<b>Test on mobile first — that's the score that counts</b>

<b>Test on mobile first — that's the score that counts</b>

A quiet truth behind Core Web Vitals: Google primarily judges the <b>mobile</b> experience, because most searches happen on phones. So if you only ever test on your desktop, you're checking the version that matters least.

Mobile is harder on every metric: weaker processors strain INP (Interaction to Next Paint), slower networks stretch LCP (Largest Contentful Paint), and small screens make layout shifts feel worse for CLS (Cumulative Layout Shift).

Think of it like packing for the tougher hike, not the easy stroll — prepare for the harder trip and the easy one takes care of itself.

How to test the right view:
— In PageSpeed Insights, click the <b>Mobile</b> tab before reading scores
— In DevTools, toggle the device-toolbar (phone icon) and pick a mid-range phone
— Add throttling so it mimics a real cellular connection

<b>Try this:</b> Run your most important page on the Mobile tab and treat <i>those</i> numbers as your real grade. If mobile passes, you've cleared the hardest bar.