Performance Benchmark Baseline
By l i n h · Published · Updated
Establishes a performance baseline for load and Core Web Vitals, with the numbers to beat and a record of exactly how they were measured.
Prompt template
## Performance Benchmark Baseline Measure a performance baseline I can compare future changes against. - Application URL or local command: [text: Where it runs] - Pages or endpoints to test: [textarea: List of routes] - Device and network profile: [dropdown: Desktop fast, Mobile mid-range 4G, Mobile slow 3G] - Tooling: [dropdown: Lighthouse, WebPageTest, k6, Playwright traces] - Traffic expected: [text: Concurrent users at peak] - Targets if any: [text: e.g. LCP under 2.5 seconds] Define the method before running anything so results are repeatable: tool and version, device and network profile, cache state, region, and number of runs. Run each page at least five times and report the median and spread rather than one run. Record Largest Contentful Paint, Interaction to Next Paint, Cumulative Layout Shift, Time to First Byte, and total transfer size. For backend endpoints under load, record requests per second, p50 and p95 and p99 latency, and error rate at the expected concurrency. Compare to the stated targets and the published Core Web Vitals thresholds, then list the numbers to beat. Add the top three suspected bottlenecks with evidence. Return a table plus a method section another person can re-run.