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.
7.14 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
25.03 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
3.10 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.031
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
8.33 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.
25.36 s
Page Load Progression
FPage Weight BudgetAction4.7 MB transferred, 75 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
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
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
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction7032ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.epo.org/sites/default/files/js/js_DWmB2C2_HK7pUa6KxglI9AZV_9bBb4mfP-jz3-alDek.js?scope=header&delta=0&language=en&theme=epo_org&include=eJyFUtFyhCAM_CHOvPR_mIA5jxoJA7GO_fqitepd7fQlZDfLwiRxjJ8zuCWaNYJnLIVD0Q2zYLulSXi-B-YfmGUIhTaU8b5lE7lknIgWzZje4Ehv7-XGqFTNfU9tUMkWvZfcBomwZ809S1SK7aHaPayiK7AEQ0nsgzhRtuunqcBvalVJ7oAsE-YYYnc8aaegD-tYfH8p_AgtyXd9L9cGaLWvP-CTe8fikG9FZ64XDY3Wi_SB6jEkDhg9wRVpGGcZdSEkUtQCr8T_imZpaUY27G0J1Xl5YIzayhThgjvpwoAdwQs-1ddmP8NTdW0PvOCnOk3WY5axEMMfvEkPUSlTSARH2oQY1Gz6JGlM25jggjN1X30Pa2zWfVVnB-pwoDiCw7qjS8dGR9sAyuUsvgARazZZ | 1531ms | 1093ms | 1ms | 3rd |
| https://matomo.epo.org/js/container_SPKJjzc5.js | 1506ms | 1478ms | 25ms | 3rd |
| https://www.epo.org/react/specialized-app/vendors.js.gz | 1274ms | 980ms | 247ms | 3rd |
| https://www.epo.org/sites/default/files/js/js_wF4_EV7M-WWCDgU0GmiI2uef6tEDE5d6UadAnyLYOEY.js?scope=footer&delta=0&language=en&theme=epo_org&include=eJyFUtFyhCAM_CHOvPR_mIA5jxoJA7GO_fqitepd7fQlZDfLwiRxjJ8zuCWaNYJnLIVD0Q2zYLulSXi-B-YfmGUIhTaU8b5lE7lknIgWzZje4Ehv7-XGqFTNfU9tUMkWvZfcBomwZ809S1SK7aHaPayiK7AEQ0nsgzhRtuunqcBvalVJ7oAsE-YYYnc8aaegD-tYfH8p_AgtyXd9L9cGaLWvP-CTe8fikG9FZ64XDY3Wi_SB6jEkDhg9wRVpGGcZdSEkUtQCr8T_imZpaUY27G0J1Xl5YIzayhThgjvpwoAdwQs-1ddmP8NTdW0PvOCnOk3WY5axEMMfvEkPUSlTSARH2oQY1Gz6JGlM25jggjN1X30Pa2zWfVVnB-pwoDiCw7qjS8dGR9sAyuUsvgARazZZ | 934ms | 159ms | 40ms | 3rd |
| https://www.epo.org/en | 685ms | 41ms | 6ms | 3rd |
| Unattributable | 644ms | 13ms | 0ms | 3rd |
| https://www.epo.org/cdn-cgi/challenge-platform/scripts/jsd/main.js | 229ms | 210ms | 2ms | 3rd |
| https://www.epo.org/sites/default/files/css/css_8iCArI7X4EZ5liCz2qvl4L-_7oACbpCLwH1GBKpzjzA.css?delta=1&language=en&theme=epo_org&include=eJx1U1mS4yAMvRBt_cx9XCyyQ0UgConJpE8_2Ekl2J3-wbwFFUjPjuz3HYhtiHk1jllFqy1_wFnBEa_EztKX6J1OzoQidkUx_oohKtfZes81RM7w2k1L5ayYw9v1KjGrdQLb8hZjDpjVEfsrDHvTyyFkrslS_EaDhecLUsE6e7IiKPCT2l1c1_MbsM2e-Rqxf1KhaLNH-ETOARfbSA3ZOzfdBM79SgJnwpCfJfZzODThAzf4XFM9mB7E4PC2BjjCUeWWNfBtLPHiBl9cqk0IZ2J0pD5GOOFBr7hgxa0fS0Qar3RShjP7aI9wVPGfwhGOalQa77PjQf8bAzKc8EHH29YtboIEv_Am9cRZWCIp1snbott4HiRjchimZYubdtmUCyvLLRaE93bqwbRknsULl1bmPawCHzgjFHum93XycsTJxv6nNKJbDHo5SHrBPiy5i2J6_Jzq5oRrH2FuP4kt4z3521MF9nVKHFrv3xbY5vCZcoEn_nri_7dFnKE | 229ms | 0ms | 0ms | 3rd |
FJS BundlesAction30 scripts, 844 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.epo.org/react/specialized-app/vendors.js.gz | 831 KB | 604 KB (73%) | ✓ | 3rd |
| https://www.epo.org/sites/default/files/js/js_wF4_EV7M-WWCDgU0GmiI2uef6tEDE5d6UadAnyLYOEY.js?scope=footer&delta=0&language=en&theme=epo_org&include=eJyFUtFyhCAM_CHOvPR_mIA5jxoJA7GO_fqitepd7fQlZDfLwiRxjJ8zuCWaNYJnLIVD0Q2zYLulSXi-B-YfmGUIhTaU8b5lE7lknIgWzZje4Ehv7-XGqFTNfU9tUMkWvZfcBomwZ809S1SK7aHaPayiK7AEQ0nsgzhRtuunqcBvalVJ7oAsE-YYYnc8aaegD-tYfH8p_AgtyXd9L9cGaLWvP-CTe8fikG9FZ64XDY3Wi_SB6jEkDhg9wRVpGGcZdSEkUtQCr8T_imZpaUY27G0J1Xl5YIzayhThgjvpwoAdwQs-1ddmP8NTdW0PvOCnOk3WY5axEMMfvEkPUSlTSARH2oQY1Gz6JGlM25jggjN1X30Pa2zWfVVnB-pwoDiCw7qjS8dGR9sAyuUsvgARazZZ | 137 KB | 82 KB (60%) | ✗ | 3rd |
| https://code.jquery.com/ui/1.12.0/jquery-ui.min.js | 66 KB | 59 KB (89%) | ✓ | 3rd |
| https://www.epo.org/sites/default/files/js/js_waQd_nwm3isAsUoGMT25yi69Clwp7asaO7APd0FqZGM.js?scope=footer&delta=4&language=en&theme=epo_org&include=eJyFUtFyhCAM_CHOvPR_mIA5jxoJA7GO_fqitepd7fQlZDfLwiRxjJ8zuCWaNYJnLIVD0Q2zYLulSXi-B-YfmGUIhTaU8b5lE7lknIgWzZje4Ehv7-XGqFTNfU9tUMkWvZfcBomwZ809S1SK7aHaPayiK7AEQ0nsgzhRtuunqcBvalVJ7oAsE-YYYnc8aaegD-tYfH8p_AgtyXd9L9cGaLWvP-CTe8fikG9FZ64XDY3Wi_SB6jEkDhg9wRVpGGcZdSEkUtQCr8T_imZpaUY27G0J1Xl5YIzayhThgjvpwoAdwQs-1ddmP8NTdW0PvOCnOk3WY5axEMMfvEkPUSlTSARH2oQY1Gz6JGlM25jggjN1X30Pa2zWfVVnB-pwoDiCw7qjS8dGR9sAyuUsvgARazZZ | 69 KB | 47 KB (68%) | ✓ | 3rd |
| https://matomo.epo.org/js/container_SPKJjzc5.js | 65 KB | 28 KB (43%) | ✓ | 3rd |
| https://www.epo.org/sites/default/files/js/js_GmMZdD40B-Es63qGlO_zHegVWbUGZggpTHwJ698wV2k.js?scope=footer&delta=11&language=en&theme=epo_org&include=eJyFUtFyhCAM_CHOvPR_mIA5jxoJA7GO_fqitepd7fQlZDfLwiRxjJ8zuCWaNYJnLIVD0Q2zYLulSXi-B-YfmGUIhTaU8b5lE7lknIgWzZje4Ehv7-XGqFTNfU9tUMkWvZfcBomwZ809S1SK7aHaPayiK7AEQ0nsgzhRtuunqcBvalVJ7oAsE-YYYnc8aaegD-tYfH8p_AgtyXd9L9cGaLWvP-CTe8fikG9FZ64XDY3Wi_SB6jEkDhg9wRVpGGcZdSEkUtQCr8T_imZpaUY27G0J1Xl5YIzayhThgjvpwoAdwQs-1ddmP8NTdW0PvOCnOk3WY5axEMMfvEkPUSlTSARH2oQY1Gz6JGlM25jggjN1X30Pa2zWfVVnB-pwoDiCw7qjS8dGR9sAyuUsvgARazZZ | 31 KB | 25 KB (82%) | ✓ | 3rd |
| https://www.epo.org/react/statistics-centre/load-stats-centre.js | 1 KB | — | ✓ | 3rd |
| https://www.epo.org/react/specialized-app/proceduralcomms.js.gz | 6 KB | — | ✓ | 3rd |
| https://www.epo.org/sites/default/files/js/js_KZF_FBqgjawGzyufh3AlYPY8RtnK6--u4G006H7oJLM.js?scope=footer&delta=9&language=en&theme=epo_org&include=eJyFUtFyhCAM_CHOvPR_mIA5jxoJA7GO_fqitepd7fQlZDfLwiRxjJ8zuCWaNYJnLIVD0Q2zYLulSXi-B-YfmGUIhTaU8b5lE7lknIgWzZje4Ehv7-XGqFTNfU9tUMkWvZfcBomwZ809S1SK7aHaPayiK7AEQ0nsgzhRtuunqcBvalVJ7oAsE-YYYnc8aaegD-tYfH8p_AgtyXd9L9cGaLWvP-CTe8fikG9FZ64XDY3Wi_SB6jEkDhg9wRVpGGcZdSEkUtQCr8T_imZpaUY27G0J1Xl5YIzayhThgjvpwoAdwQs-1ddmP8NTdW0PvOCnOk3WY5axEMMfvEkPUSlTSARH2oQY1Gz6JGlM25jggjN1X30Pa2zWfVVnB-pwoDiCw7qjS8dGR9sAyuUsvgARazZZ | 7 KB | — | ✓ | 3rd |
| https://kit.fontawesome.com/42fec296be.js | 0 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 · 4.7 MB · 844 KB savings availableFIX
~844.1 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 75 resources | 4.7 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization30 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
A+Text CompressionAll text resources are compressedPASS
A+Font Loading4 fonts (432 KB)PASS
Web fonts
4
432 KB total
Render-blocking
0
of 4
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- 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 ~198 KB and ~396 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
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 2073msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.epo.org www.epo.org | Other | 1531ms | 4 KB | — | €8/mo | Costly |
Matomo matomo.epo.org | Analytics | 1506ms | 65 KB | 43% | €8/mo | Costly |
www.epo.org www.epo.org | Other | 1274ms | 831 KB | 73% | €7/mo | Costly |
www.epo.org www.epo.org | Other | 934ms | 137 KB | 60% | €5/mo | Costly |
www.epo.org www.epo.org | Other | 685ms | 67 KB | — | €4/mo | Costly |
Unattributable Unattributable | Other | 644ms | 0 KB | — | €3/mo | Costly |
www.epo.org www.epo.org | Other | 229ms | 0 KB | — | €1/mo | Costly |
www.epo.org www.epo.org | Other | 229ms | 281 KB | — | €1/mo | Costly |
These scripts may cost more than they're worth
- www.epo.org adds 1531ms and costs ~€8/month
- Matomo adds 1506ms and costs ~€8/month
- www.epo.org adds 1274ms and costs ~€7/month
- www.epo.org adds 934ms and costs ~€5/month
- www.epo.org adds 685ms and costs ~€4/month
- Unattributable adds 644ms and costs ~€3/month
- www.epo.org adds 229ms and costs ~€1/month
- www.epo.org adds 229ms and costs ~€1/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.epo.org takes 1531ms 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
Matomo takes 1506ms 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.epo.org takes 1274ms 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
73% of www.epo.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
www.epo.org takes 934ms 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
60% of www.epo.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
www.epo.org takes 685ms 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 644ms 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.epo.org takes 229ms 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.epo.org takes 229ms 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