---
title: "Lighthouse Report Viewer - Analyze JSON Reports Online Free · Unlighthouse"
canonical_url: "https://unlighthouse.dev/tools/lighthouse-report-viewer"
last_updated: "2026-06-30T08:48:12.818Z"
meta:
  description: "Free Lighthouse JSON viewer and report analyzer. Upload or paste Lighthouse JSON to view scores, Core Web Vitals, and audit details. Works with PageSpeed Insights API output and Chrome DevTools exports."
  "og:description": "Free Lighthouse JSON viewer and report analyzer. Upload or paste Lighthouse JSON to view scores, Core Web Vitals, and audit details. Works with PageSpeed Insights API output and Chrome DevTools exports."
  "og:title": "Lighthouse Report Viewer - Analyze JSON Reports Online Free · Unlighthouse"
---

</h1>

```

Unlighthouse on GitHub

# **Lighthouse Report **Viewer

Upload or paste a Lighthouse JSON report to analyze scores, Core Web Vitals, and audits interactively.

**Report Viewer**

**Drop your Lighthouse JSON here **

or click to browse files

**How to export Lighthouse JSON: **

1. Open Chrome DevTools (F12)
2. Go to the Lighthouse tab
3. Run an audit
4. Click "Export" → "Save as JSON"

## **How to Read a Lighthouse Report **

Lighthouse audits your page across five categories. Each category receives a score from 0-100, with **90+** being good, **50-89** needing improvement, and **below 50** being poor.

Focus on **Performance** first—it directly impacts user experience and SEO. Within Performance, prioritize the **Opportunities** section, which shows specific improvements with estimated savings.

### **Category Quick Reference **

**Performance **

Loading speed, interactivity, visual stability

**Accessibility **

Screen readers, contrast, keyboard navigation

**Best Practices **

Security, modern APIs, image optimization

**SEO **

Meta tags, crawlability, mobile-friendliness

**PWA **

Installability, offline support, app-like experience

## **Pro Tips for Improving Your Score **

### **Start with Quick Wins **

Focus on opportunities with the highest estimated savings first. Image optimization and unused code are often easy fixes.

### **Test Multiple Times **

Lighthouse scores can vary between runs. Test 3-5 times and average the results for a more accurate picture.

### **Prioritize Core Web Vitals **

LCP, CLS, and INP directly affect search rankings. Focus on getting these green before other optimizations.

### **Test on Mobile **

Google uses mobile-first indexing. Your mobile score matters more than desktop for SEO.

### **Check Field Data **

Lab data (Lighthouse) is synthetic. Check Chrome UX Report for real-world user experience data.

### **Don't Chase 100 **

Diminishing returns after 90. A score of 90+ is excellent—spend time on features, not micro-optimizations.

**Was this tool helpful? **

Your feedback helps us improve

## **Frequently Asked Questions **

<details>

<summary>**01**### **How do I view a Lighthouse JSON report?**

</summary>

Upload your Lighthouse JSON file by dragging and dropping it onto this page, clicking the upload area, or pasting the JSON content directly. The viewer will parse and display your performance scores, metrics, and audit results in an interactive format.

</details>

<details>

<summary>**02**### **How do I export a Lighthouse report as JSON?**

</summary>

In Chrome DevTools, run a Lighthouse audit then click "Save as JSON" in the report header. From the command line, run: npx lighthouse <url> --output=json --output-path=report.json. The PageSpeed Insights API also returns JSON that works with this viewer.

</details>

<details>

<summary>**03**### **What information does a Lighthouse JSON report contain?**

</summary>

Lighthouse reports include performance scores (0-100), Core Web Vitals metrics (LCP, CLS, TBT), detailed audit results for performance, accessibility, best practices, SEO, and PWA categories, plus timing data, screenshots, and optimization opportunities.

</details>

<details>

<summary>**04**### **Can I compare multiple Lighthouse reports?**

</summary>

This viewer shows one report at a time. For comparing reports over time, consider Lighthouse CI which stores historical data, or export multiple JSON reports and compare the metrics manually. The Unlighthouse CLI can scan your entire site and track changes.

</details>

<details>

<summary>**05**### **Why use a Lighthouse report viewer instead of the HTML report?**

</summary>

JSON reports are smaller, easier to store, and work better with automation. This viewer provides the same visual experience as HTML reports, with additional features like dark mode, better mobile support, and the ability to quickly inspect specific audits.

</details>

<details>

<summary>**06**### **Is this Lighthouse viewer free?**

</summary>

Yes, this Lighthouse JSON viewer is completely free with no signup required. Your report data stays in your browser and is never uploaded to any server. Use it as often as you need for viewing and analyzing Lighthouse reports.

</details>

<details>

<summary>**07**### **How do I view a Lighthouse report online?**

</summary>

Use this free Lighthouse report viewer to view reports online. Upload a JSON file, paste JSON content, or load a sample report. The viewer displays all scores, Core Web Vitals metrics, performance opportunities, and audit results in an interactive format—no installation required.

</details>

Explore more Lighthouse tools

[**Score Calculator **](https://unlighthouse.dev/tools/lighthouse-score-calculator) [** PageSpeed Insights **](https://unlighthouse.dev/tools/pagespeed-insights-performance) [** Learn Lighthouse **](https://unlighthouse.dev/learn-lighthouse) [** Core Web Vitals Guide **](https://unlighthouse.dev/learn-lighthouse/core-web-vitals) [** PSI vs Lighthouse **](https://unlighthouse.dev/learn-lighthouse/pagespeed-insights-vs-lighthouse)