Performance
· 17 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.
4.97 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
8.65 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
217 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.023
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
4.97 s
Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.
8.87 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
DJS Execution CostAction2880ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.skysports.com/BtymJ/5qB/crZo/YF/VA7oft/SJJOGD5YkO/KHAxAQ/WD44X3Z/gVFwPAg?v=48af0335-0b5b-cdb8-999c-2f744f1d0214 | 1140ms | 1068ms | 42ms | 3rd |
| Unattributable | 533ms | 205ms | 0ms | 3rd |
| https://www.skysports.com/ | 517ms | 78ms | 12ms | 3rd |
| https://www.skysports.com/js/modules-es6/ui-sitewide-carousel-19f58aa5e7e485a4692a.js | 371ms | 236ms | 0ms | 3rd |
| https://browser.covatic.io/sdk/v1/sky.js | 163ms | 130ms | 1ms | 3rd |
| https://cdn.privacy-mgmt.com/unified/wrapperMessagingWithoutDetection.js | 157ms | 129ms | 10ms | 3rd |
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction14 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
BJS Bundles20 scripts, 119 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://browser.covatic.io/sdk/v1/sky.js | 79 KB | 49 KB (62%) | ✓ | 3rd |
| https://www.skysports.com/BtymJ/5qB/crZo/YF/VA7oft/SJJOGD5YkO/KHAxAQ/WD44X3Z/gVFwPAg?v=48af0335-0b5b-cdb8-999c-2f744f1d0214 | 149 KB | 30 KB (20%) | ✓ | 3rd |
| https://www.skysports.com/js/modules-es6/live-components-dbdf09661b7430450c77.js | 23 KB | 20 KB (89%) | ✓ | 3rd |
| https://www.skysports.com/js/modules-es6/omniture-91d9d1cba05d0a55199c.js | 20 KB | 20 KB (100%) | ✓ | 3rd |
| https://www.skysports.com/js/modules-es6/ui-sitewide-tiles-rail-35ec8f476bd936861e18.js | 1 KB | — | ✓ | 3rd |
| https://www.skysports.com/js/modules-es6/ui-token-refresh-d7a91688ca8369a4c1c4.js | 1 KB | — | ✓ | 3rd |
| https://uk-script.dotmetrics.net/door.js?id=11726 | 5 KB | — | ✓ | 3rd |
| https://www.skysports.com/js/modules-es6/sdc-site-a11y-skip-links-88990499e3986aafde68.js | 0 KB | — | ✓ | 3rd |
| https://www.skysports.com/js/modules-es6/ui-digrev-footer-389e3800d818652527a1.js | 1 KB | — | ✓ | 3rd |
| https://www.skysports.com/js/modules-es6/ui-digrev-header-a6a7b2a813f54a217527.js | 1 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
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
APage Weight Budget1.0 MB transferred, 58 requestsPASS
Subset fonts to include only used characters, or switch to system font stacks.
Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).
Source: web.dev font loading
A+Text CompressionAll text resources are compressedPASS
A+Font Loading8 fonts (232 KB)PASS
Web fonts
8
232 KB total
Render-blocking
0
of 8
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
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)
Fixing the unchecked items could save ~32 KB and ~64 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource Hints17 hints, 0 missing preconnectsPASS
Current Resource Hints
17 resource hints configured
APage Weight Inventory58 resources · 1.0 MB · 119 KB savings availablePASS
~119.3 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 58 resources | 1.0 MiB | ||||||
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall58 requests over 3411msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.skysports.com www.skysports.com | Other | 1140ms | 149 KB | 20% | £17/mo | Costly |
Unattributable Unattributable | Other | 533ms | 0 KB | — | £8/mo | Costly |
www.skysports.com www.skysports.com | Other | 517ms | 43 KB | — | £8/mo | Costly |
www.skysports.com www.skysports.com | Other | 371ms | 2 KB | — | £5/mo | Costly |
browser.covatic.io browser.covatic.io | Other | 163ms | 79 KB | 62% | £2/mo | Optional |
cdn.privacy-mgmt.com cdn.privacy-mgmt.com | Other | 157ms | 42 KB | — | £2/mo | Optional |
These scripts may cost more than they're worth
- www.skysports.com adds 1140ms and costs ~£17/month
- Unattributable adds 533ms and costs ~£8/month
- www.skysports.com adds 517ms and costs ~£8/month
- www.skysports.com adds 371ms and costs ~£5/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.skysports.com takes 1140ms 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
Unattributable takes 533ms 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
www.skysports.com takes 517ms 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
www.skysports.com takes 371ms 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
62% of browser.covatic.io'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