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Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
86
GRADE
B
FIX
2
REVIEW
3
PASS
8
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
92
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
89
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
83
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

1.32 s

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

1.32 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

6 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.006

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

1.32 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.

2.15 s

Page Load Progression

375 ms
750 ms
1.1 s
1.5 s
1.9 s
2.2 s
2.6 s
3.0 s
Checks
15
8 PASS 3 REVIEW 2 FIX
D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (792.9 KiB of 792.9 KiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
HTTP Caching
Action
No cache headers
FIX
No cache headers
Warning::
No Cache-Control header found
Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.

No Cache-Control header

Adding a Cache-Control header can significantly improve repeat-visit performance.

B
Image Optimization
3 images, 0 KB saveable
REVIEW
3 images, 0 KB saveable
Warning::
https://docs.un.org/static/images/logo-en.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://docs.un.org/static/images/logo-en-reverse.... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
3 images 18 KB
0 oversized -0 KB
3 legacy format
2 missing dimensions CLS risk

Set explicit width and height to prevent CLS.

Why this matters

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.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

C
JS Bundles
Action
4 scripts, 186 KB unused
REVIEW
4 scripts, 186 KB unused
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-LQC...: 63 KB unused (46%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-TK9B...: 62 KB unused (40%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-E886...: 61 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 186 KB
186 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtm.js?id=GTM-LQCS138 KB63 KB (46%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-TK9BQL5X7Z&cx=c&gtm=4e64k0154 KB62 KB (40%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-E886RWKZCH148 KB61 KB (42%)✓3rd
https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/js/bootstrap.bundle.min.js24 KB—✓3rd

Consider code splitting or tree shaking to reduce unused code.

Why this matters

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.

Why this matters

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.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
Page Weight Budget
793 KB transferred, 18 requests
PASS
793 KB transferred, 18 requests
Info::
Page weighs 2.0 MB (793 KB transferred)
Info::
Fonts are 241 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 241 KB
Info::
18 HTTP requests
Info::
Estimated 0.16 g CO2 per page load
793 KB / 2.4 MB budget
793 KB transferred
18 requests
0.16 g CO2 per page load
JavaScript 464.2 KiB 59%
Fonts 240.9 KiB 30%
CSS 55.2 KiB 7%
Images 18.0 KiB 2%
Other 10.2 KiB 1%
HTML 3.8 KiB 0%
Other 594 B 0%
0 2.4 MB 4.9 MB
Under budget

Subset fonts to include only used characters, or switch to system font stacks.

Why this matters

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 Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+
JS Execution Cost
268ms total JS execution
PASS
268ms total JS execution
Info::
https://www.googletagmanager.com/gtag/js?id=G-E886...: 104ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-TK9B...: 58ms CPU time
Info::
https://www.googletagmanager.com/gtm.js?id=GTM-LQC...: 56ms CPU time
Info::
Unattributable: 51ms CPU time
Warning::
Third-party scripts: 268ms (100% of total)

Main Thread Breakdown

Script Evaluation 51% Script Parsing & Compilation 18% Other 18% Style & Layout 9% Parse HTML & CSS 4%
ScriptTotalScriptingParse/CompileParty
https://www.googletagmanager.com/gtag/js?id=G-E886RWKZCH104ms67ms36ms3rd
https://www.googletagmanager.com/gtag/js?id=G-TK9BQL5X7Z&cx=c&gtm=4e64k058ms47ms10ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-LQCS56ms44ms11ms3rd
Unattributable51ms1ms0ms3rd
A+
Font Loading
2 fonts (241 KB)
PASS
2 fonts (241 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

241 KB total

Render-blocking

0

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 1.3 s LCP 1.3 shttps://fonts.gstatic.com/s/materialicons/v145/flUhRq6tzZclQEJ-Vdg-IuiaDsNcIhQ8tQ.woff2flUhRq6tzZclQEJ-Vdg-Iui... https://fonts.gstatic.com/s/materialicons/v145/flUhRq6tzZclQEJ-Vdg-IuiaDsNcIhQ8tQ.woff2 — 125.6 KiB — 84 ms — font-display: swaphttps://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/webfonts/fa-brands-400.woff2fa-brands-400.woff2 https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/webfonts/fa-brands-400.woff2 — 115.3 KiB — 57 ms — font-display: swap
flUhRq6tzZclQEJ-Vdg-Iui... woff2 swap
Size 126 KB
Load time 84 ms
Start 756 ms
Risk FOUT — text flashes from fallback to web font
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
fa-brands-400.woff2 woff2 swap
Size 115 KB
Load time 57 ms
Start 756 ms
Risk FOUT — text flashes from fallback to web font
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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 ~120 KB and ~240 ms

A+
Resource Caching
All resources properly cached
PASS
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
No render-blocking resources detected
A+
Resource Hints
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
A
Page Weight Inventory
18 resources · 793 KB · 186 KB savings available
PASS
18 resources · 793 KB · 186 KB savings available
Info::
Within 1MB page-weight target
Got: 793 KB
Info::
~186 KB of savings available
Warning::
17 third-party resources (100% of weight)
18 resources · 792.9 KiB · 17 third-party Within 1MB page-weight target
JavaScript 59% · 464.2 KiB
Font 30% · 240.9 KiB
CSS 7% · 55.2 KiB
Image 4% · 28.1 KiB
Document 0% · 3.9 KiB
Other 0% · 594 B

~186.1 KiB of savings available

Remove unused JavaScript: 186.1 KiB
Network Waterfall
18 requests over 1225ms
INFO
0 ms 500 ms 1.0 s FCP 1.3 s LCP 1.3 shttps://undocs.org// https://undocs.org/ — 301 — 82 B — 297 ms — h2https://docs.un.org/docs.un.org/ https://docs.un.org/ — 200 — 3.8 KiB — 306 ms — h2https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.csscdnjs.cloudflare.com/ajax/libs/font... https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css — 200 — 19.1 KiB — 67 ms — h3https://fonts.googleapis.com/icon?family=Material+Iconsfonts.googleapis.com/icon?family=Ma... https://fonts.googleapis.com/icon?family=Material+Icons — 200 — 817 B — 96 ms — h2https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/css/bootstrap.min.csscdn.jsdelivr.net/npm/bootstrap@5.3.... https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/css/bootstrap.min.css — 200 — 27.2 KiB — 12 ms — h2https://docs.un.org/static/css/style.cssdocs.un.org/static/css/style.css https://docs.un.org/static/css/style.css — 200 — 8.1 KiB — 106 ms — h2https://docs.un.org/static/images/logo-en.svgdocs.un.org/static/images/logo-en.s... https://docs.un.org/static/images/logo-en.svg — 200 — 9.2 KiB — 205 ms — h2https://docs.un.org/static/images/logo-en-reverse.svgdocs.un.org/static/images/logo-en-r... https://docs.un.org/static/images/logo-en-reverse.svg — 200 — 8.7 KiB — 203 ms — h2https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/js/bootstrap.bundle.min.jscdn.jsdelivr.net/npm/bootstrap@5.3.... https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/js/bootstrap.bundle.min.js — 200 — 24.0 KiB — 6 ms — h2https://www.googletagmanager.com/gtag/js?id=G-E886RWKZCHwww.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=G-E886RWKZCH — 200 — 148.3 KiB — 165 ms — h2https://www.googletagmanager.com/gtm.js?id=GTM-LQCSwww.googletagmanager.com/gtm.js?id=... https://www.googletagmanager.com/gtm.js?id=GTM-LQCS — 200 — 138.3 KiB — 187 ms — h2https://fonts.gstatic.com/s/materialicons/v145/flUhRq6tzZclQEJ-Vdg-IuiaDsNcIhQ8tQ.woff2fonts.gstatic.com/s/materialicons/v... https://fonts.gstatic.com/s/materialicons/v145/flUhRq6tzZclQEJ-Vdg-IuiaDsNcIhQ8tQ.woff2 — 200 — 125.6 KiB — 84 ms — h3https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/webfonts/fa-brands-400.woff2cdnjs.cloudflare.com/ajax/libs/font... https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/webfonts/fa-brands-400.woff2 — 200 — 115.3 KiB — 57 ms — h3https://region1.google-analytics.com/g/collect?v=2&tid=G-E886RWKZCH&gtm=45je64k0v9201281592za200zd9201281592&_p=1776894454792&gcd=13l3l3l2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1971131374.1776894455&frm=0&pscdl=noapi&rcb=18&sr=800x600&uaa=x86&uab=64&uafvl=Chromium%3B147.0.7727.101%7CNot.A%252FBrand%3B8.0.0.0&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115616986~115938466~115938468~117266400~117512542&dp=%2F&dl=https%3A%2F%2Fdocs.un.org%2F&sid=1776894455&sct=1&seg=0&dt=UNDOCS&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=872region1.google-analytics.com/g/coll... https://region1.google-analytics.com/g/collect?v=2&tid=G-E886RWKZCH&gtm=45je64k0v9201281592za200zd9201281592&_p=1776894454792&gcd=13l3l3l2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1971131374.1776894455&frm=0&pscdl=noapi&rcb=18&sr=800x600&uaa=x86&uab=64&uafvl=Chromium%3B147.0.7727.101%7CNot.A%252FBrand%3B8.0.0.0&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115616986~115938466~115938468~117266400~117512542&dp=%2F&dl=https%3A%2F%2Fdocs.un.org%2F&sid=1776894455&sct=1&seg=0&dt=UNDOCS&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=872 — 204 — 546 B — 108 ms — h2https://www.googletagmanager.com/gtag/js?id=G-TK9BQL5X7Z&cx=c&gtm=4e64k0www.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=G-TK9BQL5X7Z&cx=c&gtm=4e64k0 — 200 — 153.6 KiB — 42 ms — h2https://region1.google-analytics.com/g/collect?v=2&tid=G-TK9BQL5X7Z&gtm=45je64k0v870000365z8539426za20gzb539426zd539426&_p=1776894454792&gcd=13l3lPl2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1971131374.1776894455&frm=0&pscdl=noapi&rcb=7&sr=800x600&tt=gtm_verified&uaa=x86&uab=64&uafvl=Chromium%3B147.0.7727.101%7CNot.A%252FBrand%3B8.0.0.0&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115938466~115938468~117266401~117512542~118463261&sid=1776894455&sct=1&seg=0&dl=https%3A%2F%2Fdocs.un.org%2F&dt=UNDOCS&en=page_view&_fv=1&_ss=1&ep.content_group=&ep.visitor_viewport=Large%20(1025px-1440px)%20%2F%20Tall%20(901px-1080px)&ep.un_page_language=English&tfd=1081region1.google-analytics.com/g/coll... https://region1.google-analytics.com/g/collect?v=2&tid=G-TK9BQL5X7Z&gtm=45je64k0v870000365z8539426za20gzb539426zd539426&_p=1776894454792&gcd=13l3lPl2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1971131374.1776894455&frm=0&pscdl=noapi&rcb=7&sr=800x600&tt=gtm_verified&uaa=x86&uab=64&uafvl=Chromium%3B147.0.7727.101%7CNot.A%252FBrand%3B8.0.0.0&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115938466~115938468~117266401~117512542~118463261&sid=1776894455&sct=1&seg=0&dl=https%3A%2F%2Fdocs.un.org%2F&dt=UNDOCS&en=page_view&_fv=1&_ss=1&ep.content_group=&ep.visitor_viewport=Large%20(1025px-1440px)%20%2F%20Tall%20(901px-1080px)&ep.un_page_language=English&tfd=1081 — 204 — 48 B — 37 ms — h2https://www.googletagmanager.com/td?id=G-TK9BQL5X7Z&v=3&t=t&pid=1514828169&gtm=45je64k0v870000365za20gzb539426zd539426&seq=1&exp=0~115938466~115938468~117266401~118463261&dl=docs.un.org%2F&tdp=G-TK9BQL5X7Z;70000365;1;6;0&frm=0&rtg=39426&slo=2&hlo=1&lst=1&pcid=39426&bt=0&ct=3&z=0www.googletagmanager.com/td?id=G-TK... https://www.googletagmanager.com/td?id=G-TK9BQL5X7Z&v=3&t=t&pid=1514828169&gtm=45je64k0v870000365za20gzb539426zd539426&seq=1&exp=0~115938466~115938468~117266401~118463261&dl=docs.un.org%2F&tdp=G-TK9BQL5X7Z;70000365;1;6;0&frm=0&rtg=39426&slo=2&hlo=1&lst=1&pcid=39426&bt=0&ct=3&z=0 — 204 — 18 B — 28 ms — h3https://docs.un.org/static/images/favicon.icodocs.un.org/static/images/favicon.i... https://docs.un.org/static/images/favicon.ico — 200 — 10.1 KiB — 105 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
100% of JavaScript execution is third-party
First-party Third-party 268ms · 440KB · €3/mo
Google Tag Manager
Tag Manager
Optional
Execution 104ms
Transfer 148 KB
Unused 42%
Monthly Cost €1/mo
Google Tag Manager
Tag Manager
Optional
Execution 58ms
Transfer 154 KB
Unused 40%
Monthly Cost €1/mo
Google Tag Manager
Tag Manager
Optional
Execution 56ms
Transfer 138 KB
Unused 46%
Monthly Cost €1/mo
Unattributable
Other
Optional
Execution 51ms
Transfer 0 KB
Monthly Cost €1/mo

100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.

Why this matters

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

How third-party costs are calculated

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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