Performance Guide
Core Web Vitals Guide 2025
Optimize LCP, INP, and CLS for better performance and higher rankings.
LCP
Loading performance
< 2.5s
INP
Interactivity
< 200ms
CLS
Visual stability
< 0.1
Why Core Web Vitals Matter
+24%
Lower bounce rates with fast pages
53%
Users abandon pages taking >3 seconds
Core Web Vitals are a direct Google ranking factor since 2021. Poor scores can hurt your visibility.
LCP - Largest Contentful Paint
LCP measures how long it takes for the largest content element (image or text block) to become visible in the viewport.
Good
< 2.5s
Needs Improvement
2.5s - 4s
Poor
> 4s
How to optimize LCP
Use a fast, reliable hosting with CDN
Optimize and lazy-load images (WebP, AVIF)
Minimize render-blocking CSS and JavaScript
Preload critical resources (fonts, hero image)
INP - Interaction to Next Paint
New in 2024: INP replaced FID (First Input Delay) as the official interactivity metric in March 2024.
INP measures the time from when a user interacts (click, tap, keyboard) until the browser shows a visual response.
Good
< 200ms
Needs Improvement
200-500ms
Poor
> 500ms
How to optimize INP
Break up long JavaScript tasks (< 50ms)
Use web workers for heavy computations
Defer non-critical JavaScript
Optimize event handlers and callbacks
CLS - Cumulative Layout Shift
CLS measures unexpected layout shifts during page loading. A high CLS means elements move around, frustrating users.
Good
< 0.1
Needs Improvement
0.1 - 0.25
Poor
> 0.25
Common causes of CLS
Images without dimensions
Ads and embeds without reserved space
Dynamically injected content
Web fonts causing FOIT/FOUT
How to fix CLS
Always set width and height on images
Reserve space for ads and embeds
Avoid inserting content above existing content
Use font-display: swap for web fonts