Google Lighthouse Performance Audit Revamp: Key Changes for SEO

Google Lighthouse Performance Audits Get a Major Overhaul

Google is revamping its Lighthouse performance audits to match the insights in Chrome DevTools' Performance panel. This significant update will change how performance data is presented and organized, impacting how SEO professionals use Lighthouse for website optimization.

Consolidating Google's Performance Tools

This update streamlines Google's performance tools. Barry Pollard from Google's Chrome team explains,

“We’re updating the audits in Lighthouse to be based on the same Insights we recently launched in the Performance panel of Chrome DevTools. This will help align the two tools but will be a breaking change.”

You can learn more in Google's official announcement.

Key Changes to Lighthouse Audits

The changes fall into three categories:

• Merging and Renaming: Several audits are being combined. For example, "layout shifts," "non-composited animations," and "unsized images" will merge into "cls culprits insight." Image optimization audits will combine into "image-delivery-insight." This means you can no longer disable parts of these combined audits individually.
• Removals: Some audits are being removed entirely, including First Meaningful Paint (replaced by Largest Contentful Paint), No Document Write, Offscreen Images, Uses Passive Event Listeners, Uses Rel Preload, and Third-Party Facades. These removals reflect improvements in browser technology and changes in best practices.
• New Organization: New insight audits will appear under "Insights" in reports. Unchanged audits will remain under "Diagnostics."

Timeline and Preparation

The rollout will occur in stages. The new insights are already available in the Lighthouse JSON output. A toggle in Lighthouse 12.6 (May/June 2025 in Chrome 137) will let you switch between old and new views. Lighthouse 12.7 (June) will use the new insights by default. Lighthouse 13 (October) will remove the old audit data completely.

To prepare, use the toggle in Lighthouse 12.6.0 to familiarize yourself with the new reports. Update any systems using Lighthouse data and any reports or analyses referencing specific audit names. Communicate these changes to stakeholders.

Impact on SEO and Website Optimization

Google continues to prioritize page experience and Core Web Vitals. While the underlying metrics remain the same, this reorganization changes how you identify and address performance issues. The merged audits may offer a more holistic view of related issues, simplifying prioritization. However, teams with custom tools based on specific Lighthouse audits will need to adapt.

Additional Resources and Feedback

Google will publish documentation on developer.chrome.com before the October change. Older documentation will remain available for users of previous Lighthouse versions. A GitHub discussion is open for feedback and questions.