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Chrome Lighthouse

PageSpeed Insights (PSI) reports on the user experience of a page on both mobile and desktop devices, and provides suggestions on how that page may be improved.
Analytics

What is Chrome Lighthouse?

Chrome Lighthouse audits a URL that a person or another tool supplies. It opens the page in Chrome, runs a set of checks, and returns a report. The standard audit areas cover performance, accessibility, SEO, and browser best practices. Lighthouse does not maintain a discovery queue or build a web index.

The same software can run in Chrome DevTools, from the command line, through a Node module, or inside PageSpeed Insights. It can audit a public page or an authenticated page when the person running it has access. That range of environments is why Lighthouse traffic does not come from one central crawler service.

PageSpeed Insights uses Lighthouse for its controlled lab load. Its field section is different: Google obtains that historical, real-user data from the Chrome User Experience Report. A Lighthouse request visible in server logs contributes to the lab audit, not to every metric shown in the PageSpeed report.

A run loads the requested document and the assets needed to render it. The network user agent can be emulated or supplied by the runner; some configurations append Chrome-Lighthouse, and the report records the value used. Lighthouse does not use the fetched page for Google indexing, AI search, or language-model training.

Not relevant for AI search

Is Chrome Lighthouse relevant for AI search?

No. Chrome Lighthouse is not part of AI search or training, so allowing or blocking it does not change your AI visibility.

Chrome Lighthouse collects data about pages for analysis and reports. The data describes your site rather than promoting it, and nothing it gathers goes into a search index or an AI model.

How to handle Chrome Lighthouse

Allow the load when a developer, customer, or monitoring job is intentionally testing the public page. If PageSpeed Insights is blocked, its lab audit can fail even though an authorized developer may still run Lighthouse locally.

There is no universal Lighthouse token for a dependable robots.txt rule. User-run installations can change the network user agent, and Lighthouse can operate behind authentication. Protect private pages with authentication or a network allowlist. A filter for Chrome-Lighthouse can catch some hosted tests, but it will neither cover every Lighthouse run nor block Googlebot.

Examples

  • A developer submits a slow product page to PageSpeed Insights and matches the report's fetch time with the burst of page and asset requests in the server log.
  • A release team keeps its staging site private but runs Lighthouse from an authenticated CI job, without opening the site to public PageSpeed tests.

Frequently asked questions about Chrome Lighthouse

Learn about AI visibility monitoring and how Promptwatch helps your brand succeed in AI search.

No. A user or tool supplies the URL to audit. Lighthouse does not crawl outward to build a general index.

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