Release Notes

Release notes and minor bug fixes will be posted here.

Version 5

Lighthouse (which powers PageSpeed Insights) released v4.1 on January 31, 2019. Information on changes can be found here: Lighthouse 4.1 Release Notes

v5 of the PageSpeed Insights API was released in November 2018. It now uses Lighthouse as its analysis engine and also incorporates field data provided by the Chrome User Experience Report (CrUX). v5 of the API will now provide CrUX data and all of the Lighthouse audits. Previous versions of the PSI API will be deprecated in six months.

Version 4

v4 of the PageSpeed Insights API was released in January 2018. It adds a speed score based on Chrome User Experience Report and refines the original PSI score as a new optimization score which mainly focuses on the relative headroom to improve.

Version 2

v2 of the PageSpeed Insights API was released in January 2015. It adds support for rule groups, such as 'SPEED' or 'USABILITY'.

Updates after release:

  • Result category was added on May 12th, 2017.
  • Render engine was switched from Webkit to Blink on February 2nd, 2017.
  • Image optimization library was switched to use the one in mod_pagespeed on December 12th, 2016.
  • The app-install interstitial rule was removed from score compuation in both API versions on August 23th, 2016. The rule was removed completely on November 1st, 2016.

Deprecated. Will close on Jun 2018.

Version 1

The initial version of the API. This release includes support for localization in 40 languages.

On October 29, 2013, the ruleScore field, which has been deprecated in PageSpeed Insights for over a year, was removed from the API. We recommend that clients use the ruleImpact field instead.