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Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
74
GRADE
C
FIX
5
REVIEW
1
PASS
8
INFO
2

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

Mobile Desktop
40
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
95
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
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.

6.20 s

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

16.53 s

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

835 ms

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

0.009

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

6.45 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.

16.99 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
16
8 PASS 1 REVIEW 5 FIX
F
Page Weight Budget
Action
2.9 MB transferred, 157 requests
FIX
2.9 MB transferred, 157 requests
Warning::
Page weighs 6.9 MB (2.9 MB transferred)
Warning::
Images are 1.5 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 1.5 MB
Warning::
JavaScript is 934 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 934 KB
Info::
Fonts are 287 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 287 KB
Warning::
157 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 0.62 g CO2 per page load
2.9 MB / 2.4 MB budget
2.9 MB transferred
157 requests
0.62 g CO2 per page load
Images 1.5 MiB 51%
JavaScript 933.9 KiB 31%
Fonts 286.7 KiB 10%
CSS 102.1 KiB 3%
Other 52.4 KiB 2%
HTML 42.6 KiB 1%
Other 35.8 KiB 1%
Other 8.2 KiB 0%
Other 2.9 KiB 0%
Other 1.8 KiB 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over budget

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Why this matters

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.

Why this matters

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.

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

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

D
Third-Party Impact
Action
79% third-party, 0 ms blocking
FIX
79% third-party, 0 ms blocking
Warning::
Third-party code accounts for 79% of page weight (2.3 MiB of 2.9 MiB)
Info::
Third-party blocking time is low (0 ms)
21%
79%
First-party Third-party
F
JS Execution Cost
Action
3787ms total JS execution
FIX
3787ms total JS execution
Warning::
Unattributable: 839ms CPU time
Warning::
https://consent-manager.ft.com/Notice.8f529.js: 461ms CPU time
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-NWQ...: 367ms CPU time
Warning::
https://www.ft.com/__assets/hashed/page-kit/financ...: 315ms CPU time
Info::
https://consent-manager.ft.com/unified/wrapperMess...: 248ms CPU time
Warning::
Third-party scripts: 2878ms (76% of total)

Main Thread Breakdown

Script Evaluation 48% Other 22% Style & Layout 13% Script Parsing & Compilation 10% Parse HTML & CSS 3%
ScriptTotalScriptingParse/CompileParty
Unattributable839ms82ms0ms3rd
https://consent-manager.ft.com/Notice.8f529.js461ms331ms44ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-NWQJW68367ms280ms56ms3rd
https://www.ft.com/__assets/hashed/page-kit/financial-times-o-header.e39ceb699fee.bundle.js315ms2ms1ms1st
https://consent-manager.ft.com/unified/wrapperMessagingWithoutDetection.js248ms146ms13ms3rd
https://www.ft.com/242ms34ms6ms1st
https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604020101/pubads_impl.js209ms128ms68ms3rd
https://www.ft.com/__assets/hashed/page-kit/301.ca2546bf8793.bundle.js204ms148ms42ms1st
https://bloomreach.ft.com/js/exponea.min.js158ms137ms13ms3rd
https://www.ft.com/__assets/hashed/page-kit/scripts.0676687ff842.bundle.js148ms142ms5ms1st

Showing top 10 of 16 scripts

D
JS Bundles
Action
44 scripts, 365 KB unused
FIX
44 scripts, 365 KB unused
Warning::
https://securepubads.g.doubleclick.net/pagead/mana...: 140 KB unused (76%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-NWQ...: 75 KB unused (43%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.ft.com/__assets/hashed/page-kit/301.ca...: 68 KB unused (70%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://consent-manager.ft.com/Notice.8f529.js: 61 KB unused (68%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://consent-manager.ft.com/unified/4.40.1/usna...: 21 KB unused (52%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 365 KB
365 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604020101/pubads_impl.js183 KB140 KB (76%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-NWQJW68175 KB75 KB (43%)✓3rd
https://www.ft.com/__assets/hashed/page-kit/301.ca2546bf8793.bundle.js98 KB68 KB (70%)✓1st
https://consent-manager.ft.com/Notice.8f529.js91 KB61 KB (68%)✓3rd
https://consent-manager.ft.com/unified/4.40.1/usnat.f12613136193900e32e2.bundle.js42 KB21 KB (52%)✓3rd
https://www.ft.com/__assets/hashed/page-kit/financial-times-o-private-foundation.ad9ee90944ee.bundle.js1 KB—✓1st
https://www.ft.com/__assets/hashed/page-kit/financial-times-ft-date-format.7c516a24dccf.bundle.js2 KB—✓1st
https://www.ft.com/__assets/hashed/page-kit/financial-times-o-tracking.c6bb16738fa7.bundle.js7 KB—✓1st
https://www.ft.com/__assets/hashed/page-kit/financial-times-n-syndication.d2a7fe309e84.bundle.js8 KB—✓1st
https://www.ft.com/__assets/hashed/page-kit/financial-times-o-header.e39ceb699fee.bundle.js4 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

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

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
Image Optimization
Action
52 images, 0 KB saveable
REVIEW
52 images, 0 KB saveable
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.ft.com/__origami/service/image/v2/imag... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
52 images 1.5 MB
0 oversized -0 KB
26 legacy format
16 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

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

Set explicit width and height to prevent CLS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

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

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

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

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

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+
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+
Font Loading
6 fonts (287 KB)
PASS
6 fonts (287 KB)
Info::
6 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

6

287 KB total

Render-blocking

0

of 6

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s 12.0 s 14.0 s 16.0 s FCP 6.2 s LCP 16.5 shttps://www.ft.com/__origami/service/build/v3/font?version=1.13&font_name=Metric2-VF&system_code=origami&font_format=woff2font https://www.ft.com/__origami/service/build/v3/font?version=1.13&font_name=Metric2-VF&system_code=origami&font_format=woff2 — 120.6 KiB — 0 ms — font-display: swaphttps://www.ft.com/__origami/service/build/v3/font?version=1.13&font_name=FinancierDisplay-VF&system_code=origami&font_format=woff2font https://www.ft.com/__origami/service/build/v3/font?version=1.13&font_name=FinancierDisplay-VF&system_code=origami&font_format=woff2 — 63.9 KiB — 0 ms — font-display: swaphttps://www.ft.com/__origami/service/build/v3/font?font_format=woff2&font_name=MetricWeb-Semibold&system_code=origami&version=1.12font https://www.ft.com/__origami/service/build/v3/font?font_format=woff2&font_name=MetricWeb-Semibold&system_code=origami&version=1.12 — 0 B — 0 ms — font-display: swaphttps://www.ft.com/__origami/service/build/v3/font?font_format=woff2&font_name=MetricWeb-Regular&system_code=origami&version=1.12font https://www.ft.com/__origami/service/build/v3/font?font_format=woff2&font_name=MetricWeb-Regular&system_code=origami&version=1.12 — 0 B — 0 ms — font-display: swaphttps://www.ft.com/__origami/service/build/v3/font?font_format=woff&font_name=MetricWeb-Regular&system_code=origami&version=1.12font https://www.ft.com/__origami/service/build/v3/font?font_format=woff&font_name=MetricWeb-Regular&system_code=origami&version=1.12 — 50.5 KiB — 0 ms — font-display: swaphttps://www.ft.com/__origami/service/build/v3/font?font_format=woff&font_name=MetricWeb-Semibold&system_code=origami&version=1.12font https://www.ft.com/__origami/service/build/v3/font?font_format=woff&font_name=MetricWeb-Semibold&system_code=origami&version=1.12 — 51.7 KiB — 0 ms — font-display: swap
font woff2 swap
Size 121 KB
Load time 0 ms
Start 0 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
font woff2 swap
Size 64 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
font unknown swap
Size 0 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
font unknown swap
Size 0 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
font woff swap
Size 50 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
font woff swap
Size 52 KB
Load time 0 ms
Start 0 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 ~91 KB and ~182 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+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
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
157 requests over 0ms
INFO

Performance analysis not available for this result.

Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
76% of JavaScript execution is third-party
First-party Third-party 2878ms · 700KB · £30/mo
Unattributable
Other
Costly
Execution 839ms
Transfer 0 KB
Monthly Cost £9/mo
consent-manager.ft.com
Other
Costly
Execution 461ms
Transfer 91 KB
Unused 68%
Monthly Cost £5/mo
Google Tag Manager
Tag Manager
Costly
Execution 367ms
Transfer 175 KB
Unused 43%
Monthly Cost £4/mo
consent-manager.ft.com
Other
Costly
Execution 248ms
Transfer 42 KB
Monthly Cost £3/mo
securepubads.g.doubleclick.net
Other
Costly
Execution 209ms
Transfer 183 KB
Unused 76%
Monthly Cost £2/mo
bloomreach.ft.com
Other
Optional
Execution 158ms
Transfer 52 KB
Monthly Cost £2/mo
consent-manager.ft.com
Other
Optional
Execution 144ms
Transfer 42 KB
Unused 52%
Monthly Cost £1/mo
static.chartbeat.com
Other
Optional
Execution 139ms
Transfer 16 KB
Monthly Cost £1/mo
cdn.brandmetrics.com
Other
Optional
Execution 104ms
Transfer 29 KB
Monthly Cost £1/mo
securepubads.g.doubleclick.net
Other
Optional
Execution 89ms
Transfer 34 KB
Monthly Cost £1/mo
consent-notice.ft.com
Other
Optional
Execution 62ms
Transfer 8 KB
Monthly Cost £1/mo
consent-manager.ft.com
Other
Optional
Execution 59ms
Transfer 29 KB
Monthly Cost £1/mo

These scripts may cost more than they're worth

  • Unattributable adds 839ms and costs ~£9/month
  • consent-manager.ft.com adds 461ms and costs ~£5/month
  • Google Tag Manager adds 367ms and costs ~£4/month
  • consent-manager.ft.com adds 248ms and costs ~£3/month
  • securepubads.g.doubleclick.net adds 209ms and costs ~£2/month

76% 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

Unattributable takes 839ms 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

consent-manager.ft.com takes 461ms 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

68% of consent-manager.ft.com'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

Google Tag Manager takes 367ms 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

consent-manager.ft.com takes 248ms 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

securepubads.g.doubleclick.net takes 209ms 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

76% of securepubads.g.doubleclick.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

52% of consent-manager.ft.com'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.

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