Optimize Large Images and Formats

How to optimize en.saif.sjtu.edu.cn

Generic SiteScore: 56/100Analyzed June 2026Re-analyze this site

Optimize Large Images and Formats

High Impact+25 points estimated

Why It Matters

Images are causing 25.6 second LCP delay and consuming 8MB of unnecessary bandwidth.

How to Fix

Convert all slider images to WebP/AVIF format for 60-70% size reduction. Resize images to match display dimensions (417x199px for mobile sliders instead of 2560x1219px). Add explicit width and height attributes to prevent layout shifts. Implement responsive images using srcset for different screen sizes.

0Needs Improvement

What This Score Means

A score of 56 falls in the "Needs Improvement" range (50-89). While it is better than poor (0-49), you should aim for 90+ to provide an optimal user experience and maximize SEO benefits.

This site is slower than approximately 35% of similar sites. The main issues affecting performance are image optimization, JavaScript execution time, and layout stability.

Addressing these issues could improve your conversion rate by 15-20% and boost your search engine rankings.

Core Web Vitals Analysis

LCP

Largest Contentful Paint

42.7s
Poor

Good: < 2.5s

Measures how long it takes for the main content to appear on screen

INP

Interaction to Next Paint

16ms
Good

Good: < 200ms

Measures how quickly the page responds to user interactions

CLS

Cumulative Layout Shift

0.11
Needs Improvement

Good: < 0.1

Measures visual stability - how much content shifts during page load

AI Performance Analysis

This website has poor performance with a score of 56/100, primarily due to extremely slow loading times - pages take over 42 seconds to fully load and become interactive. The biggest issue is a massive 5.6MB font file from an external CDN that blocks page rendering, combined with large unoptimized images and videos totaling nearly 25MB of data. The site also suffers from significant layout shifts as content loads, creating a jarring user experience. Immediate fixes should focus on optimizing or removing the heavy font file, compressing images to modern formats like WebP, and adding proper dimensions to images to prevent layout shifts.

Other Optimization Recommendations

Fix Critical Render Blocking Resources

High Impact+20 points estimated

Why It Matters:

CSS and font files are delaying first content paint by 3.6 seconds.

How to Fix:

Add preconnect link for cdn.campuswit.com to save 857ms on font loading. Inline critical CSS for above-the-fold content. Defer non-critical CSS like animate.css using media='print' onload technique. Load the 5.3MB HarmonyOS font asynchronously or use font-display: swap.

Eliminate Layout Shifts from Dynamic Content

Medium Impact+8 points estimated

Why It Matters:

Layout shifts score of 0.108 creates poor user experience as content jumps during loading.

How to Fix:

Reserve fixed dimensions for the swiper text-padding container that's causing major shifts. Add CSS min-height to research-wrap section based on content size. Preload swiper slider dimensions before JavaScript initialization to prevent pagination movement.

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