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.
1.47 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.30 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
1 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.001
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
2.85 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.
2.30 s
Page Load Progression
FPage Weight BudgetAction16.0 MB transferred, 115 requestsFIX
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.
Source: web.dev
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
DPage Weight InventoryAction115 resources · 16.0 MB · 224 KB savings availableFIX
~223.9 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 115 resources | 16.0 MiB | ||||||
CImage OptimizationAction44 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
BJS Execution Cost674ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 213ms | 4ms | 0ms | 3rd |
| https://www.etsi.org/ | 188ms | 8ms | 3ms | 3rd |
| https://www.etsi.org/wp-content/plugins/webtoffee-cookie-consent/lite/frontend/js/script.min.js?ver=3.5.1 | 107ms | 21ms | 1ms | 3rd |
| https://www.etsi.org/wp-includes/js/jquery/jquery.min.js?ver=3.7.1 | 98ms | 54ms | 2ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-L34WJL1P2Z&cx=c>m=4e64m0h2 | 67ms | 55ms | 11ms | 3rd |
CJS BundlesAction31 scripts, 224 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-L34WJL1P2Z&cx=c>m=4e64m0h2 | 176 KB | 70 KB (40%) | ✓ | 3rd |
| https://www.juicer.io/embed_juicer20.js | 83 KB | 64 KB (78%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-NM67VXCX | 123 KB | 62 KB (51%) | ✓ | 3rd |
| https://www.etsi.org/wp-content/themes/etsi/js/swiper-bundle.min.js?ver=1.0 | 43 KB | 27 KB (64%) | ✓ | 3rd |
| https://www.etsi.org/wp-content/themes/etsi/js/etsi-builder-tabs-ajax.js?ver=1775031524 | 1 KB | — | ✓ | 3rd |
| https://www.etsi.org/wp-content/plugins/sfwd-lms/themes/ld30/assets/js/learndash.js?ver=5.0.4 | 13 KB | — | ✗ | 3rd |
| https://www.etsi.org/wp-content/plugins/uncanny-learndash-toolkit/src/assets/frontend/dist/bundle.min.js?ver=3.8.0.2 | 8 KB | — | ✓ | 3rd |
| https://www.etsi.org/wp-content/plugins/sfwd-lms/includes/course-grid/templates/skins/grid/script.js?ver=5.0.4 | 1 KB | — | ✓ | 3rd |
| https://www.etsi.org/wp-content/plugins/sfwd-lms/includes/course-grid/assets/js/script.js?ver=5.0.4 | 3 KB | — | ✓ | 3rd |
| https://www.etsi.org/wp-content/plugins/learndash-certificate-verify-and-share/assets/js/frontend.js?ver=1.6.28 | 3 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
A+Text CompressionAll text resources are compressedPASS
A+Font Loading6 fonts (158 KB)PASS
Web fonts
6
158 KB total
Render-blocking
0
of 6
Dominant font-display
swap
Most common across fonts
Font loading timeline
- 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 ~2 KB and ~4 ms
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
AHTTP Cachingmax-age=3600 (1 hour)PASS
max-age=3600
| Directive | Value | Meaning |
|---|---|---|
| max-age | 3600 | Cache for 1 hour |
Network Waterfall115 requests over 3839msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 213ms | 0 KB | — | £2/mo | Costly |
www.etsi.org www.etsi.org | Other | 188ms | 32 KB | — | £2/mo | Optional |
www.etsi.org www.etsi.org | Other | 107ms | 13 KB | — | £1/mo | Optional |
www.etsi.org www.etsi.org | Other | 98ms | 31 KB | — | £1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 67ms | 176 KB | 40% | £1/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 213ms and costs ~£2/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
Unattributable takes 213ms 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