Core Web Vitals Optimization Checklist
Complete checklist for passing Google's Core Web Vitals assessment. Covers LCP, CLS, and INP optimization with actionable items.
LCP
0/7Identify your LCP element
highUse Chrome DevTools or PageSpeed Insights to find your largest contentful element (usually hero image or heading)
Preload LCP image
highAdd <link rel="preload"> for your hero image to start loading it immediately
Optimize LCP image size
highCompress and serve appropriately sized images for each viewport
Use modern image formats
highConvert images to WebP or AVIF for smaller file sizes
Reduce server response time
mediumOptimize TTFB by using a CDN and caching
Remove render-blocking resources
highDefer non-critical CSS and JavaScript
Avoid lazy loading LCP element
mediumNever lazy load your above-the-fold hero image
CLS
0/7Set explicit dimensions on images
highAlways include width and height attributes on <img> tags
Reserve space for ads
highUse min-height or aspect-ratio CSS for ad containers
Reserve space for embeds
mediumSet dimensions for iframes, videos, and third-party embeds
Avoid inserting content above existing content
highDon't dynamically inject banners or notifications above the fold
Use transform for animations
mediumAnimate with transform and opacity instead of layout properties
Preload fonts
mediumPreload custom fonts to prevent font-swap layout shifts
Use font-display: optional
lowConsider using optional font-display to prevent flash of unstyled text
INP
0/6Optimize event handlers
highKeep click, input, and key handlers under 50ms
Break up long tasks
highUse setTimeout or requestIdleCallback to yield to the main thread
Reduce JavaScript execution time
highRemove unused JavaScript and split code bundles
Use web workers
mediumMove expensive computations off the main thread
Optimize third-party scripts
mediumLoad analytics and marketing scripts asynchronously or on interaction
Debounce input handlers
mediumDon't process every keystroke - use debouncing for search inputs
Frequently Asked Questions
What are passing Core Web Vitals scores?+
LCP should be under 2.5 seconds, CLS under 0.1, and INP under 200ms. These thresholds apply to the 75th percentile of page loads.
How do I check my Core Web Vitals?+
Use Google PageSpeed Insights, Chrome DevTools, or our free speed test tool. For real user data, check Google Search Console's Core Web Vitals report.
Which Core Web Vital is most important?+
All three matter for Google's page experience ranking signal. However, LCP often has the most immediate impact on user experience and is typically the easiest to improve.
Test Your Progress
Run a speed test to see how your optimizations have improved your Core Web Vitals.