Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

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

Mobile Desktop

Performance

100

Accessibility

Best Practices

100

SEO

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

1.22 s

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

4.52 s

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

60 ms

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

0.000

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

2.64 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.

5.28 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

11 PASS 4 REVIEW

Image Optimization

12 images, 0 KB saveable

REVIEW

12 images, 0 KB saveable

All images are well-optimized

12 images 438 KB

0 oversized -0 KB

7 legacy format

0 missing dimensions CLS risk

JS Execution Cost

Action

1450ms total JS execution

REVIEW

1450ms total JS execution

https://www.bankofengland.co.uk/: 673ms CPU time

Unattributable: 306ms CPU time

https://www.bankofengland.co.uk/scripts/boe.vendor...: 241ms CPU time

https://www.bankofengland.co.uk/scripts/boe.min.js...: 159ms CPU time

https://s.go-mpulse.net/boomerang/9R3WH-S6EDC-8JGQ...: 71ms CPU time

Third-party scripts: 378ms (26% of total)

Main Thread Breakdown

Other 29% Script Evaluation 28% Style & Layout 25% Rendering 6% Script Parsing & Compilation 6% Parse HTML & CSS 6%

Script	Total	Scripting	Parse/Compile	Party
https://www.bankofengland.co.uk/	673ms	72ms	9ms	1st
Unattributable	306ms	8ms	0ms	3rd
https://www.bankofengland.co.uk/scripts/boe.vendor.min.js?ver=98f91	241ms	155ms	36ms	1st
https://www.bankofengland.co.uk/scripts/boe.min.js?ver=98f91	159ms	98ms	8ms	1st
https://s.go-mpulse.net/boomerang/9R3WH-S6EDC-8JGQW-55286-CGTTF	71ms	47ms	18ms	3rd

JS Bundles

5 scripts, 78 KB unused

REVIEW

5 scripts, 78 KB unused

https://www.bankofengland.co.uk/scripts/boe.vendor...: 39 KB unused (58%)

Consider code splitting or tree shaking to reduce unused code.

https://s.go-mpulse.net/boomerang/9R3WH-S6EDC-8JGQ...: 38 KB unused (66%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 78 KB

78 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://www.bankofengland.co.uk/scripts/boe.vendor.min.js?ver=98f91	68 KB	39 KB (58%)	✓	1st
https://s.go-mpulse.net/boomerang/9R3WH-S6EDC-8JGQW-55286-CGTTF	58 KB	38 KB (66%)	✓	3rd
https://www.bankofengland.co.uk/scripts/boe.min.js?ver=98f91	17 KB	—	✓	1st
https://www.bankofengland.co.uk/-/media/css/search-bundle-script.js?ver=BB56DD&mode=npe	27 KB	—	✓	1st
https://www.bankofengland.co.uk/-/media/css/search-new-js.js?ver=6AFCD3&mode=npe	2 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

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

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

Page Weight Budget

782 KB transferred, 36 requests

PASS

782 KB transferred, 36 requests

Page weighs 1.7 MB (782 KB transferred)

36 HTTP requests

Estimated 0.16 g CO2 per page load

782 KB transferred

36 requests

0.16 g CO2 per page load

Images 437.8 KiB 56%

JavaScript 171.8 KiB 22%

Fonts 78.9 KiB 10%

CSS 63.0 KiB 8%

Other 15.8 KiB 2%

HTML 14.7 KiB 2%

Other 214 B 0%

0 2.4 MB 4.9 MB

Under budget

A+

Third-Party Impact

7% third-party, 0 ms blocking

PASS

7% third-party, 0 ms blocking

Third-party code accounts for 7% of page weight (58.2 KiB of 782.3 KiB)

Third-party blocking time is low (0 ms)

93%

First-party Third-party

A+

Text Compression

All text resources are compressed

PASS

All text resources are compressed

All text resources are properly compressed.

A+

Font Loading

2 fonts (79 KB)

PASS

2 fonts (79 KB)

2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

79 KB total

Render-blocking

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

GilroyForBOE-Bold.woff woff swap

Size 42 KB

Load time 17 ms

Start 40 ms

Risk FOUT — text flashes from fallback to web font

Convert to woff2 for ~30% smaller file size

GilroyForBOE-Regular.woff2 woff2 swap

Size 37 KB

Load time 38 ms

Start 41 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)

Fixing the unchecked items could save ~13 KB and ~26 ms

A+

Resource Caching

All resources properly cached

PASS

All resources properly cached

No caching issues found

All static resources have appropriate caching headers.

A+

Critical Rendering Path

No render-blocking resources

PASS

No render-blocking resources

No render-blocking resources detected

A+

Resource Hints

No optimization needed

PASS

No optimization needed

No resource hint issues

A+

Page Weight Inventory

36 resources · 782 KB · 78 KB savings available

PASS

36 resources · 782 KB · 78 KB savings available

Within 1MB page-weight target

Got: 782 KB

~78 KB of savings available

17 third-party resources (7% of weight)

1 resources over 200KB

36 resources · 782.3 KiB · 17 third-party Within 1MB page-weight target

Image 58% · 453.6 KiB

JavaScript 22% · 171.8 KiB

Font 10% · 78.9 KiB

CSS 8% · 63.0 KiB

Document 2% · 14.7 KiB

Other 0% · 214 B

~77.6 KiB of savings available

Remove unused JavaScript: 77.6 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

36 resources			782.3 KiB

A+

Render-Blocking Resources

No render-blocking resources detected

PASS

No render-blocking resources detected

No render-blocking resources detected in <head>

A+

Third-Party Resources

No third-party resources detected

PASS

No third-party resources detected

HTTP Caching

max-age=60 (1 minute)

PASS

max-age=60 (1 minute)

Cache-Control header is set

Got: max-age=60

Effective TTL: 1 minute (max-age=60)

No ETag or Last-Modified header

Conditional requests (304 Not Modified) are not possible without validators.

Cache-Control

max-age=60

Directive	Value	Meaning
max-age	60	Cache for 1 minute

Effective TTL: 60 seconds

Network Waterfall

36 requests over 509ms

INFO

HTML JavaScript CSS Images Fonts XHR/Fetch Other

Third-Party Script Cost

Per-script blocking time, transfer cost, and cache headers

INFO

26% of JavaScript execution is third-party

First-party Third-party 378ms · 58KB · £4/mo

Script	Category	Execution	Transfer	Unused	Monthly Cost	Verdict
Unattributable Unattributable	Other	306ms	0 KB	—	£3/mo	Costly
s.go-mpulse.net s.go-mpulse.net	Other	71ms	58 KB	66%	£1/mo	Optional

Unattributable

Other

Costly

Execution 306ms

Transfer 0 KB

Monthly Cost £3/mo

s.go-mpulse.net

Other

Optional

Execution 71ms

Transfer 58 KB

Unused 66%

Monthly Cost £1/mo

These scripts may cost more than they're worth

Unattributable adds 306ms and costs ~£3/month

Unattributable takes 306ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

66% of s.go-mpulse.net's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

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.

Browse & Analyze

Learn

Performance

Page Load Progression

Green Hosting

Font loading timeline

Optimization checklist

These scripts may cost more than they're worth