INP Test Page

This page demonstrates poor Interaction to Next Paint (INP) with heavy JavaScript execution on user interactions.

Expected INP: > 500ms (Poor)

Price Calculator

Calculate total cost with tax and shipping. Each button click triggers expensive backend calculations.

0
Price includes tax and shipping calculations

Product Memory Game

Match product pairs to win discounts! Each click triggers heavy inventory processing.

Match all pairs to unlock 10% discount!

Laptop Configurator

Configure your perfect laptop. Each selection triggers complex compatibility checks.

Total: $0

Technical Support

Get help with your tech questions. Each message triggers comprehensive database searches.

Understanding INP Issues

Interaction to Next Paint (INP) measures responsiveness. Pages should strive to have an INP of 200 milliseconds or less.

Common causes of poor INP:

  • Long JavaScript tasks blocking the main thread
  • Large DOM size and complex DOM updates
  • Excessive event handlers
  • Heavy computations in response to user input

This page demonstrates:

  • Heavy calculations on every button click
  • Complex DOM manipulations
  • Synchronous operations that block the main thread
  • Expensive validation on every keystroke