Web Vitals

WebStadia tracks Core Web Vitals for your deployed sites, giving you real-user performance data directly in the dashboard.

Tracked Metrics

Metric	Full Name	What It Measures	Good	Needs Improvement	Poor
LCP	Largest Contentful Paint	Loading speed	≤ 2.5s	≤ 4.0s	> 4.0s
FCP	First Contentful Paint	Time to first render	≤ 1.8s	≤ 3.0s	> 3.0s
CLS	Cumulative Layout Shift	Visual stability	≤ 0.1	≤ 0.25	> 0.25
INP	Interaction to Next Paint	Responsiveness	≤ 200ms	≤ 500ms	> 500ms
TTFB	Time to First Byte	Server response time	≤ 800ms	≤ 1800ms	> 1800ms

Reading Your Scores

Web Vitals are shown on your website's analytics page under the Web Vitals section. Each metric displays:

• P75 value — the 75th percentile score from real users
• Rating badge — color-coded as green (good), yellow (needs improvement), or red (poor)
• Trend chart — daily P75 values over the last 30 days

tip

The P75 (75th percentile) means 75% of your users experience this score or better. Google uses P75 for its Core Web Vitals assessment.

Improving Your Scores

LCP (Loading Speed)

• Optimize and compress images
• Use WebStadia's CDN for assets
• Minimize render-blocking JavaScript and CSS
• Preload critical resources

FCP (First Render)

• Reduce server response time
• Remove render-blocking resources
• Minimize CSS file size
• Use font-display: swap for web fonts

CLS (Layout Stability)

• Set explicit width/height on images and videos
• Avoid inserting content above existing content
• Use CSS aspect-ratio for media elements
• Avoid dynamically injected ads or banners

INP (Responsiveness)

• Break up long JavaScript tasks
• Minimize main thread work
• Use requestAnimationFrame for visual updates
• Defer non-critical JavaScript

TTFB (Server Response)

• WebStadia's CDN automatically optimizes this
• Use static generation where possible
• Minimize server-side redirects

Data Retention

Web Vitals data is retained for 30 days of daily aggregates. Historical data beyond 30 days is automatically cleaned up.