accompanied by documentation that explains the problem and offers concrete solutions. Click on the "Learn more" links to obtain detailed advice.

Can Lighthouse be used for sites other than those built with PrestaShop?

Absolutely, Lighthouse is a versatile tool that can be used to analyze any website, regardless of the underlying technology.

Is it necessary to have a score of 100 in every category?

No, in fact, very few sites achieve these scores. For example, the scores presented above are those of the Google Chrome download page. The ideal is to obtain the highest possible scores by resolving the maximum number of identified issues.