Non-passive scroll listenerNon-passive scroll listener

Why it matters

The browser waits for a touch or wheel listener before every scroll frame unless it is passive (Lighthouse: does not use passive listeners to improve scrolling performance).

Fix

Pass { passive: true } when the handler never calls preventDefault().

Credit

• GC

  From Google Chrome

  Lighthouse recommends passive listeners so touch and wheel handlers do not block scrolling.

References

• Use passive listeners to improve scrolling performanceChrome for Developers
• EventTarget: addEventListener() methodMDN Web Docs

See it

Related rules

• bp/unload-listenerunload listener