Lighthouse
Type: product (auditing tool by Google) | Domain relevance: Lab-based performance/accessibility/SEO auditing — useful for direction, but not the truth for Core Web Vitals ranking.
Summary
Lighthouse is Google’s automated auditing tool (performance, accessibility, SEO, best practices). A recurring lesson in the wiki: Lighthouse is lab data, not field data — Improving Core Web Vitals, A Smashing Magazine Case Study shows a site can be Lighthouse-green yet still fail Core Web Vitals in the field (CrUX/RUM), because Google ranks on real-user data. Also used for CI accessibility audits (with axe-core).
Key Facts
- Lab auditing for performance/a11y/SEO; runs in CI.
- Lab ≠ field: green Lighthouse can still fail real-user CWV.
- Complements (doesn’t replace) RUM / CrUX field data.
In the Sources
| Source | Context |
|---|---|
| Improving Core Web Vitals, A Smashing Magazine Case Study | Lab-vs-field divergence — Lighthouse green, field amber. |
| Web Development Best Practices 2026: Engineering Guide | ”Lighthouse is just a direction; RUM is truth.” |
Related
Entities: Google, Vercel Concepts: Core Web Vitals, Web Accessibility (WCAG 2.2 AA), CI/CD & Automation (DORA Elite)