benchmark

Detect web performance regressions in continuous integration by comparing current metrics against established baselines. This skill flags timing increases, bundle growth, and degraded Core Web Vitals before merging code changes.

A Core Web Vitals and bundle size benchmark captures TTFB, FCP, LCP, DOM timings, bundle sizes, and request counts. It gathers real performance data from running pages using JavaScript evaluation.

Establish a baseline for page load times and resource bundle sizes by recording performance metrics for any set of pages. The recorded baseline is then used to flag regressions or warnings in subsequent runs based on configurable thresholds.

You can track gradual performance degradation over time using trend analysis features. This allows you to view historical performance data across multiple benchmark runs to identify slow declines in web application speed.

You need a running web application to measure LCP and page speed metrics because the skill requires the browse daemon's perf command. It uses JavaScript evaluation to gather real performance data directly from the active pages.

The best way to prevent bloated bundles from reaching production is to automate regression detection in your CI workflow. Comparing every pull request against a baseline catches bundle growth and request spikes before users are impacted.