Google Set to Overhaul Lighthouse Audits by October 2025

Google is preparing a significant transformation of its Lighthouse tool, an update that will fundamentally alter how developers and SEO teams evaluate website performance. 

Beginning in June and concluding with the full launch in October 2025, the update will remove, merge, and restructure many of Lighthouse’s core audits. 

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The result is a new reporting format that aligns with Chrome DevTools, promising consistency but also forcing immediate adjustments across the industry.

Lighthouse has long been central to web diagnostics, used by engineers, marketers, and product teams to improve speed, usability, and technical SEO. Now, the framework behind those insights is changing.

What’s Changing and Why It Matters

The upcoming overhaul stems from Google’s decision to align Lighthouse with Chrome DevTools. 

Instead of maintaining two separate systems, Google will unify how audits are labeled, structured, and grouped. This consolidation will eliminate legacy audits and reorganize the rest into broader “insights,” reflecting Chrome DevTools’ more compact structure.

Barry Pollard, an engineer on Google’s Chrome team, confirmed the shift is designed to streamline reporting and reduce confusion for developers using multiple tools. But it won’t be seamless. 

Existing tools, workflows, and automated scripts that depend on specific Lighthouse audit names or formats will stop working unless they’re updated.

This change doesn’t just tweak performance scores. It rewrites how issues are categorized, interpreted, and communicated across development teams.

Merging, Retiring, and Reorganizing Audits+

The update breaks Lighthouse audits into three categories of change:

Merged and Renamed Audits

Many related tests are being bundled into new umbrella audits. For example:

• Layout shifts, unsized images, and non-composited animations are now grouped under “CLS Culprits Insight.”
• Image optimization audits will appear together under “Image Delivery Insight.”

This grouping removes the option to view or disable these checks individually. Developers can either include the full insight or exclude it entirely.

Audit Removals

Google is also removing a series of audits it considers obsolete, redundant, or unhelpful:

• First Meaningful Paint (replaced by more accurate metrics)
• No Document Write, Uses Passive Event Listeners, Uses Rel Preload

• Third-Party Facades, Offscreen Images

According to Google, these audits caused more noise than value in modern development environments and often flagged issues that didn’t reflect actual performance concerns.

New Audit Presentation Format

Lighthouse reports will now present results in two distinct sections:

• Insights: These are the new, bundled audits.
• Diagnostics: These are existing individual audits that remain unchanged.

This distinction is meant to reflect the dual structure used in Chrome DevTools, making it easier to interpret findings across both tools.

Key Timeline: When These Changes Take Effect

Google has laid out a structured timeline for the rollout:

• Available Now: JSON output from Lighthouse already includes the new insights structure for early testing.
• May/June 2025 (Chrome 137): Lighthouse v12.6 will include a toggle allowing users to preview the updated audit layout while still accessing the old format.
• June 2025: Lighthouse v12.7 will set the new format as default.
• October 2025: Version 13 will fully retire the legacy audits. The new insights structure becomes permanent.

These changes will also roll out to PageSpeed Insights and other related tools, further reinforcing the move across the entire performance testing ecosystem.

Immediate Implications for Developers and SEO Teams

This update will break compatibility with many existing systems. Teams using Lighthouse for continuous integration, automated testing, or client-facing reports will need to act quickly.

Here’s what to do now:

• Test Early: Use Lighthouse v12.6’s toggle feature to see how the new insights affect your reports.
• Update Scripts: Audit names and structures are changing. Any script that parses JSON output, tracks specific audits, or monitors performance over time must be revised.
• Revise Internal Dashboards: Reporting platforms that use Lighthouse data—especially client-facing SEO or performance scoreboards—will show discrepancies if left unchanged.
• Recalibrate Metrics: Since merged audits bundle issues, scores may rise or fall even if a site’s underlying performance hasn’t changed. Teams need to reset performance benchmarks accordingly.

Google’s team has acknowledged that while the goal is clarity and efficiency, the short-term effect will be disruption. Organizations that rely heavily on Lighthouse will feel that impact unless they adapt early.

Why This Update Signals a Strategic Shift

Lighthouse has always been a technical tool, but over the years, it has evolved into a foundational part of how websites are maintained, ranked, and marketed. 

By overhauling it, Google is signaling that the future of web performance testing is integrated, automated, and less reliant on fragmented insights.

The tighter alignment with Chrome DevTools also suggests a broader move toward unifying diagnostics within the Chrome ecosystem, allowing for more streamlined developer workflows.

Still, this is not a minor version update. It fundamentally alters how performance issues are identified, displayed, and prioritized. And for many teams, it means rethinking how they manage performance and communicate results to clients and stakeholders.

Looking Ahead

Google says documentation for the new audit structure will be available on developer.chrome.com before October. 

The company will also keep documentation for older versions available for teams still using previous Lighthouse builds.

A discussion thread has been opened on GitHub where developers can post questions, concerns, or feedback as they test the changes.

For those who want to get ahead, now is the time to update workflows and prepare for the new era of Lighthouse testing.

Key Takeaways

• Lighthouse audits are being permanently restructured in October 2025.
• Merging audits means individual test toggling will no longer be possible.
• Several older audits are being retired due to redundancy or inaccuracy.
• Existing scripts, CI tools, and dashboards must be updated to stay compatible.
• Performance scores may change even if your site doesn’t—due to how data is grouped.