INP Radar

Live INP value, main-thread radar and event log for the current page, in a side panel.

INP Radar shows when a page's main thread is blocked, live, in Chrome's side panel. A click can get a poor INP without doing anything slow itself. If a timer or a tracking script is blocking the main thread when the click lands, the click has to wait, and that wait counts as input delay. A single test click usually misses those blocks, so the problem is easy to overlook. Open any page and watch: • Radar and heartbeat trace: background work shows up as spikes, often on a steady beat. • INP breakdown: input delay, processing and presentation, with the target element. • Event log: every interaction of 16 ms or more. Use it to time a DevTools trace: record across a spike to find the blocking work, or wait until the page is idle, then click to measure the interaction on its own. Try it on the demo page: https://push-based.github.io/inp-radar/demo/ Nothing leaves your browser. Open source: https://github.com/push-based/inp-radar