Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesThe latest release listed for Google Lighthouse is v13.5.0, dated September 18, 2026. For most users, the biggest recent change is Lighthouse 13’s shift from separate legacy performance audits to consolidated Performance Insights. Google says Lighthouse 13 did not change the performance score. A newer experimental Agentic Browsing category checks machine-interaction signals, but it is not a replacement performance score.
What’s new in the latest Lighthouse release?
Google’s Lighthouse releases page lists v13.5.0, published September 18, 2026. Its notable audit addition is Agent Resource Discovery (ARD). The release also lists response-header capture support, user-flow navigation abort handling, and changes to the llms.txt and WebMCP audits.
The release notes say the team expected v13.5.0 to ship in Chrome DevTools with Chrome 156 and in PageSpeed Insights within two weeks. That is a stated expectation, not confirmation that every surface has completed its rollout. The version available to you can depend on whether you use npm, DevTools, or PageSpeed Insights.
| Where you use Lighthouse | What to know |
|---|---|
| npm module or CLI | Install or check the package version directly; Lighthouse 13 requires Node.js 22.19 or later. |
| Chrome DevTools | The Lighthouse version is tied to the version and release channel of Chrome that embeds it. The v13.5.0 release notes anticipated Chrome 156. |
| PageSpeed Insights | It uses Lighthouse, but its rollout may not match the npm or DevTools version. The v13.5.0 notes anticipated availability within two weeks. |
| Chrome or Firefox extension | Google lists browser extensions as another way to access Lighthouse; check the extension’s version and release information rather than assuming it matches another surface. |
Release history also records v13.3.0 adding Agentic Browsing to the default configuration and v13.1.0 adding a Baseline compatibility audit. Neither should be confused with v13.5.0’s ARD audit.
#1 Best Overall
What changed in Lighthouse 13?
Lighthouse 13 reorganized performance diagnostics to align more closely with the insights in Chrome DevTools’ Performance panel. Several older audits were consolidated into new insight audits, and other audits were removed. Google’s Lighthouse 13 announcement says the change did not alter performance scoring: the score is based on metrics, while the audits affected by the update were non-scored.
Legacy audits consolidated into insights
| Older audit IDs | Consolidated or replacement insight |
|---|---|
layout-shifts, non-composited-animations, unsized-images |
cls-culprits-insight |
redirects, server-response-time, uses-text-compression |
document-latency-insight |
dom-size |
dom-size-insight |
duplicated-javascript |
duplicated-javascript-insight |
Audits removed without replacements
Lighthouse 13 also removed these audit IDs without replacing them with a new insight:
first-meaningful-paintfont-sizeno-document-writeoffscreen-imagespreload-fontsthird-party-facadesuses-passive-event-listenersuses-rel-preload
Google gives different reasons for the removals: some checks were no longer recommended, some were rarely actionable, and others could encourage changes that might hurt performance.
What teams should update
If a script, dashboard, or test suite reads Lighthouse JSON or depends on specific audit IDs, update it to handle the new insight IDs and missing audit data. Treat this as a diagnostics and report-structure migration, not a change to the performance-score calculation.
What is Agentic Browsing in Lighthouse?
Agentic Browsing is an experimental category of deterministic audits for signals that may help software agents discover and interact with a website. Google’s Agentic Browsing scoring guide describes checks that include accessibility-tree names and roles, layout stability, WebMCP tool registration, and whether an llms.txt file is present at the domain root.
Google’s June 2026 agent-ready toolkit announcement distinguishes discovery from interaction: Agentic Browsing is aimed at the interaction stage, complementing other ways agents may find websites.
How to interpret the results
Do not read Agentic Browsing as a conventional Lighthouse score out of 100. The category reports a fraction of readiness checks passed, individual audit statuses, and informational counts. It is experimental, so its findings are not an established ranking or proof that a site will work well with every agent.
Results can vary when JavaScript registers tools dynamically or when the page’s accessibility tree or layout changes during capture. A finding is best treated as a signal to investigate the relevant implementation, not a guarantee about real-world agent behavior.
Browser and WebMCP requirements
The documented Agentic Browsing category requires Chrome 150 or later. Its WebMCP audits have an extra condition: the site must register for the WebMCP origin trial. These are requirements for the documented category, not general prerequisites for running every Lighthouse audit.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Which Lighthouse version should you check?
Lighthouse can be accessed through Chrome DevTools, npm as a module or CLI, browser extensions for Chrome and Firefox, and PageSpeed Insights. These are related but distinct release surfaces: the Lighthouse version installed from npm is not necessarily the version embedded in your Chrome build or currently served by PageSpeed Insights.
- For local command-line runs: check the installed package version and use Node.js 22.19 or later for Lighthouse 13.
- For DevTools runs: check your Chrome version and release channel; embedded Lighthouse updates with Chrome rather than npm.
- For PageSpeed Insights: consult the service directly instead of assuming its rollout matches your local installation.
- For automation: pin or record the Lighthouse version used in each run so audit-ID changes can be distinguished from changes in the page being tested.
The Lighthouse CI release history shows that the CI companion tracks Lighthouse versions, making version awareness relevant to teams that automate audits.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
