Google PageSpeed Insights API v5 · Core Web Vitals

Free Website PageSpeed Test. Core Web Vitals & Performance Audit.

Q: Does Google PageSpeed score directly affect SEO rankings and Google Ads CPC?

Yes. Core Web Vitals (LCP, INP, CLS) are confirmed Google Search ranking signals, and Landing Page Experience directly governs Google Ads Quality Score and cost-per-click (CPC).

Q: What is the fastest way to fix Largest Contentful Paint (LCP) over 2.5 seconds?

Three steps fix 90% of LCP failures: (1) use loading=eager and fetchpriority=high on your hero image, (2) convert large PNG/JPEG banners to AVIF or WebP under 60KB, and (3) inline critical above-the-fold CSS.

Q: How do I fix Cumulative Layout Shift (CLS) on mobile pages?

Add explicit width and height attributes to all img, video, and iframe tags, use 100dvh instead of 100vh for mobile hero containers, and pair web fonts with metric-matched native system fallbacks.

Q: How does Growingo engineer sub-second websites for hospital and B2B chains?

In Stage 03 Growth Execution, Growingo replaces bloated third-party page builders with zero-render-blocking CSS tokens, AVIF hero preloads, and edge HTML caching, lifting mobile PageSpeed scores into the 95-100 green zone.

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.

1. Enter Website URL to Test Google PSI v5 Live

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.

https://example.com MOBILE

-- / 100

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 --

Largest Contentful Paint

Time taken to render the primary visual element on the screen.

Target: ≤ 2.5s

TBT --

Total Blocking Time

Total time the main thread was blocked from responding to input.

Target: ≤ 200ms

CLS --

Cumulative Layout Shift

Visual stability score measuring unexpected element jumps.

Target: ≤ 0.10

FCP --

First Contentful Paint

Initial moment any text or image is painted in the browser.

Target: ≤ 1.8s

SI --

Speed Index

How rapidly the visual contents of a page become visible.

Target: ≤ 3.4s

TTFB --

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 your engineering team to audit your frontend codebase and server stack?

Schedule Architecture Audit →

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.

GOOGLE CORE WEB VITALS & CONVERSION ENGINEERING // GROWINGO SPEED OS

How Mobile PageSpeed & Core Web Vitals Dictate Your ROAS

Every extra second of mobile load time kills up to 20% of paid ad conversions. Diagnose your LCP, TBT, CLS, and TTFB bottlenecks using real Google Lighthouse v5 telemetry.

          ⚡ Direct Answer: What Is a Good Google PageSpeed & Core Web Vitals Score?
        

To pass Google's Core Web Vitals test and hit a 90+ PageSpeed test score on mobile and desktop, your website must meet four strict thresholds at the 75th percentile of real loads: Largest Contentful Paint (LCP) ≤ 2.5 seconds, Total Blocking Time (TBT) / Interaction to Next Paint (INP) ≤ 200ms, Cumulative Layout Shift (CLS) ≤ 0.10, and Time to First Byte (TTFB) ≤ 0.8 seconds.

01 // COMMERCIAL LATENCY ECONOMICS

Why a 4-Second Mobile Load Time Destroys Paid Media Efficiency

Over 84% of healthcare and high-intent consumer search traffic in India and global markets arrives on mobile 4G and 5G devices. You pay Google Ads or Meta for every single click. When a patient taps your cataract, IVF, or orthopedic surgery ad and stares at a blank white screen for 4.2 seconds because of unoptimized hero images and render-blocking JavaScript, 38% bounce before the page even paints. You still pay for that click. Your Cost Per Qualified Lead (CPQL) doubles. Worse, Google Ads penalizes your Landing Page Experience Quality Score.

METRIC 01 // LCP ≤ 2.5s

Largest Contentful Paint (LCP)

Measures how fast your hero headline or banner image renders. Fix slow LCP by serving responsive AVIF or WebP images, adding fetchpriority="high" and loading="eager" to the hero asset, and inlining critical CSS tokens.

METRIC 02 // TBT & INP ≤ 200ms

Main-Thread Responsiveness

When third-party tracking pixels, chat widgets, and heavy React bundles lock up the browser main thread, taps on your appointment button freeze. Defer non-critical scripts. Keep main-thread blocking under 200 milliseconds.

METRIC 03 // CLS ≤ 0.10

Cumulative Layout Shift (CLS)

Nothing erodes trust faster than a page jumping mid-tap because an image or web font loaded late without reserved dimensions. Always declare explicit width and height attributes and metric-matched system font fallbacks.

METRIC 04 // TTFB ≤ 800ms

Time to First Byte (TTFB)

Bloated WordPress plugins running 140 unindexed SQL queries per request push server TTFB past 2.4 seconds before a single byte reaches the browser. Edge HTML caching and deterministic routing cut TTFB under 50ms.

02 // GOOGLE LIGHTHOUSE V5 BENCHMARK REFERENCE

Official Google Core Web Vitals Thresholds & Engineering Fixes

Use this engineering reference table alongside your live website speed test report above to prioritize frontend and server optimizations:

Core Metric	Good (Green)	Needs Work	Poor (Red)	Highest-Impact Engineering Fix
LCP (Largest Contentful Paint)	≤ 2.5 sec	2.5s – 4.0s	> 4.0 sec	Preload hero AVIF image with `fetchpriority="high"`; inline critical CSS
TBT / INP (Blocking / Interaction)	≤ 200 ms	200ms – 500ms	> 500 ms	Defer third-party GTM/analytics scripts; eliminate unused JS bundles
CLS (Cumulative Layout Shift)	≤ 0.10	0.10 – 0.25	> 0.25	Set explicit `width`/`height` on all `<img>` & `<svg>` elements; use `font-display: swap`
FCP (First Contentful Paint)	≤ 1.8 sec	1.8s – 3.0s	> 3.0 sec	Remove render-blocking external stylesheets; enable Brotli/Gzip compression
TTFB (Time to First Byte)	≤ 0.8 sec	0.8s – 1.8s	> 1.8 sec	Deploy server-side full-page HTML caching and CDN edge delivery

03 // FREQUENTLY ASKED QUESTIONS

Technical Questions on Website Speed Tests, Mobile LCP & Core Web Vitals

Why is my Mobile PageSpeed score so much lower than my Desktop score?

Google Lighthouse simulates mobile tests using a throttled 4G connection (1.6 Mbps download, 150ms RTT latency) and a 4x CPU slowdown to reflect mid-tier smartphones. Uncompressed images and heavy JavaScript bundles that load fast on fiber Wi-Fi and a desktop processor stall out on mobile hardware.

Does Google PageSpeed score directly affect SEO rankings and Google Ads CPC?

Yes, it does. Core Web Vitals (LCP, INP, CLS) are confirmed Google Search ranking signals, and Landing Page Experience is one of the three core components of Google Ads Quality Score. Faster landing pages earn higher Quality Scores, lower your cost-per-click (CPC), and convert more visitors into booked consultations. Pair your speed test with our Free Google SEO Audit and Free AEO Benchmark.

What's the fastest way to fix Largest Contentful Paint (LCP) over 2.5 seconds?

Three steps fix 90% of LCP failures: (1) don't lazy-load your above-the-fold hero image (use loading="eager" and fetchpriority="high"), (2) convert large PNG/JPEG banners to next-gen AVIF or WebP under 60KB, and (3) inline critical above-the-fold CSS so the browser doesn't wait on external stylesheets.

How do I fix Cumulative Layout Shift (CLS) on mobile pages?

Add explicit width and height attributes to every <img>, <video>, and <iframe> tag. Use 100dvh instead of 100vh for mobile hero containers so address bar resizing doesn't jump the layout, and pair web fonts with metric-matched native system fallbacks.

How does this PageSpeed test compare my site against 3 category leaders?

When you enter your website URL, our engine detects your industry vertical (such as Eye Care, IVF, Multi-Specialty Hospitals, SaaS, or E-Commerce) and surfaces up to 3 category leader domains right below the console so you can benchmark their mobile and desktop speed side-by-side in one click.

How does Growingo engineer sub-second websites for hospital and B2B chains?

In Stage 03 (Growth Execution), we replace bloated third-party page builders with zero-render-blocking CSS tokens, AVIF hero preloads, and edge HTML caching. That lifts mobile PageSpeed scores into the 95-100 green zone and cuts patient acquisition costs across Google Ads and Meta.

STAGE 01 // TECHNICAL ARCHITECTURE & CONVERSION AUDIT

Losing Paid Ad Clicks to Slow Mobile Load Times?

Book a 45-minute diagnosis session. We'll audit your Core Web Vitals, Google Ads Quality Score leakage, and D-1 revenue attribution pipeline.

Book 45-Minute Growth Diagnosis →