How to stay fast?
Brands that optimize for speed often find themselves regressing quickly. Website performance is like getting fit: a one-time effort is not enough, and a lifestyle change is required.
Performance budgets are one way to address this issue. A performance budget is a set of limits on metrics that affect site performance, similar to a financial budget where you set a limit and ensure you stay within it. A good performance budget usually combines different types of metrics; for instance, the budget for a product page might define thresholds for metrics such as Largest Contentful Paint, Cumulative Layout Shift, and Total Blocking Time.
Once established, a budget must be enforced, for example by integrating it into the build process and reporting workflows. Tools like Lighthouse can be included in continuous integration, and tests can be written to fail a build if key metrics fall below a set threshold. Regular dashboards or summary reports can also support visibility and accountability. Pinterest is one example of a company that implemented performance budgets to keep their fast experience fast, while brands like Experian now use site speed as a key metric in monthly executive KPI reports.
Further details on performance budgets are available in the guide on performance budgets, while a resource describing how to instill a performance culture and make speed metrics visible and tangible for stakeholders can be found in the report on how to report metrics.
