demo · v139
Birthday Collision Simulator
Why random port picking on Windows isn't just “more secure” — it changes the collision probability curve. Sweep the connections-per-second knob; watch how fast you'd hit a previously-reused port in the deterministic vs random strategies.
100
120
first collision at
—
total collisions / 60s
—
peak in-flight
—
busy-pick share
Adjust a control or run the simulation to compare the allocation strategies.
ChromeStatus describes this as a Windows-only networking change, not a JavaScript API. The old
deterministic allocation made the next source port predictable enough for a site to infer how
many TCP connections another tab opened. Randomized allocation on supported Windows builds hides
that counter, while the collision model explains why the rollout is gated to versions with safer
port reuse behavior.