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.
5.49 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
6.05 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
1.69 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.004
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
6.42 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.
16.01 s
Page Load Progression
FPage Weight BudgetAction3.6 MB transferred, 120 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
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.
Source: web.dev
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction7782ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 1239ms | 1027ms | 128ms | 3rd |
| https://www.bsigroup.com/build/assets/swiper-bundle-r8-hi7mH.js | 1162ms | 395ms | 1ms | 3rd |
| https://edge.eu1.fullstory.com/s/fs.js | 1116ms | 938ms | 40ms | 3rd |
| Unattributable | 1084ms | 21ms | 0ms | 3rd |
| https://www.bsigroup.com/ | 1073ms | 121ms | 35ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WX52CM | 751ms | 642ms | 94ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202510.2.0/otBannerSdk.js | 519ms | 338ms | 101ms | 3rd |
| https://cdn.optimizely.com/js/24631140947.js | 406ms | 328ms | 44ms | 3rd |
| https://www.dwin1.com/25134.js | 102ms | 77ms | 22ms | 3rd |
| https://static.ads-twitter.com/uwt.js | 89ms | 82ms | 6ms | 3rd |
Showing top 10 of 14 scripts
FJS BundlesAction53 scripts, 954 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 0 KB | 177 KB (49%) | ✓ | 3rd |
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 0 KB | 177 KB (49%) | ✓ | 3rd |
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 362 KB | 177 KB (49%) | ✓ | 3rd |
| https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js | 362 KB | 177 KB (49%) | ✓ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202510.2.0/otBannerSdk.js | 124 KB | 65 KB (52%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WX52CM | 187 KB | 60 KB (32%) | ✓ | 3rd |
| https://cdn.optimizely.com/js/24631140947.js | 99 KB | 49 KB (49%) | ✓ | 3rd |
| https://edge.eu1.fullstory.com/s/fs.js | 80 KB | 27 KB (34%) | ✓ | 3rd |
| https://www.bsigroup.com/build/assets/swiper-bundle-r8-hi7mH.js | 44 KB | 24 KB (56%) | ✓ | 3rd |
| https://www.bsigroup.com/ui/js/libs/jquery-3.5.1.min.js | 31 KB | 23 KB (75%) | ✓ | 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 InventoryAction120 resources · 3.6 MB · 954 KB savings availableFIX
~954.1 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 120 resources | 3.6 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization28 images, 0 KB saveableREVIEW
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+Font Loading4 fonts (119 KB)PASS
Web fonts
4
119 KB total
Render-blocking
0
of 4
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 Hints4 hints, 0 missing preconnectsPASS
Current Resource Hints
4 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall120 requests over 6217msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.gstatic.com www.gstatic.com | Other | 1239ms | 0 KB | 49% | £21/mo | Costly |
www.bsigroup.com www.bsigroup.com | Other | 1162ms | 44 KB | 56% | £20/mo | Costly |
edge.eu1.fullstory.com edge.eu1.fullstory.com | Other | 1116ms | 80 KB | 34% | £19/mo | Costly |
Unattributable Unattributable | Other | 1084ms | 0 KB | — | £19/mo | Costly |
www.bsigroup.com www.bsigroup.com | Other | 1073ms | 40 KB | — | £19/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 751ms | 187 KB | 32% | £13/mo | Costly |
OneTrust cdn.cookielaw.org | Consent | 519ms | 124 KB | 52% | £9/mo | Essential |
Optimizely cdn.optimizely.com | A/B Testing | 406ms | 99 KB | 49% | £7/mo | Costly |
www.dwin1.com www.dwin1.com | Other | 102ms | 16 KB | — | £2/mo | Optional |
Twitter/X Pixel static.ads-twitter.com | Advertising | 89ms | 13 KB | — | £2/mo | Optional |
OneTrust cdn.cookielaw.org | Consent | 75ms | 5 KB | — | £1/mo | Essential |
www.bsigroup.com www.bsigroup.com | Other | 59ms | 31 KB | 75% | £1/mo | Optional |
edge.eu1.fullstory.com edge.eu1.fullstory.com | Other | 58ms | 14 KB | — | £1/mo | Optional |
OneTrust cdn.cookielaw.org | Consent | 50ms | 10 KB | — | £1/mo | Essential |
These scripts may cost more than they're worth
- www.gstatic.com adds 1239ms and costs ~£21/month
- www.bsigroup.com adds 1162ms and costs ~£20/month
- edge.eu1.fullstory.com adds 1116ms and costs ~£19/month
- Unattributable adds 1084ms and costs ~£19/month
- www.bsigroup.com adds 1073ms and costs ~£19/month
- Google Tag Manager adds 751ms and costs ~£13/month
- Optimizely adds 406ms and costs ~£7/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.gstatic.com takes 1239ms 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.bsigroup.com takes 1162ms 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
56% of www.bsigroup.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
edge.eu1.fullstory.com takes 1116ms 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 1084ms 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.bsigroup.com takes 1073ms 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
Google Tag Manager takes 751ms 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
52% of OneTrust'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
Optimizely takes 406ms 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
75% of www.bsigroup.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