What is PageSpeed Insights?

PageSpeed Insights is a free tool from Google that analyzes a web page and shows:

---

#1. Loading speed

Broken down into scores for mobile and desktop, rated from 0 to 100. The higher the score, the better the optimization.

---

#2. Core Web Vitals

Shows the values of the metrics: LCP, FID (or its replacement, INP), CLS - and indicates whether they meet the targets.

---

#3. Recommendations

Detailed advice:

• which resources slow down loading,
• what can be compressed,
• where to remove unnecessary JavaScript,
• which images are oversized, etc.

---

#4. Two types of data:

• Field data (real users) - from Chrome reports;
• Lab data (emulation) - from Lighthouse, to test under controlled conditions.

---

In short, it's a tool that shows what's stopping your site from being fast, stable, and convenient, and how to fix it.