When you set a personal, business or family budget, you are setting a limit to your spending and making sure you stay within it. Performance budgets work in the same way, but for metrics that affect website performance.
With a performance budget established and enforced you can be sure that your site will render as quickly as possible. This will provide a better experience for your visitors and positively impact business metrics.
Here's how to define your first performance budget in a few simple steps.
Preliminary analysis
If you are trying to improve the performance of an existing site, start by identifying the most important pages. For example, these could be pages that have the highest amount of user traffic or a product landing page.
After you identify your key pages, it's time to analyze them. First, we'll focus on the timing milestones that best measure the user experience.
Under the Audits panel in Chrome DevTools, you'll find Lighthouse. Run audits on each page in a Guest window to record these two times: