Site health checker. PSI 4-category composite.
Enter a URL. We pull all four Lighthouse categories from Google PSI (Performance, SEO, Accessibility, Best Practices), produce a composite health grade, and surface the top 5 fixes ranked by impact.
Enter a URL. We pull all four Lighthouse categories from Google PSI v5 (Performance + SEO + Accessibility + Best Practices), compute a weighted composite health score (Performance 40%, SEO 25%, Best Practices 20%, Accessibility 15%), and surface the top 5 audit findings ranked by impact.
Sources used
- Google PageSpeed Insights v5 API — the underlying Lighthouse engine
- web.dev Lighthouse performance scoring — category weight definitions
- pagespeed.web.dev — Google's official frontend (fallback if PSI rate-limits)
The URL is sent only to Google's public PSI API. Digital Heroes does not log queries. Recent checks use browser localStorage and stay on your device.
Privacy: URL is sent only to Google PSI. Digital Heroes does not log it.
Health is cross-category math.
Optimizing any single Lighthouse category in isolation usually degrades others. Heavy image compression lifts Performance but may fail Accessibility's contrast check. Aggressive lazy-loading lifts Performance but breaks Best Practices' deprecated-API audit. Single-page-app patterns improve perceived performance but commonly fail SEO's render-blocking audit. The composite score forces a balanced view by weighting Performance at 40%, SEO at 25%, Best Practices at 20%, Accessibility at 15%, and surfaces the top 5 cross-category fixes ranked by impact so you know which 1-2 changes lift the composite most.
Three operating principles. One, never optimize a single category to the cap — stop at 90+ and pivot to the next-weakest. Two, the top-5 fixes are the highest-weight failed audits Google's Lighthouse scoring assigns; fixing them is by definition the highest-impact work. Three, mobile-first scoring is the default because Google's mobile-first indexing (completed Oct 2023) means mobile is the ranking surface — desktop scores are usually 15-30 points higher and tell a comforting but irrelevant story.
Tools in the same cluster: Lighthouse Score Checker for the per-category deep-dive view. Core Web Vitals Checker for the field-data view (LCP / INP / CLS from real users). Website Audit for the broader compositie scorecard.
Five answers.
What does the composite health score measure?
The composite is a weighted average of all four Lighthouse categories: Performance (40% weight, since it has the largest user impact), SEO (25%), Best Practices (20%), Accessibility (15%). The 4-category view exists because optimizing any single category in isolation often degrades others — a heavily compressed image lifts Performance but might fail Accessibility's contrast check; aggressive lazy-loading can break Best Practices' deprecated-API audit. The composite forces a balanced view.
How is this different from Lighthouse Score Checker?
Lighthouse Score Checker shows the raw Lighthouse output with full per-audit detail across categories. Site Health Checker takes the same PSI response and produces a single composite grade plus the top 5 cross-category fixes ranked by impact. Use Lighthouse for deep diagnosis; use Site Health for the executive-summary view (board reports, sales decks, prospect screening).
What's a healthy composite score?
Above 90: top decile, hard to achieve without dedicated engineering. 80-90: healthy, common for well-built modern sites. 65-80: typical for production sites with technical debt. 50-65: significant issues, multiple categories failing. Below 50: serious technical debt, likely losing organic traffic + conversion. The composite weights performance at 40% so Performance failures show up disproportionately in the score.
Mobile or desktop strategy?
The check defaults to mobile because Google's mobile-first indexing (completed Oct 2023) means the mobile score is what Google uses for ranking. Mobile scores are usually 15-30 points lower than desktop because PSI throttles to a 3G mid-tier device profile. If your traffic is heavily desktop (B2B SaaS dashboards, internal tools), toggle to desktop for the more relevant score.
Does this tool save my data?
The URL is sent only to Google's public PageSpeed Insights API. Nothing is logged on Digital Heroes servers. Recent checks use browser localStorage and stay on your device only.
Composite below 80?
Our web development engagements run a 4-category Lighthouse audit, prioritize the top 5 cross-category fixes, and ship the work in a 30-day sprint. Most sites lift the composite 15-25 points in one cycle.
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