Introduction
This guide explains how to run a performance, SEO and accessibility report for your site using Google Lighthouse. This will allow you to identify improvements which will have the biggest impact on usability and SEO. It will also help to maintain a minimum level of accessibility, which is a legal requirement in many countries.
Requirements
- Google Chrome. If you don’t already have it, go to the Chrome download page and follow the instructions to install it: https://www.google.co.uk/chrome/
Skill Level
Basic knowledge of browsers to run the report.
Intermediate knowledge of web development to apply improvements.
Instructions
Time needed: 5 minutes.
- In Chrome, go the page on your website that you want to analyse.
- Open DevTools.
Either right / control click anywhere on the browser page and select Inspect, or go to the Chrome menu and select View > Developer > Inspect elements.
- Click the Lighthouse tab.
- Generate the report.
Tick the relevant options in the Categories section. Unless you only want a specific report, it’s best to leave all the options ticked.
Select the relevant option in the Device section. A majority of site visits are now on Mobile, so it’s best to select this option first. You can always run a separate report for Desktop.
Click Generate report. - Review the report.
Review the report, and follow the steps to improve performance.
The report is only saved in Chrome while you have the DevTools window open. You can print or save it offline by clicking the ellipsis (3 vertical dots) at the top right and selecting how you’d like to save the report.
More Info
Google guide to Lighthouse: https://developers.google.com/web/tools/lighthouse
Next Steps
Now that you’ve created a performance, SEO and accessibility report for your site, you should try to apply as many of the improvements it has recommended. You should run the same report each time you make improvements in order to assess how effective they’ve been.
If you haven’t already optimised the images on your site, this is likely to be one of the recommendations. If you have a WordPress site, see How to optimise images on WordPress using a plugin.