v10.0.0

Full Changelog
Release article

We expect this release to ship in the DevTools of Chrome 112, and to PageSpeed Insights within 2 weeks.

New Contributors

Thanks to our new contributors 👽🐷🐰🐯🐻!

• Alex N. Jose @alexnj
• Alexandra White @heyawhite
• Amanda @apettenati
• Andrew Gutekanst @Andoryuuta
• Christopher Holder @ChristopherPHolder
• Dongkyun Yu (Steve) @hackurity01
• Floris @FMJansen
• Gabe @MrBrain295
• ghost_32 @k99sharma
• Littleton Riggins @TripleEquals
• lowkeyAngry @lowkeyAngry
• Michael McMahon @TechnologyClassroom
• Shogo Hida @shogohida
• Stoyan @stoyan
• Yang Guo @hashseed

Notable Changes

Performance Score Changes

In the 8.0 release, we described TTI's waning role, and today we have the followup. Time to Interactive (TTI) no longer contributes to the performance score and is not displayed in the report. However, it is still accessible in the Lighthouse result JSON.

Without TTI, the weighting of Cumulative Layout Shift (CLS) has increased from 15% to 25%. See the docs for a complete breakdown of how the Performance score is calculated in 10.0, or play with the scoring calculator.

Types for the Node package

Lighthouse now includes type declarations! Our example TypeScript recipe demonstrates how to achieve proper type safety with Lighthouse.

Third-party Entity classification

Since Lighthouse 5.3, the community-driven third-party-web dataset has been used to summarize how every third-party found on a page contributes to the total JavaScript blocking time, via the third-party-summary audit. With Lighthouse 10.0, we are adding a new property to the JSON result (entities) to make further use of this dataset. Every origin encountered on a page is now classified as first-party or third-party within entities. In 10.0, this classification is used to power the existing third-party filter checkbox.

In a future version of Lighthouse, this will be used to group the table items of every audit based on the entity it originated from, and aggregate the impact of items from that specific entity.

🆕 New Audits

Back/forward cache

The Back/forward cache (bfcache for short) is a browser optimization that serves pages from fully serialized snapshots when navigating back or forwards in session history. There are over 100 different reasons why a page may not be eligible for this optimization, so to assist developers Lighthouse now attempts to trigger a bfcache response and will list anything that prevented the browser from using the bfcache. #14465

For more on bfcache, see the web.dev article.

Note: This audit initially will not be available for PageSpeed Insights.

Preventing pasting to inputs

The audit password-inputs-can-be-pasted-into is now paste-preventing-inputs. This audit's logic works just as before, but rather than just considering [type=password] inputs, it now fails if any non-readonly input element prevents the user from pasting. #14313

Lighthouse documentation is now on developer.chrome.com

Our documentation is no longer hosted on web.dev. For the most up to date audit docs, please go to developer.chrome.com/docs/lighthouse/

💥 Breaking changes

Under the hood, Lighthouse now uses the new user-flow supporting infrastructure by default, even for traditional navigation runs. You can opt out of this by: in the CLI, use --legacy-navigation; in DevTools: check “Legacy Navigation” in the settings menu. If you have a use case that necessitates this escape hatch, please file an issue. We plan to remove this legacy path in 11.0.

For Lighthouse result JSON (LHR) users

Page URLs on the Lighthouse Result

Until now, there were two URL fields to describe a Lighthouse run:

• requestedUrl: the url given by the users, which Lighthouse instructs Chrome to navigate to
• finalUrl: the url after any server-initiated HTTP and JS-initiated redirects

This taxonomy cannot account for more complex scenarios, such as JS-initiated redirects, usage of the History API or soft-navigations. They were also ill-defined for timespan and snapshot modes. To account for that, Lighthouse 10.0 now has these URL fields:

• (changed) requestedUrl: The URL that Lighthouse initially navigated to before redirects. This is the same as it was before for navigation mode, but now it will be undefined in timespan/snapshot.
• (new) mainDocumentUrl: The URL of the last document requested during a navigation. It does not account for soft navigations or history API events made after the page loads. It is only available in navigation mode, and will be undefined in timespan and snapshot modes.
• (new) finalDisplayedUrl: The URL displayed in the browser combobox at the end of a Lighthouse run. It accounts for soft navigations and history API events. Available in navigation, timespan, and snapshot modes.
• (deprecated) finalUrl: Same value as mainDocumentUrl.

Audit changes

• password-inputs-can-be-pasted-into -> paste-preventing-inputs
• preload-lcp-image -> prioritize-lcp-image
• third-party-summary no longer uses a link value for item.entity, instead uses a raw text value
• full-page-screenshot is no longer an audit, instead it is stored at lhr.fullPageScreenshot. To suppress collection of the full-page screenshot in the CLI, you must migrate from --skip-audits full-page-screenshot to --disable-full-page-screenshot.

For Node users

• Node 14 is no longer supported, the minimum is now Node 16
• In case you import paths within the lighthouse node package: lighthouse-core/ and lighthouse-cli/ folders are now simply core/ and cli/
• Converted from CommonJS to ES modules. You can still use lighthouse in CommonJS by using an dynamic import: await import('lighthouse'). For access to just the lighthouse function in CommonJS, you can also use require('lighthouse/core/index.cjs')
• The CSV output for Lighthouse is much more useful now. Consult the PR for an example of the new format
• LHError is now LighthouseError. If you are attempting to catch an error thrown by Lighthouse, be sure to account for this!

Node API changes

The lighthouse function now has better integration with Puppeteer. Use lighthouse(url, flags, config, page) to run Lighthouse, passing an existing Puppeteer.Page handle as page.

The user flow api has moved to the top level node entrypoint and can be imported with import {startFlow} from 'lighthouse'.

New flow.startNavigation() and flow.endNavigation() functions let you define a user triggered navigation without any callback function. See the user flow docs for an example.

To change settings for a single user flow step, define the settings overrides on the toplevel flags options flow.snapshot({skipAduits: ['uses-http2']}) instead of on the settingsOverride property.

To give a flow step a custom name, use flow.snapshot({name: 'Custom name'}). Previously this was done via stepName.

For Lighthouse customization (custom config, gatherers, audits)

• To work in Lighthouse 10.0, custom gatherers will need to implement the new Gatherer interface (an example). Otherwise, they will only work in legacy navigation mode and older versions of Lighthouse
• Lighthouse cannot use passes to load the page multiple times in navigation mode anymore. If you need to load the page multiple times, we recommend using a user flow. See our config docs for instructions on how to convert to the new config format
• The ScriptElements artifact is now Scripts, with a slightly different shape
• Audit.makeOpportunityDetails and Audit.makeTableDetails now accept an options object as the third parameter. This ends up being a breaking change for just Audit.makeOpportunityDetails.

Detailed changelog

Removed Audits

• [BREAKING] apple-touch-icon: remove audit (#14243)
• [BREAKING] vulnerable-libraries: remove audit (#14194)
• [BREAKING] full-page-screenshot: remove audit, move to top-level (#14657)

Core

• [BREAKING] scoring: rebalance perf metric weightings for v10 (#14667)
• [BREAKING] third-party-summary: change item.entity from link...

v9.6.8

Full Changelog

We expect this release to ship in the DevTools of Chrome 109, and to PageSpeed Insights within 2 weeks.

Core

• deprecations: use translated strings from devtools repo (#13961)
• network-request: backport rendererStartTime (#14481)

v9.6.7

Full Changelog

This is an npm-only release. We have no plans to release this specific version to DevTools or PSI, but the changes will be rolled up into the next release in those clients.

Core

• core(trace-elements): include LCP type in artifact (#14344)
• core: add priority to network-requests debug audit (#14340)

v9.6.6

Full Changelog

We expect this release to ship in the DevTools of Chrome 107, and to PageSpeed Insights within 2 weeks.

New Contributors

Thanks to our new contributor 👽🐷🐰🐯🐻!

• Steven @styfle

Core

• unsized-images: ignore non-network SVGs (#13737)

Deps

• upgrade csp-evaluator (#14281)

v9.6.5

Full Changelog

This is an npm-only release and affects only the raw JSON report. We have no plans to release this specific version to DevTools or PSI, but the changes will be rolled up into the next release in those clients.

Core

• core(network-requests): include starting timestamp as debug data (#14253)
• core: use trace time origin for main-thread-task time origin (#14252)

v9.6.4

Full Changelog

We expect this release to ship in the DevTools of Chrome 106, and to PageSpeed Insights within 2 weeks.

Deps

• lighthouse-stack-packs: upgrade to 1.8.2 (#14218)

Clients

• lr: expose listenForStatus (#14024)

Misc

• misc: keep scripts package.json in npm (#14239)

v9.6.3

Full Changelog

This is an npm-only release and affects only the raw JSON report. We have no plans to release this specific version to DevTools or PSI, but the changes will be rolled up into the next release in those clients.

Core

• network-requests: add frame and preload debug data (#14161)
• preload-lcp-image: enrich debugData (#14155)

v9.6.2

Full Changelog

We expect this release to ship in the DevTools of Chrome 104, and to PageSpeed Insights within 2 weeks.

Core

• driver: fix legacy runner hanging oopifs in some cases (#14074)

Report

• avoid really slow regexes for data urls (#13791)

Clients

• psi: expose the swapLocale types (#14062)

Tests

• smoke: fix ToT node id failures (#14077)
• devtools: sync web tests (#14061)

Misc

• build: fix lightrider report generator bundle (#14031)

v9.6.1

Full Changelog

We expect this release to ship in the DevTools of Chrome 103, and to PageSpeed Insights within 2 weeks.

Core

• fps: run at the end of timespan/snapshot (#13989)
• responsiveness: add element screenshot to INP diagnostic (#13984)
• responsiveness: add better INP fallback for old Chrome versions (#13985)

Report

• devtools: use absolute positioning for overlay (#13988)

Tests

• use origin-agent-cluster to actually test oopifs (#13777)

v9.6.0

Full Changelog

We expect this release to ship in the DevTools of Chrome 103, and to PageSpeed Insights within 2 weeks.

New Audits

• The new performance metric Interaction to Next Paint (INP) assesses responsiveness by measuring the latency of interactions throughout the page lifecycle. INP can be measured using Lighthouse timespan mode accessible through user flows or the new DevTools panel. (#13917)

Core

• extract BootupTime task summary methods (#13971)
• css-usage: fetch stylesheet contents immediately after discovery (#13887)
• installability-errors: add url scheme error (#13846)
• installable-manifest: always run InstallabilityErrors in legacy mode (#13622)
• responsiveness: use new EventTiming trace event format (#13979)
• responsiveness: use raw trace event (#13970)
• trace: use tracing-started event for frame tree info (#13913)
• trace: add PrePaint event, renamed from UpdateLayerTree (#13950)
• trace-processor: ignore navigationStart with falsy document url (#13848)
• resolve redirected script records (#13751)
• deprecations: drop compat for ConsoleMessages (#13893)
• deprecations: hard-code english strings (#13961)

Report

• hide disclaimer text in timespan (#13931)
• psi: stub out locale swapping (#13885)
• report: render notApplicable metrics with double dash (#13981)

Deps

• upgrade third-party-web (#13873)
• update to third-party-web 0.15.0 (#13804)
• axe-core: upgrade to 4.4.1 (#13814)
• js-library-detector: upgrade to 6.5.0 (#13969)
• lighthouse-stack-packs: upgrade to 1.8.1 (#13862)
• snyk: update snyk snapshot (#13823, #13880)
• lodash: use individual lodash modules to reduce bundle size (#13914)
• puppeteer: upgrade to 13.7.0 (#13657)

Tests

• upgrade devtools web tests deps, use python3 (#13782)
• update create-test-trace utility (#13942)
• rebaseline webtests (#13963)
• smoke: remove old chrome version checks (#13903)
• smoke: support full chrome version for pruning (#13896)