RUM update: lux.js v306

19 March 2023 (UTC)

New features


  • Custom data is now only sent when it has been updated. This reduces beacon size and prevents unnecessary beacons from being sent.

Bug fixes

  • Calling LUX.init() will now reset FID between SPA page views. Previously the first FID value was recorded for all subsequent SPA page views. This will result in much fewer FID measurements on SPAs, and potentially affect the User Happiness score.
  • Element timing values in SPA pages are now relative to the most recent LUX.init call rather than relative to navigationStart.
  • Fixed a bug where pages with many user timing entries did not have their path or domain recorded.
  • Largest Contentful Paint is now measured as the time since activationStart, not navigationStart. This means LCP will be correctly recorded as zero for prerendered pages.