Web Performance Self-Audit

Some of the most well known tools to run security checks on your websites are:

• PageSpeed Insights Google PageSpeed Insights (you also get the field data here)
• WebPageTest WebPageTest (very helpful with suggestions and improvement areas as well ability to manage regions and devices)
• Search Console Core Web Vitals Report (Google Search Console) (must do)

You can check out other sources and when to use one vs. not over at Web Vitals Tools

It is advised, and required, to run these as part of Maintenance Activities as well as during the Go-live process.