Lighthouse is an open-source, automated tool for improving the quality of web pages. You can run it against any web page, public or requiring authentication. It has audits for performance, accessibility, progressive web apps, SEO, and more.
To check the performance of the page we can use Lighthouse extension in chrome browser.
Navigation:
Open Chrome Browser > Browse a page > Right Click > Inspect > Lighthouse
There are Three modes in Lighthouse,
- Navigation mode: Analyzes a single page load.
Users are able to assess a single page’s performance and load time. Depending on our criteria, we have a lot of categories to choose from.
- Timespan mode: Analyzes an arbitrary period of time, typically containing user interactions.
Users can use this to check the specific load times of multiple pages based on user actions (manually) and to assess the overall performance of the website.
- Snapshot mode: Analyzes the page in a particular state.
We can also print the result and check overall details of the page.
Apart from the performance results the best practices sections are shown, which helps the developers to optimize the page.
Check the Doc for more details: https://github.com/GoogleChrome/lighthouse/blob/HEAD/docs/user-flows.md