Skip to content
https://citizensadvice.org.uk

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
94
GRADE
A
FIX
2
REVIEW
1
PASS
10
INFO
1

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

Mobile Desktop
100
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
100
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.
100
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.

536 ms

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

728 ms

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.

0.006

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

536 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.

728 ms

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
14
10 PASS 1 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 (145.3 KiB of 145.6 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.

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

Green Hosting

No green hosting detected

A+
Page Weight Budget
146 KB transferred, 15 requests
PASS
146 KB transferred, 15 requests
Info::
Page weighs 440 KB (146 KB transferred)
Info::
15 HTTP requests
Info::
Estimated 0.03 g CO2 per page load
146 KB / 2.4 MB budget
146 KB transferred
15 requests
0.03 g CO2 per page load
JavaScript 58.0 KiB 40%
Fonts 33.0 KiB 23%
CSS 24.1 KiB 17%
Other 17.1 KiB 12%
HTML 8.6 KiB 6%
Images 4.8 KiB 3%
0 2.4 MB 4.9 MB
Under budget
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
Image Optimization
4 images, 0 KB saveable
PASS
4 images, 0 KB saveable
Warning::
https://www.fundraisingregulator.org.uk/fr-badge/6... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
4 images 5 KB
0 oversized -0 KB
1 legacy format
1 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

A+
JS Execution Cost
No JS execution data
PASS
No JS execution data
Info::
No significant JS execution detected

Main Thread Breakdown

Style & Layout 33% Other 31% Script Evaluation 20% Parse HTML & CSS 5% Script Parsing & Compilation 5% Rendering 5%
A+
Font Loading
2 fonts (33 KB)
PASS
2 fonts (33 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

33 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 536 ms LCP 728 mshttps://www.citizensadvice.org.uk/assets/citizens_advice_components/open-sans-v26-latin-700-c12de74c75388b99217911061da4f485071392d528338b1f7052007ac0eb396b.woff2open-sans-v26-latin-700... https://www.citizensadvice.org.uk/assets/citizens_advice_components/open-sans-v26-latin-700-c12de74c75388b99217911061da4f485071392d528338b1f7052007ac0eb396b.woff2 — 16.3 KiB — 6 ms — font-display: swaphttps://www.citizensadvice.org.uk/assets/citizens_advice_components/open-sans-v26-latin-regular-2d8f2b8387a095f3e77a79e59b6026ce3ec5a3f02a62ffafd652496d0e331006.woff2open-sans-v26-latin-reg... https://www.citizensadvice.org.uk/assets/citizens_advice_components/open-sans-v26-latin-regular-2d8f2b8387a095f3e77a79e59b6026ce3ec5a3f02a62ffafd652496d0e331006.woff2 — 16.7 KiB — 6 ms — font-display: swap
open-sans-v26-latin-700... woff2 swap
Size 16 KB
Load time 6 ms
Start 160 ms
Risk FOUT — text flashes from fallback to web font
open-sans-v26-latin-reg... woff2 swap
Size 17 KB
Load time 6 ms
Start 160 ms
Risk FOUT — text flashes from fallback to web font
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+
JS Bundles
5 scripts, 0 KB unused
PASS
5 scripts, 0 KB unused
0 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.citizensadvice.org.uk/assets/citizens_advice_cookie_preferences/application-190ad337d2da8b75bdbac17369f1a530173572d48ab39634aed143910b4c0421.js2 KB—✓3rd
https://www.citizensadvice.org.uk/assets/polyfill-888987f7030a40d2ba92963038d6e451452f337a36e1688ebb55057600318afe.js47 KB—✓3rd
https://www.citizensadvice.org.uk/assets/public-homepage-e57be2fa2dacb646332889557bf0efa9c9e79d68011bbe433a19a853b306492d.js5 KB—✓3rd
https://www.citizensadvice.org.uk/assets/connect-prod-training-13cda6c3e135e8130e366f13aabfaa5c6b1856b4110705654a0715f8a97b6cf1.js2 KB—✓3rd
https://www.citizensadvice.org.uk/assets/connect-prod-55ea73a6b62b5bf4775792882f06044975a5d6c341392c3561a9b3dc4873a8c7.js2 KB—✓3rd
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
15 resources · 146 KB · 0 KB savings available
PASS
15 resources · 146 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 146 KB
Warning::
14 third-party resources (100% of weight)
15 resources · 145.6 KiB · 14 third-party Within 1MB page-weight target
JavaScript 40% · 58.0 KiB
Font 23% · 33.0 KiB
CSS 17% · 24.1 KiB
Image 15% · 21.7 KiB
Document 6% · 8.6 KiB
Other 0% · 252 B
Network Waterfall
15 requests over 233ms
INFO
0 ms 200 ms 400 ms 600 ms FCP 536 ms LCP 728 mshttps://citizensadvice.org.uk// https://citizensadvice.org.uk/ — 301 — 252 B — 50 ms — h2https://www.citizensadvice.org.uk/www.citizensadvice.org.uk/ https://www.citizensadvice.org.uk/ — 200 — 8.6 KiB — 41 ms — h2https://www.citizensadvice.org.uk/assets/public-homepage-d37d73d773de021a364144e6ed12a17e57272e01c93f1765d7d577125318350b.csswww.citizensadvice.org.uk/assets/pu... https://www.citizensadvice.org.uk/assets/public-homepage-d37d73d773de021a364144e6ed12a17e57272e01c93f1765d7d577125318350b.css — 200 — 24.1 KiB — 9 ms — h2https://www.citizensadvice.org.uk/assets/citizens_advice_cookie_preferences/application-190ad337d2da8b75bdbac17369f1a530173572d48ab39634aed143910b4c0421.jswww.citizensadvice.org.uk/assets/ci... https://www.citizensadvice.org.uk/assets/citizens_advice_cookie_preferences/application-190ad337d2da8b75bdbac17369f1a530173572d48ab39634aed143910b4c0421.js — 200 — 1.7 KiB — 8 ms — h2https://www.fundraisingregulator.org.uk/fr-badge/6d8352f2-d995-4eea-bb60-a28c2dc8d842/en/blackwww.fundraisingregulator.org.uk/fr-... https://www.fundraisingregulator.org.uk/fr-badge/6d8352f2-d995-4eea-bb60-a28c2dc8d842/en/black — 200 — 4.8 KiB — 62 ms — h3https://www.citizensadvice.org.uk/assets/polyfill-888987f7030a40d2ba92963038d6e451452f337a36e1688ebb55057600318afe.jswww.citizensadvice.org.uk/assets/po... https://www.citizensadvice.org.uk/assets/polyfill-888987f7030a40d2ba92963038d6e451452f337a36e1688ebb55057600318afe.js — 200 — 46.7 KiB — 15 ms — h2https://www.citizensadvice.org.uk/assets/public-homepage-e57be2fa2dacb646332889557bf0efa9c9e79d68011bbe433a19a853b306492d.jswww.citizensadvice.org.uk/assets/pu... https://www.citizensadvice.org.uk/assets/public-homepage-e57be2fa2dacb646332889557bf0efa9c9e79d68011bbe433a19a853b306492d.js — 200 — 4.6 KiB — 14 ms — h2https://www.citizensadvice.org.uk/assets/connect-prod-training-13cda6c3e135e8130e366f13aabfaa5c6b1856b4110705654a0715f8a97b6cf1.jswww.citizensadvice.org.uk/assets/co... https://www.citizensadvice.org.uk/assets/connect-prod-training-13cda6c3e135e8130e366f13aabfaa5c6b1856b4110705654a0715f8a97b6cf1.js — 200 — 2.5 KiB — 10 ms — h2https://www.citizensadvice.org.uk/assets/connect-prod-55ea73a6b62b5bf4775792882f06044975a5d6c341392c3561a9b3dc4873a8c7.jswww.citizensadvice.org.uk/assets/co... https://www.citizensadvice.org.uk/assets/connect-prod-55ea73a6b62b5bf4775792882f06044975a5d6c341392c3561a9b3dc4873a8c7.js — 200 — 2.5 KiB — 12 ms — h2data:image/svg+xml,<svg width="415" height="245" viewBox="0 0 415 245" fill="none" xmlns="http://ww…ww… data:image/svg+xml,<svg width="415" height="245" viewBox="0 0 415 245" fill="none" xmlns="http://ww… — 200 — 0 B — 0 ms — datadata:image/svg+xml,%3Csvg id='Layer_1' data-name='Layer 1' xmlns='http://www.w3.org/2000/svg' viewB…www.w3.org/2000/svg' viewB… data:image/svg+xml,%3Csvg id='Layer_1' data-name='Layer 1' xmlns='http://www.w3.org/2000/svg' viewB… — 200 — 0 B — 0 ms — datadata:image/svg+xml,<svg width="280" height="167" viewBox="0 0 280 167" fill="none" xmlns="http://ww…ww… data:image/svg+xml,<svg width="280" height="167" viewBox="0 0 280 167" fill="none" xmlns="http://ww… — 200 — 0 B — 0 ms — datahttps://www.citizensadvice.org.uk/assets/citizens_advice_components/open-sans-v26-latin-700-c12de74c75388b99217911061da4f485071392d528338b1f7052007ac0eb396b.woff2www.citizensadvice.org.uk/assets/ci... https://www.citizensadvice.org.uk/assets/citizens_advice_components/open-sans-v26-latin-700-c12de74c75388b99217911061da4f485071392d528338b1f7052007ac0eb396b.woff2 — 200 — 16.3 KiB — 6 ms — h2https://www.citizensadvice.org.uk/assets/citizens_advice_components/open-sans-v26-latin-regular-2d8f2b8387a095f3e77a79e59b6026ce3ec5a3f02a62ffafd652496d0e331006.woff2www.citizensadvice.org.uk/assets/ci... https://www.citizensadvice.org.uk/assets/citizens_advice_components/open-sans-v26-latin-regular-2d8f2b8387a095f3e77a79e59b6026ce3ec5a3f02a62ffafd652496d0e331006.woff2 — 200 — 16.7 KiB — 6 ms — h2https://www.citizensadvice.org.uk/favicon.icowww.citizensadvice.org.uk/favicon.i... https://www.citizensadvice.org.uk/favicon.ico — 200 — 16.9 KiB — 42 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

Send Feedback