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.
752 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.60 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
0 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.021
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
902 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.
1.61 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
DPage Weight InventoryAction74 resources · 1.6 MB · 248 KB savings availableFIX
~247.8 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 74 resources | 1.6 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CPage Weight BudgetAction1.6 MB transferred, 74 requestsREVIEW
Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.
CSS bundle is large — purge unused styles (PurgeCSS, Tailwind JIT) to reduce CSS payload.
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
CImage OptimizationAction12 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
CJS BundlesAction27 scripts, 248 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://european-union.europa.eu/sites/default/files/js/js_JP6x4lPIakp0N_pEt4lfZguYmvs1ixMQFHYBOHl9z9E.js?scope=footer&delta=3&language=en&theme=ewcms_theme&include=eJxVy9EOgjAMheEXQnmkpoyTOdOtpO1A3l5BjfGu5_tTbKk61S5RpLTcWUacdHcSPiCDGrJG4SjahneNGypGJPJuK_Z_PW9uLHuU5IPiE5LWRRtakJTJ2HZC_1U8AvZ6Il_zoRumUBUfZ-sLy_W7L17ZQpRn2BOXg0xX | 74 KB | 66 KB (90%) | ✓ | 3rd |
| https://european-union.europa.eu/sites/default/files/js/js_JP6x4lPIakp0N_pEt4lfZguYmvs1ixMQFHYBOHl9z9E.js?scope=footer&delta=3&language=en&theme=ewcms_theme&include=eJyVjdEOgzAIRX_IrZ9EsBIloWAo1bmvnzNdlj3uDc49F2jPpcJizk_TQIFC2hLm4I0gHFkGupTSJFhY54aSOsK8sF6aVsFg079kUAM5__RSLFQoUYbafKPjl14zKsoRnOtg1INsZTUljfPS6OgHUPum9AjyswR1m990pzHMpKbJ24py_-y3WtBDDCfyF6mcboQ | 74 KB | 60 KB (82%) | ✓ | 3rd |
| https://webtools.europa.eu/js/webtools.etrans.js?t=cdb5c65d | 115 KB | 35 KB (31%) | ✓ | 3rd |
| https://webtools.europa.eu/load.js | 0 KB | 22 KB (55%) | ✓ | 3rd |
| https://webtools.europa.eu/load.js | 42 KB | 22 KB (55%) | ✓ | 3rd |
| https://european-union.europa.eu/core/assets/vendor/jquery/jquery.min.js?v=4.0.0-rc.1 | 0 KB | 21 KB (77%) | ✓ | 3rd |
| https://european-union.europa.eu/core/assets/vendor/jquery/jquery.min.js?v=4.0.0-rc.1 | 27 KB | 21 KB (77%) | ✓ | 3rd |
| https://european-union.europa.eu/themes/contrib/oe_theme/dist/duet/duet/duet.esm.js | 0 KB | — | ✓ | 3rd |
| https://ec.europa.eu/wel/surveys/wr_survey03/js/main.js?986866 | 7 KB | — | ✓ | 3rd |
| https://european-union.europa.eu/sites/default/files/js/js_vveTWHZoEhX4bTWIlnayw7kuUGewgAxDHPAy-uze0_c.js?scope=footer&delta=1&language=en&theme=ewcms_theme&include=eJxVy9EOgjAMheEXQnmkpoyTOdOtpO1A3l5BjfGu5_tTbKk61S5RpLTcWUacdHcSPiCDGrJG4SjahneNGypGJPJuK_Z_PW9uLHuU5IPiE5LWRRtakJTJ2HZC_1U8AvZ6Il_zoRumUBUfZ-sLy_W7L17ZQpRn2BOXg0xX | 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
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
A+Text CompressionAll text resources are compressedPASS
A+JS Execution Cost287ms total JS executionPASS
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://webtools.europa.eu/load.js | 117ms | 60ms | 7ms | 3rd |
| Unattributable | 90ms | 2ms | 0ms | 3rd |
| https://european-union.europa.eu/index_en | 80ms | 2ms | 0ms | 3rd |
A+Font LoadingNo web fonts (system fonts)PASS
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall74 requests over 1153msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
webtools.europa.eu webtools.europa.eu | Other | 117ms | 0 KB | 55% | €1/mo | Optional |
Unattributable Unattributable | Other | 90ms | 0 KB | — | €1/mo | Optional |
european-union.europa.eu european-union.europa.eu | Other | 80ms | 18 KB | — | €1/mo | Optional |
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
55% of webtools.europa.eu'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