RUM update: lux.js v4.1.0

8 April 2025 (UTC)

We have released version 4.1 of lux.js today which brings Long Animation Frame support to SpeedCurve RUM.

New features

• Long Animation Frame (LoAF) data is now collected, including script attribution for INP.

Improvements

• LCP, CLS, and INP are now calculated right before the beacon is sent rather than when events are received.