benchmark

To detect performance regressions in a PR workflow, compare real page performance across builds using saved baselines for page load times, Core Web Vitals, and resource sizes. The system reports deltas against thresholds to identify regressions early.

Baseline tracking requires per-page metrics including TTFB, FCP, LCP, DOM Interactive, DOM Complete, and resource timing data. These establish traceable performance baselines for pages and bundles to track trends over time.

Baseline-based performance testing works by collecting navigation and resource timing data against a URL, saving those metrics as a baseline, and then comparing before and after states on every PR to report deltas against thresholds.

Yes, you can measure real page performance across builds without external dependencies by running a full baseline performance audit against a URL using the built-in browse daemon to collect timing data and compare deltas.

The best way to verify PRs meet performance budgets is to capture baselines for page load times and bundle sizes, then automatically compare before and after metrics on every PR to detect regressions early.