Google PageSpeed Insights API v5 · Core Web Vitals
Free Website PageSpeed Test. Core Web Vitals & Performance Audit.
Test any website's mobile and desktop performance powered directly by the official Google PageSpeed API. Analyze real-user metrics, LCP, INP, CLS, and high-impact technical speed fixes.
Analyzing Website Performance
Connecting to Google PageSpeed Insights API v5...
Simulating mobile device loading and calculating Core Web Vitals. This typically takes 8-15 seconds.
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Performance Score
Loading performance verdict...
90-100: Good / Fast
50-89: Needs Improvement
0-49: Poor / Slow
Automated estimate only. Not proof of authorship, not a guarantee of rankings or compliance, and not professional advice. Review before use. See Terms.
Google Core Web Vitals (Lab Telemetry)
Core Performance Metrics
LCP
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Largest Contentful Paint
Time taken to render the primary visual element on the screen.
Target: ≤ 2.5s
TBT
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Total Blocking Time
Total time the main thread was blocked from responding to input.
Target: ≤ 200ms
CLS
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Cumulative Layout Shift
Visual stability score measuring unexpected element jumps.
Target: ≤ 0.10
FCP
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First Contentful Paint
Initial moment any text or image is painted in the browser.
Target: ≤ 1.8s
SI
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Speed Index
How rapidly the visual contents of a page become visible.
Target: ≤ 3.4s
TTFB
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Time to First Byte
Backend server response latency and network delivery time.
Target: ≤ 0.8s
Technical Performance Engineering
Turn Web Speed Into Conversion Advantage.
Every 1-second improvement in page speed directly lifts conversions by up to 20% on mobile and protects your Google search positions. Want our engineering team to audit your frontend codebase and server stack?
Why Core Web Vitals Matter
Google uses Core Web Vitals as official ranking signals. Slow pages lose organic rankings, experience higher ad bounce rates, and bleed conversion margins.
Mobile-First Lighthouse v5
Simulates real-world mobile 4G network throttling and mid-tier CPU execution so you see what actual users experience, not just idealized lab conditions.
Zero API Key Needed
Audits are executed directly against Growingo's dedicated Google Cloud API infrastructure with transient caching for instant retests.