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https://ico.org.uk

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
93
GRADE
A
FIX
1
REVIEW
2
PASS
10
INFO
1

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

Mobile Desktop
90
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.
92
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.

294 ms

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

854 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.

0.191

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

631 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.

855 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 2 REVIEW 1 FIX
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
Third-Party Impact
46% third-party, 0 ms blocking
REVIEW
46% third-party, 0 ms blocking
Info::
Third-party code accounts for 46% of page weight (93.5 KiB of 201.2 KiB)
Info::
Third-party blocking time is low (0 ms)
54%
46%
First-party Third-party
B
Image Optimization
18 images, 0 KB saveable
REVIEW
18 images, 0 KB saveable
Info::
All images are well-optimized
18 images 43 KB
0 oversized -0 KB
8 legacy format
0 missing dimensions CLS risk
A+
Page Weight Budget
201 KB transferred, 25 requests
PASS
201 KB transferred, 25 requests
Info::
Page weighs 605 KB (201 KB transferred)
Info::
25 HTTP requests
Info::
Estimated 0.04 g CO2 per page load
201 KB / 2.4 MB budget
201 KB transferred
25 requests
0.04 g CO2 per page load
JavaScript 105.1 KiB 52%
Images 42.8 KiB 21%
CSS 25.3 KiB 13%
Fonts 17.2 KiB 9%
HTML 9.3 KiB 5%
Other 935 B 0%
Other 610 B 0%
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+
JS Execution Cost
No JS execution data
PASS
No JS execution data
Info::
No significant JS execution detected

Main Thread Breakdown

Other 31% Script Evaluation 30% Style & Layout 24% Rendering 6% Script Parsing & Compilation 5% Parse HTML & CSS 4%
A+
Font Loading
1 fonts (17 KB)
PASS
1 fonts (17 KB)
Info::
1 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

1

17 KB total

Render-blocking

0

of 1

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 294 ms LCP 854 mshttps://ico.org.uk/fonts/icons-default.ttf?w9uwepicons-default.ttf https://ico.org.uk/fonts/icons-default.ttf?w9uwep — 17.2 KiB — 26 ms — font-display: swap
icons-default.ttf ttf swap
Size 17 KB
Load time 26 ms
Start 205 ms
Risk FOUT — text flashes from fallback to web font
  • 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 ~5 KB and ~10 ms

A+
JS Bundles
2 scripts, 42 KB unused
PASS
2 scripts, 42 KB unused
Warning::
https://cc.cdn.civiccomputing.com/9/cookieControl-...: 42 KB unused (46%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 42 KB
42 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://cc.cdn.civiccomputing.com/9/cookieControl-9.9.min.js93 KB42 KB (46%)✓3rd
https://ico.org.uk/js/index.js?v=lzVtN7n9HO9sYcg02GpHp-tXu9pXXxBMG3QvE9_Dloc12 KB—✓1st

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

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
25 resources · 201 KB · 42 KB savings available
PASS
25 resources · 201 KB · 42 KB savings available
Info::
Within 1MB page-weight target
Got: 201 KB
Warning::
2 third-party resources (46% of weight)
25 resources · 201.2 KiB · 2 third-party Within 1MB page-weight target
JavaScript 52% · 105.1 KiB
Image 22% · 43.8 KiB
CSS 13% · 25.3 KiB
Font 9% · 17.2 KiB
Document 5% · 9.3 KiB
Other 0% · 610 B

~42.4 KiB of savings available

Remove unused JavaScript: 42.4 KiB
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Network Waterfall
25 requests over 412ms
INFO
0 ms 200 ms 400 ms 600 ms 800 ms FCP 294 ms LCP 854 mshttps://ico.org.uk// https://ico.org.uk/ — 200 — 9.3 KiB — 136 ms — h2https://ico.org.uk/css/site.css?v=BwOVC9vVV6268LypYZd3tkCsM63Es5d1IY4UaqUcee8/css/site.css?v=BwOVC9vVV6268LypYZd... https://ico.org.uk/css/site.css?v=BwOVC9vVV6268LypYZd3tkCsM63Es5d1IY4UaqUcee8 — 200 — 25.3 KiB — 33 ms — h2https://ico.org.uk/media2/qkcg1rdf/logo-small.svg?width=80&height=32&v=1db03b868bf60c0/media2/qkcg1rdf/logo-small.svg?wid... https://ico.org.uk/media2/qkcg1rdf/logo-small.svg?width=80&height=32&v=1db03b868bf60c0 — 200 — 908 B — 31 ms — h2https://ico.org.uk/media2/myukqaa2/ico-header-logo.svg?width=160&height=96&v=1db03b866f17e90/media2/myukqaa2/ico-header-logo.sv... https://ico.org.uk/media2/myukqaa2/ico-header-logo.svg?width=160&height=96&v=1db03b866f17e90 — 200 — 2.7 KiB — 30 ms — h2https://cc.cdn.civiccomputing.com/9/cookieControl-9.9.min.jscc.cdn.civiccomputing.com/9/cookieC... https://cc.cdn.civiccomputing.com/9/cookieControl-9.9.min.js — 200 — 92.9 KiB — 145 ms — h3https://ico.org.uk/js/index.js?v=lzVtN7n9HO9sYcg02GpHp-tXu9pXXxBMG3QvE9_Dloc/js/index.js?v=lzVtN7n9HO9sYcg02GpH... https://ico.org.uk/js/index.js?v=lzVtN7n9HO9sYcg02GpHp-tXu9pXXxBMG3QvE9_Dloc — 200 — 12.1 KiB — 28 ms — h2https://ico.org.uk/media2/3e3molj2/x-logo-1.svg?width=24&height=24&v=1db7d782a8d9170/media2/3e3molj2/x-logo-1.svg?width... https://ico.org.uk/media2/3e3molj2/x-logo-1.svg?width=24&height=24&v=1db7d782a8d9170 — 200 — 594 B — 30 ms — h2https://ico.org.uk/media2/z3vdkkxj/youtube.svg?width=24&height=24&v=1db042ab32beee0/media2/z3vdkkxj/youtube.svg?width=... https://ico.org.uk/media2/z3vdkkxj/youtube.svg?width=24&height=24&v=1db042ab32beee0 — 200 — 772 B — 31 ms — h2https://ico.org.uk/media2/cgdpvn4n/linkedin.svg?width=24&height=24&v=1db042ab2dda7d0/media2/cgdpvn4n/linkedin.svg?width... https://ico.org.uk/media2/cgdpvn4n/linkedin.svg?width=24&height=24&v=1db042ab2dda7d0 — 200 — 747 B — 34 ms — h2https://ico.org.uk/media2/g2nhkyjv/facebook.svg?width=24&height=24&v=1db03b86b4b62d0/media2/g2nhkyjv/facebook.svg?width... https://ico.org.uk/media2/g2nhkyjv/facebook.svg?width=24&height=24&v=1db03b86b4b62d0 — 200 — 649 B — 32 ms — h2https://ico.org.uk/media2/thzeryz5/envelope.svg?width=24&height=24&v=1db03b86a1d4310/media2/thzeryz5/envelope.svg?width... https://ico.org.uk/media2/thzeryz5/envelope.svg?width=24&height=24&v=1db03b86a1d4310 — 200 — 848 B — 32 ms — h2https://ico.org.uk/media2/r34b3hma/ogl.png?width=40&height=16&v=1dc6f3b2af11af0/media2/r34b3hma/ogl.png?width=40&h... https://ico.org.uk/media2/r34b3hma/ogl.png?width=40&height=16&v=1dc6f3b2af11af0 — 200 — 720 B — 28 ms — h2https://ico.org.uk/fonts/icons-default.ttf?w9uwep/fonts/icons-default.ttf?w9uwep https://ico.org.uk/fonts/icons-default.ttf?w9uwep — 200 — 17.2 KiB — 26 ms — h2https://apikeys.civiccomputing.com/c/v?d=ico.org.uk&p=CookieControl%20Single-Site&v=9&k=dbf86e044f3ab8c4df852af5c7c6ceb2dd7678dd&format=jsonapikeys.civiccomputing.com/c/v?d=ic... https://apikeys.civiccomputing.com/c/v?d=ico.org.uk&p=CookieControl%20Single-Site&v=9&k=dbf86e044f3ab8c4df852af5c7c6ceb2dd7678dd&format=json — 200 — 610 B — 50 ms — h3https://ico.org.uk/media2/jekcohbe/sotp-website-twitter-card-d-1.jpg?width=510&height=400&v=1dcc81525613bf0&format=webp/media2/jekcohbe/sotp-website-twitt... https://ico.org.uk/media2/jekcohbe/sotp-website-twitter-card-d-1.jpg?width=510&height=400&v=1dcc81525613bf0&format=webp — 200 — 6.5 KiB — 29 ms — h2https://ico.org.uk/media2/rmzfonwb/impact-homepage-link-graphic.png?width=100&height=100&v=1dc8af3780f58f0&format=webp/media2/rmzfonwb/impact-homepage-li... https://ico.org.uk/media2/rmzfonwb/impact-homepage-link-graphic.png?width=100&height=100&v=1dc8af3780f58f0&format=webp — 200 — 3.6 KiB — 31 ms — h2https://ico.org.uk/media2/i15jzjvi/sotp-homepage-link-graphic-b-0904.png?width=100&height=100&v=1dcc81524933d90&format=webp/media2/i15jzjvi/sotp-homepage-link... https://ico.org.uk/media2/i15jzjvi/sotp-homepage-link-graphic-b-0904.png?width=100&height=100&v=1dcc81524933d90&format=webp — 200 — 4.4 KiB — 30 ms — h2https://ico.org.uk/media2/migrated/2259011/ydm-access-180x180.gif?width=96&height=96&v=1db03b916558ca0&format=webp/media2/migrated/2259011/ydm-access... https://ico.org.uk/media2/migrated/2259011/ydm-access-180x180.gif?width=96&height=96&v=1db03b916558ca0&format=webp — 200 — 3.3 KiB — 37 ms — h2https://ico.org.uk/media2/migrated/2259127/ydm-official-information-180x180.gif?width=96&height=96&v=1db03b917e7ec70&format=webp/media2/migrated/2259127/ydm-offici... https://ico.org.uk/media2/migrated/2259127/ydm-official-information-180x180.gif?width=96&height=96&v=1db03b917e7ec70&format=webp — 200 — 3.3 KiB — 32 ms — h2https://ico.org.uk/media2/migrated/2259031/ydm-concern-180x180.gif?width=96&height=96&v=1db03b91a037970&format=webp/media2/migrated/2259031/ydm-concer... https://ico.org.uk/media2/migrated/2259031/ydm-concern-180x180.gif?width=96&height=96&v=1db03b91a037970&format=webp — 200 — 4.0 KiB — 33 ms — h2https://ico.org.uk/media2/migrated/4030917/ydm-social-media-180x180.png?width=96&height=96&v=1db03b9208ce7e0&format=webp/media2/migrated/4030917/ydm-social... https://ico.org.uk/media2/migrated/4030917/ydm-social-media-180x180.png?width=96&height=96&v=1db03b9208ce7e0&format=webp — 200 — 2.0 KiB — 38 ms — h2https://ico.org.uk/media2/xnlb3iea/data-use-and-access-180x180.jpg?width=96&height=96&v=1dbe1c28051a160&format=webp/media2/xnlb3iea/data-use-and-acces... https://ico.org.uk/media2/xnlb3iea/data-use-and-access-180x180.jpg?width=96&height=96&v=1dbe1c28051a160&format=webp — 200 — 2.3 KiB — 37 ms — h2https://ico.org.uk/media2/migrated/1316/laptop-180x180.jpg?width=96&height=96&v=1db34ae06838cc0&format=webp/media2/migrated/1316/laptop-180x18... https://ico.org.uk/media2/migrated/1316/laptop-180x180.jpg?width=96&height=96&v=1db34ae06838cc0&format=webp — 200 — 2.8 KiB — 34 ms — h2https://ico.org.uk/media2/migrated/1340/publication-180x180.jpg?width=96&height=96&v=1db34ae08f947b0&format=webp/media2/migrated/1340/publication-1... https://ico.org.uk/media2/migrated/1340/publication-180x180.jpg?width=96&height=96&v=1db34ae08f947b0&format=webp — 200 — 2.8 KiB — 30 ms — h2https://ico.org.uk/media2/lhphq55z/favicon.ico/media2/lhphq55z/favicon.ico https://ico.org.uk/media2/lhphq55z/favicon.ico — 200 — 935 B — 27 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.

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