Lighthouse Score Interpreter
Paste a Lighthouse JSON report (downloaded from DevTools, PageSpeed Insights, or a CI run) and get a plain-English summary of every score, with the top opportunities ranked by potential impact. Useful when sharing perf reports with non-developers or triaging which fix to do first.
How to use the Lighthouse Score Interpreter
Run Lighthouse in Chrome DevTools (Lighthouse panel → Generate report → Save as JSON), or download the JSON from pagespeed.web.dev. Paste it here. The interpreter shows each category score, lists the top opportunities sorted by potential savings, and explains each metric in plain English.
Reading a Lighthouse report
A Lighthouse run produces a dense JSON report — dozens of audits, weighted category scores, and opportunities measured in milliseconds — that is hard to act on directly, and harder still to share with someone who does not read Lighthouse output for a living. The signal you want is buried: which few fixes will move the score most, and what each metric actually means.
This reads a pasted Lighthouse JSON report (from DevTools, PageSpeed Insights, or a CI run) and turns it into a plain-English summary — each category score, the top opportunities ranked by potential savings, and a readable note on every metric. It interprets a real report’s numbers; to understand what the Core Web Vitals behind those numbers mean and their pass/fail thresholds, see the Core Web Vitals explainer.
Common use cases
- Triage fixes — see which opportunities save the most time and do those first.
- Share with non-devs — turn a raw report into a summary a stakeholder can read.
- Track CI runs — interpret the JSON a Lighthouse CI step produces.
- Understand a score — learn why a category landed where it did.
- Compare runs — read two reports’ summaries to see what changed.