Lighthouse Audits

Lighthouse audits are a collection of checks performed across four categories: Performance, Accessibility, SEO and Best Practices. They are available for each Snapshot test, unless a test has been completed with partial results due to an error.

Performance Audits tab for a Snapshot showing a score out of 100 and listing audits in three categories: opportunities, diagnostics and passed audits.

Each audit category receives a score between 0 and 100, visible at the top of the audit section.

Audit structure#

All audit categories share the same structure, falling into the following groups:

  • Opportunities
  • Diagnostics
  • Passed audits

To ensure the best results, it's essential to focus on the Opportunities and Diagnostics, outlining possible improvements to a given page. Each audit item includes:

  • Title
  • Audit description
  • Measurement unit (optional)
  • Additional details (optional, e.g.: list of HTML elements)
Performance audit details showing a table with additional information about the audit item.

If an audit item features a table with more details, the table can be sorted by clicking on the column name.

Performance#

Performance audits are a set of web performance checks to ensure that a page can be accessed and interacted with. The Performance score is also known as the Performance Score. Higher grading implies (but doesn't guarantee) better performance.

Filter audits by metric affected#

To make it easy to focus on the critical metrics for user experience, you can filter the audits by performance metric they affect, such as:

  • Web Vitals: Largest Contentful Paint, Cumulative Layout Shift and Total Blocking Time
  • Web Vitals: First Contentful Paint

Accessibility#

Accessibility audits are a set of limited accessibility checks to ensure that a page meets selected accessibility criteria. Higher grading implies (but doesn't guarantee) better accessibility. Accessibility audits are limited and the use of dedicated, accessibility testing tools as well as manual testing is recommended.

SEO#

SEO audits are a set of limited checks to ensure the page is optimised for search engine results ranking. Higher grading implies (but doesn't guarantee) better search engine optimisation, which might also be affected by other factors, including Web Vitals performance.

Best Practices#

Best Practices audits highlight selected opportunities surrounding code health. Higher grading implies better code health, but due to limitations of this audit type, doesn't entirely guarantee it.

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