Lighthouse

Lighthouse is a free, open-source tool for auditing web pages, best suited to web developers who want concrete improvement guidance. Its range of ways to run audits is useful, but the Chrome extension’s limits and the CLI’s software requirements make workflow choice important.

Overview

Give Lighthouse a URL and it runs audits, then produces a report with results and references explaining why checks matter and how to address failures. That context makes findings more actionable than a score alone, particularly for developers deciding what to fix.

It can audit public pages and pages that require authentication, but not through every workflow. DevTools can handle authenticated pages and local sites; the Chrome extension cannot. The extension is therefore a poor fit when those targets are part of the work.

Key features

Audits and reports

Lighthouse covers performance, accessibility, SEO, and best practices. Performance audits use modern metrics and provide insights. Reports can be generated as JSON or HTML, while the CLI also supports CSV output. These formats suit both direct review and workflows that process audit data.

Run options and customization

Run Lighthouse in Chrome DevTools, from the command line, as a Node module, or through a web UI without installation. Stack packs provide platform-specific recommendations, and plugins let domain experts add audits and report categories. The variety serves both quick checks and tailored workflows, though CLI and Node use require Google Chrome installed and Node 22 (LTS) or later.

Regression checks and sharing

Lighthouse can be integrated into continuous integration systems, and Lighthouse CI can help prevent site regressions. Reports can be viewed online and shared through Lighthouse Viewer using report JSON; the documentation also describes sharing them as secret GitHub Gists. WebPageTest can produce Lighthouse reports alongside its analysis, while HTTPArchive stores Lighthouse results in BigQuery.

On its first CLI run, Lighthouse asks whether it may anonymously report runtime exceptions. Opting out does not affect use. The project is open source and welcomes repository contributions.

Pricing

Lighthouse is free and open source. Its Lighthouse plan costs nothing and includes on-page audits and API access. There is no free trial because the tool itself is free; the stated plan has no listed usage quota or seat cap.

Platforms

Lighthouse is available through an API, extension, Linux, macOS, web, and Windows. DevTools, CLI, Node, and web UI give developers different ways to run it, but CLI and Node require both Chrome and Node 22 (LTS) or later. The extension cannot test local or authenticated pages, unlike DevTools.

Who it's for

Lighthouse is a strong fit for web developers who want performance, accessibility, SEO, and best-practice guidance, especially when they need reports or CI regression checks. It is less suitable for someone who needs the browser extension to audit local or authenticated pages, or who cannot meet the CLI and Node requirements.

Pros and cons

• Pros: Multiple run options let developers choose between DevTools, CLI, Node, and a web UI without installation.
• Pros: Explanatory audit reports and several export formats help turn findings into fixes or downstream data.
• Pros: CI integration and Lighthouse CI support regression prevention.
• Cons: The extension cannot audit local or authenticated pages, narrowing its usefulness for those targets.
• Cons: CLI and Node workflows require Chrome and Node 22 (LTS) or later.

Alternatives

For a broader category comparison, browse SEO Audit Software.

• Open SEO Crawler is a free, MIT-licensed self-hosted option with unlimited URLs and no account, API key, or per-URL billing; choose it when those crawling terms matter more than Lighthouse’s page-quality audits.
• A1 Website Analyzer has a free mode that continues after a 30-day evaluation period, with 500 page URLs per website and 500 imported URLs; choose it if that capped free mode fits your needs.
• Beam Us Up is a free crawler with no limits stated; choose it if you want that alternative.
• Checkbot has a free, ad-supported Basic plan with 100 URLs per crawl and unlimited crawls and sites; choose it if those crawl limits work for you.
• Crab is free and open source, with no URL limits or subscriptions; choose it if those terms suit your use.
• FreeCrawl offers free plans with unlimited URLs; choose it if you want that alternative.
• Greenflare is free and open source under GPLv3+; choose it if that option suits your needs.
• Netpeak Spider has a free plan with 500 URLs, 5 threads, and 2 devices per user on Windows and macOS; choose it if those limits and platforms fit.

Verdict

Choose Lighthouse if you are a web developer who wants free, open-source audits with explanatory reports and a path to CI regression checks. Look elsewhere if your workflow depends on the Chrome extension for local or authenticated pages, or if the Chrome and Node requirements make CLI or Node use impractical.