Performance
· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
813 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.94 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
92 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.288
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
948 ms
Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.
2.85 s
Page Load Progression
375 ms
750 ms
1.1 s 1.5 s 1.9 s 2.2 s 2.6 s 3.0 sDPage Weight BudgetAction2.3 MB transferred, 75 requestsFIX
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.
Source: web.dev
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS BundlesAction14 scripts, 674 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.iihs.org/Frontend/build/home_2ca77d33fe1636899f91.js | 252 KB | 175 KB (69%) | ✓ | 3rd |
| https://www.iihs.org/Frontend/build/allnav_2a69d9e45434821d7ee1.js | 174 KB | 119 KB (69%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-NFDVV9L | 148 KB | 107 KB (72%) | ✓ | 3rd |
| https://www.iihs.org/5qrd/?id=G-ELVP0YFQNX&cx=c>m=4e64k1 | 183 KB | 74 KB (40%) | ✓ | 3rd |
| https://www.iihs.org/5qrd/ | 153 KB | 66 KB (43%) | ✓ | 3rd |
| https://www.iihs.org/5qrd/?id=AW-489333236&cx=c>m=4e64k1 | 144 KB | 56 KB (39%) | ✓ | 3rd |
| https://www.iihs.org/5qrd/?id=AW-11110660618&cx=c>m=4e64k1 | 150 KB | 55 KB (37%) | ✓ | 3rd |
| https://cdn-cookieyes.com/client_data/04b714e0391022df89db315d/banner.js | 38 KB | 22 KB (57%) | ✓ | 3rd |
| https://static.cloudflareinsights.com/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da1771523124516 | 11 KB | — | ✓ | 3rd |
| https://kit.fontawesome.com/2f7b88d0db.js | 6 KB | — | ✓ | 3rd |
Consider code splitting or tree shaking to reduce unused code.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
Consider code splitting or tree shaking to reduce unused code.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
Consider code splitting or tree shaking to reduce unused code.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
Consider code splitting or tree shaking to reduce unused code.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
Consider code splitting or tree shaking to reduce unused code.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
FPage Weight InventoryAction75 resources · 2.3 MB · 674 KB savings availableFIX
~674.2 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 75 resources | 2.3 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction29 images, 0 KB saveableREVIEW
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
BJS Execution Cost950ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.iihs.org/ | 231ms | 3ms | 1ms | 3rd |
| https://cdn-cookieyes.com/client_data/04b714e0391022df89db315d/banner.js | 205ms | 163ms | 5ms | 3rd |
| Unattributable | 114ms | 8ms | 0ms | 3rd |
| https://www.iihs.org/Frontend/build/allnav_2a69d9e45434821d7ee1.js | 103ms | 69ms | 22ms | 3rd |
| https://www.iihs.org/Frontend/build/home_2ca77d33fe1636899f91.js | 88ms | 62ms | 22ms | 3rd |
| https://www.iihs.org/5qrd/ | 80ms | 62ms | 17ms | 3rd |
| https://www.iihs.org/5qrd/?id=G-ELVP0YFQNX&cx=c>m=4e64k1 | 73ms | 53ms | 19ms | 3rd |
| https://www.iihs.org/5qrd/?id=AW-11110660618&cx=c>m=4e64k1 | 57ms | 41ms | 16ms | 3rd |
A+Text CompressionAll text resources are compressedPASS
A+Font Loading2 fonts (31 KB)PASS
Web fonts
2
31 KB total
Render-blocking
0
of 2
Dominant font-display
swap
Most common across fonts
Font loading timeline
Optimization checklist
- Preload critical fonts (priority=high)
- Use woff2 format for all fonts
- Set font-display to swap, optional, or fallback
- Subset large fonts (≤100 KB each)
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall75 requests over 1477msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.iihs.org www.iihs.org | Other | 231ms | 10 KB | — | €4/mo | Costly |
cdn-cookieyes.com cdn-cookieyes.com | Other | 205ms | 38 KB | 57% | €3/mo | Costly |
Unattributable Unattributable | Other | 114ms | 0 KB | — | €2/mo | Optional |
www.iihs.org www.iihs.org | Other | 103ms | 174 KB | 69% | €2/mo | Optional |
www.iihs.org www.iihs.org | Other | 88ms | 252 KB | 69% | €1/mo | Optional |
www.iihs.org www.iihs.org | Other | 80ms | 153 KB | 43% | €1/mo | Optional |
www.iihs.org www.iihs.org | Other | 73ms | 183 KB | 40% | €1/mo | Optional |
www.iihs.org www.iihs.org | Other | 57ms | 150 KB | 37% | €1/mo | Optional |
These scripts may cost more than they're worth
- www.iihs.org adds 231ms and costs ~€4/month
- cdn-cookieyes.com adds 205ms and costs ~€3/month
100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
When third-party JS execution time exceeds your own, performance gains from frontend work are capped by code you don't own.
Learn more ▾ ▴
Every millisecond of third-party JS competes with your own for main-thread time. If their share is bigger than yours, optimization on your code base barely moves the needle. Audit, defer, or remove third-parties before further frontend optimization. Use Lighthouse's third-party audit to identify the worst offenders.
Source: web.dev
www.iihs.org takes 231ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
cdn-cookieyes.com takes 205ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
57% of cdn-cookieyes.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
69% of www.iihs.org's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
69% of www.iihs.org's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev