What problem does it solve? Web performance degrades gradually across pull requests, and without baselines nobody notices until load times become unacceptable. This Skill captures real browser timing data, compares it against stored baselines, and flags regressions before they ship. ## Core Features & Use Cases - Real-browser measurement: Collects TTFB, FCP, LCP, DOM timings, resource sizes, and request counts via performance.getEntries() in an actual browser session. - Baseline comparison and regression detection: Saves baselines per page and flags regressions using relative thresholds for timing, bundle size, transfer size, and request count. - Budget checks and trend analysis: Grades pages against industry performance budgets and tracks metric trends across historical benchmark runs. - Use Case: Before merging a PR, run a benchmark against your staging URL to confirm the new feature did not inflate the JS bundle or double LCP compared to the baseline. ## Quick Start Ask the AI to run a performance benchmark on your staging URL and compare the results against the saved baseline to detect any regressions.
