INP, or Interaction to Next Paint, is one of Google’s three Core Web Vitals: a measure of how responsive your site feels once someone actually starts using it. Poor INP scores are a sure sign of user frustration. This simulator allows you to experience the same kinds of delays that your users are feeling.
If your site feels sticky, sluggish, or slow to react, this is exactly the sort of problem I help teams diagnose and fix. Let’s talk!
ms – Needs Improvement
Mirrored output:
Hi there, I’m Harry Roberts. I am an award-winning Consultant Web Performance Engineer, designer, developer, writer, and speaker from the UK. I write, Tweet, speak, and share code about measuring and improving site-speed. You should hire me.
Web Day Out: Brighton (England), March 2026
I help teams achieve class-leading web performance, providing consultancy, guidance, and hands-on expertise.
I specialise in tackling complex, large-scale projects where speed, scalability, and reliability are critical to success.