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Performance Analysis

Speed wins.

Page speed directly impacts user experience and search rankings. According to Google, 53% of mobile users abandon sites that take longer than 3 seconds to load. Our performance engine measures Core Web Vitals (LCP, INP, CLS), identifies render-blocking resources, and checks image optimisation. Having audited thousands of pages, we found that most sites can cut load times by 40% with a handful of targeted fixes.

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53%

of mobile users abandon sites that take over 3 seconds to load

7%

decrease in conversions for every 1-second delay

2x

more pages viewed on sites loading under 2 seconds

What is performance analysis? A web performance audit measures how quickly a website loads and responds to user interaction, analysing Core Web Vitals (LCP, INP, CLS), resource sizes, server response times, caching, and render-blocking resources to identify bottlenecks.

What We Check

Comprehensive feature breakdown

Core Web Vitals

  • Largest Contentful Paint (LCP) analysis
  • Cumulative Layout Shift (CLS) measurement
  • Interaction to Next Paint (INP) assessment
  • First Contentful Paint (FCP) tracking
  • Time to First Byte (TTFB) evaluation
  • Total Blocking Time (TBT) measurement

Resource Optimisation

  • Image format and compression analysis
  • JavaScript bundle size review
  • CSS optimisation opportunities
  • Font loading strategy assessment
  • Third-party script impact analysis
  • Unused code detection

Caching & Delivery

  • Browser caching header validation
  • CDN configuration checks
  • Compression (gzip/brotli) verification
  • Resource hint usage (preload, prefetch)
  • HTTP/2 and HTTP/3 support
  • Server response time analysis

Methodology

How we audit

1

Page Load Simulation

We simulate page loads in controlled environments to measure real loading performance.

2

Resource Waterfall Analysis

Every resource request is mapped to identify bottlenecks, blocking resources, and inefficient loading.

3

Core Web Vitals Measurement

LCP, CLS, and INP are measured and compared against Google's thresholds for good user experience.

4

Impact-Ranked Recommendations

Findings are ranked by potential performance gain, so you get the biggest speed improvements first.

Common Findings

Issues we commonly detect

Unoptimised images

critical

Oversized images are the number one cause of slow page loads, often adding megabytes of unnecessary data.

Render-blocking JavaScript

serious

Scripts that block rendering delay the first paint, making pages feel sluggish to users.

No browser caching

serious

Without caching headers, returning visitors must re-download every resource on every visit.

Excessive third-party scripts

moderate

Analytics, ads, and widgets from external domains add significant latency and unpredictability.

Layout shift from late-loading content

moderate

Elements that shift after initial render create a jarring experience and hurt CLS scores.

No text compression

minor

Serving uncompressed HTML, CSS, and JS wastes bandwidth and slows page delivery.

Key Takeaways

  • Measures Core Web Vitals (LCP, INP, CLS) alongside server response time and resource optimisation.
  • Every second of load time costs roughly 7% in conversions.
  • Performance is a direct Google ranking factor via Core Web Vitals.

Why performance matters for your business

Every second of load time costs conversions. Faster sites rank higher, convert better, and keep users engaged.

FAQ

Frequently asked questions

What are Core Web Vitals?

Core Web Vitals are three metrics Google uses to measure user experience: Largest Contentful Paint (LCP) measures loading speed, Interaction to Next Paint (INP) measures responsiveness, and Cumulative Layout Shift (CLS) measures visual stability. All three are ranking factors.

What is a good page load time?

Google recommends LCP under 2.5 seconds, INP under 200 milliseconds, and CLS under 0.1. For overall page load, aim for under 3 seconds on mobile. Kritano measures all of these and flags pages that miss the targets.

How does performance affect SEO?

Page speed is a direct Google ranking factor. Core Web Vitals are part of the Page Experience signals. Slow pages also have higher bounce rates and lower engagement, which indirectly hurt rankings through user behaviour signals.

Complete Coverage

Explore other audit dimensions

SEO Auditing

Get found. Get traffic.

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Accessibility (WCAG 2.2)

Inclusive by design.

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Security Scanning

Protect your visitors.

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Find out what's slowing you down

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