Redline runs the same stress on the actual hardware your users carry. It shows you exactly which subsystem will drop frames on a low-end phone, and which fix pays off there — instead of the fix that only felt faster on your machine.
Run a stress testYour dev machine is a best case. Run Redline on the cheapest phone you support and set CI budgets against that score, not against an M2 MacBook.
The CPU benchmark pushes mixed math until the thread blocks, so you can watch input latency emerge on real silicon — not guess at it from a flame chart.
The DOM/layout benchmark forces reflow on the device's own engine. If a deep component tree drops frames here, it drops frames in production.
The analysis references your real numbers and names concrete techniques — scheduler.yield(), contain, transform-only animations — so you can act immediately.