LCPLargest Contentful Paint
How long until the biggest thing on screen — usually a hero image or headline — actually renders. A heavy, unsized, render-blocking asset pushes this out.
Largest Contentful Paint: not measured yet.
Render stage
The number is the real render time of the element, from click to painted frame.
// click a button to see the code path
INPInteraction to Next Paint
When you click or tap, how long until the screen visibly responds. Heavy JavaScript on the main thread blocks the paint and makes the UI feel frozen.
Interaction to Next Paint: not measured yet.
Interaction stage
Counter: 0
The bad button runs a ~350 ms synchronous task before the UI can repaint — that lag is your INP.
// click a button to see the code path
CLSCumulative Layout Shift
How much the page jumps around as it loads. Content injected without reserved space shoves everything below it — the classic "I tapped the wrong button" moment.
Cumulative Layout Shift: not measured yet.
Layout stage
Watch the grey lines jump. The score is the real shift geometry run through the CLS formula (impact × distance), scoped to this panel.
// click a button to see the code path