v151 · navigation · performance
Timing Comparison
Fire rapid navigations to the same hash vs. unique hashes and compare clicks vs hashchange events. This demonstrates the pre-existing hash dedup behavior (setting the same hash is always a no-op). Chrome 151 extends similar dedup logic to in-flight document navigations — which this page explains but cannot fully exercise without a slow server-side document.
What this measures vs. what Chrome 151 adds
This page measures: hash navigation dedup (pre-existing). Setting location.hash to the same value is a no-op in all browsers.
Chrome 151 adds: dedup of document navigations — if a full page navigation to URL X is still loading and a second request to the same X fires, the second is dropped. This prevents wasted bandwidth and flicker from rapid clicks on slow-loading pages.
For duplicate hash navigations, the ratio should be near 0 (pre-existing: same hash = no-op). For unique hashes, every click fires a hashchange. The Chrome 151 feature extends this concept to in-flight document navigations.