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Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
95
GRADE
A
FIX
1
REVIEW
2
PASS
12
INFO
2

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

Mobile Desktop
99
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
76
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.

1.05 s

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

2.03 s

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.

0.015

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

1.05 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.

2.04 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
17
12 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.

C
Image Optimization
Action
13 images, 0 KB saveable
REVIEW
13 images, 0 KB saveable
Warning::
https://xdebug.cloud/assets/images/logo.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://xdebug.org/images/logos/b13.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://xdebug.org/images/logos/uconnect.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://xdebug.org/images/logos/io.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://xdebug.org/images/logos/xdebug-cloud.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://xdebug.org/images/logos/seidengroup.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://xdebug.org/images/logos/11com7.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://xdebug.org/images/logos/tideways.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://xdebug.org/images/logos/typo3.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://xdebug.org/images/logos/private-packagist.... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://xdebug.org/images/logos/vema.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://xdebug.org/images/logos/weCreate.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
13 images 70 KB
0 oversized -0 KB
13 legacy format
12 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

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

B
JS Execution Cost
846ms total JS execution
REVIEW
846ms total JS execution
Warning::
https://xdebug.org/: 505ms CPU time
Warning::
Unattributable: 341ms CPU time
Info::
Third-party scripts: 341ms (40% of total)

Main Thread Breakdown

Style & Layout 50% Other 40% Rendering 6%
ScriptTotalScriptingParse/CompileParty
https://xdebug.org/505ms7ms1ms1st
Unattributable341ms11ms0ms3rd
A+
Page Weight Budget
199 KB transferred, 22 requests
PASS
199 KB transferred, 22 requests
Info::
Page weighs 197 KB (199 KB transferred)
Info::
22 HTTP requests
Info::
Estimated 0.04 g CO2 per page load
199 KB / 2.4 MB budget
199 KB transferred
22 requests
0.04 g CO2 per page load
Fonts 99.9 KiB 50%
Images 70.0 KiB 35%
CSS 17.7 KiB 9%
HTML 8.8 KiB 4%
Other 2.2 KiB 1%
0 2.4 MB 4.9 MB
Under budget
A+
Third-Party Impact
5% third-party, 0 ms blocking
PASS
5% third-party, 0 ms blocking
Info::
Third-party code accounts for 5% of page weight (9.6 KiB of 198.5 KiB)
Info::
Third-party blocking time is low (0 ms)
95%
First-party Third-party
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 (100 KB)
PASS
6 fonts (100 KB)
Info::
6 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

6

100 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 500 ms 1.0 s 1.5 s 2.0 s FCP 1.1 s LCP 2.0 shttps://xdebug.org/fonts/IBMPlexMono-Regular-Latin1.woff2IBMPlexMono-Regular-Lat... https://xdebug.org/fonts/IBMPlexMono-Regular-Latin1.woff2 — 13.3 KiB — 11 ms — font-display: swaphttps://xdebug.org/fonts/IBMPlexSans-SemiBold-Latin1.woff2IBMPlexSans-SemiBold-La... https://xdebug.org/fonts/IBMPlexSans-SemiBold-Latin1.woff2 — 17.2 KiB — 11 ms — font-display: swaphttps://xdebug.org/fonts/IBMPlexSans-Regular-Latin1.woff2IBMPlexSans-Regular-Lat... https://xdebug.org/fonts/IBMPlexSans-Regular-Latin1.woff2 — 16.3 KiB — 13 ms — font-display: swaphttps://xdebug.org/fonts/IBMPlexSans-MediumItalic-Latin1.woff2IBMPlexSans-MediumItali... https://xdebug.org/fonts/IBMPlexSans-MediumItalic-Latin1.woff2 — 18.3 KiB — 12 ms — font-display: swaphttps://xdebug.org/fonts/IBMPlexSans-SemiBoldItalic-Latin1.woff2IBMPlexSans-SemiBoldIta... https://xdebug.org/fonts/IBMPlexSans-SemiBoldItalic-Latin1.woff2 — 17.9 KiB — 13 ms — font-display: swaphttps://xdebug.org/fonts/IBMPlexSans-Medium-Latin1.woff2IBMPlexSans-Medium-Lati... https://xdebug.org/fonts/IBMPlexSans-Medium-Latin1.woff2 — 16.9 KiB — 14 ms — font-display: swap
IBMPlexMono-Regular-Lat... woff2 swap
Size 13 KB
Load time 11 ms
Start 157 ms
Risk FOUT — text flashes from fallback to web font
IBMPlexSans-SemiBold-La... woff2 swap
Size 17 KB
Load time 11 ms
Start 184 ms
Risk FOUT — text flashes from fallback to web font
IBMPlexSans-Regular-Lat... woff2 swap
Size 16 KB
Load time 13 ms
Start 184 ms
Risk FOUT — text flashes from fallback to web font
IBMPlexSans-MediumItali... woff2 swap
Size 18 KB
Load time 12 ms
Start 189 ms
Risk FOUT — text flashes from fallback to web font
IBMPlexSans-SemiBoldIta... woff2 swap
Size 18 KB
Load time 13 ms
Start 190 ms
Risk FOUT — text flashes from fallback to web font
IBMPlexSans-Medium-Lati... woff2 swap
Size 17 KB
Load time 14 ms
Start 191 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
No JavaScript
PASS
No JavaScript
Info::
No JavaScript bundles
No JavaScript files loaded.
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
22 resources · 199 KB · 0 KB savings available
PASS
22 resources · 199 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 199 KB
Info::
2 third-party resources (5% of weight)
22 resources · 198.5 KiB · 2 third-party Within 1MB page-weight target
Font 50% · 99.9 KiB
Image 36% · 72.2 KiB
CSS 9% · 17.7 KiB
Document 4% · 8.8 KiB
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: Mythic Beasts Ltd

Network Waterfall
22 requests over 263ms
INFO
0 ms 500 ms 1.0 s 1.5 s 2.0 s FCP 1.1 s LCP 2.0 shttps://xdebug.org// https://xdebug.org/ — 200 — 8.8 KiB — 40 ms — h2https://xdebug.org/core2.css/core2.css https://xdebug.org/core2.css — 200 — 17.7 KiB — 12 ms — h2https://xdebug.cloud/assets/images/logo.svgxdebug.cloud/assets/images/logo.svg https://xdebug.cloud/assets/images/logo.svg — 200 — 8.0 KiB — 159 ms — h2https://xdebug.org/images/logos/11com7.svg/images/logos/11com7.svg https://xdebug.org/images/logos/11com7.svg — 200 — 2.4 KiB — 13 ms — h2https://xdebug.org/images/logos/b13.svg/images/logos/b13.svg https://xdebug.org/images/logos/b13.svg — 200 — 596 B — 23 ms — h2https://xdebug.org/images/logos/uconnect.svg/images/logos/uconnect.svg https://xdebug.org/images/logos/uconnect.svg — 200 — 2.6 KiB — 24 ms — h2https://xdebug.org/images/logos/io.svg/images/logos/io.svg https://xdebug.org/images/logos/io.svg — 200 — 1004 B — 27 ms — h2https://xdebug.org/images/logos/tideways.svg/images/logos/tideways.svg https://xdebug.org/images/logos/tideways.svg — 200 — 5.8 KiB — 29 ms — h2https://xdebug.org/images/logos/typo3.svg/images/logos/typo3.svg https://xdebug.org/images/logos/typo3.svg — 200 — 1.9 KiB — 32 ms — h2https://xdebug.org/images/logos/xdebug-cloud.svg/images/logos/xdebug-cloud.svg https://xdebug.org/images/logos/xdebug-cloud.svg — 200 — 7.9 KiB — 35 ms — h2https://xdebug.org/images/logos/seidengroup.svg/images/logos/seidengroup.svg https://xdebug.org/images/logos/seidengroup.svg — 200 — 17.7 KiB — 42 ms — h2https://xdebug.org/images/logos/private-packagist.svg/images/logos/private-packagist.svg https://xdebug.org/images/logos/private-packagist.svg — 200 — 6.0 KiB — 41 ms — h2https://xdebug.org/images/logos/vema.svg/images/logos/vema.svg https://xdebug.org/images/logos/vema.svg — 200 — 1.2 KiB — 51 ms — h2https://xdebug.org/images/logos/weCreate.svg/images/logos/weCreate.svg https://xdebug.org/images/logos/weCreate.svg — 200 — 13.3 KiB — 53 ms — h2https://xdebug.cloud/assets/images/gradient.svgxdebug.cloud/assets/images/gradient... https://xdebug.cloud/assets/images/gradient.svg — 200 — 1.6 KiB — 144 ms — h2https://xdebug.org/fonts/IBMPlexMono-Regular-Latin1.woff2/fonts/IBMPlexMono-Regular-Latin1.w... https://xdebug.org/fonts/IBMPlexMono-Regular-Latin1.woff2 — 200 — 13.3 KiB — 11 ms — h2https://xdebug.org/fonts/IBMPlexSans-SemiBold-Latin1.woff2/fonts/IBMPlexSans-SemiBold-Latin1.... https://xdebug.org/fonts/IBMPlexSans-SemiBold-Latin1.woff2 — 200 — 17.2 KiB — 11 ms — h2https://xdebug.org/fonts/IBMPlexSans-Regular-Latin1.woff2/fonts/IBMPlexSans-Regular-Latin1.w... https://xdebug.org/fonts/IBMPlexSans-Regular-Latin1.woff2 — 200 — 16.3 KiB — 13 ms — h2https://xdebug.org/fonts/IBMPlexSans-MediumItalic-Latin1.woff2/fonts/IBMPlexSans-MediumItalic-Lat... https://xdebug.org/fonts/IBMPlexSans-MediumItalic-Latin1.woff2 — 200 — 18.3 KiB — 12 ms — h2https://xdebug.org/fonts/IBMPlexSans-SemiBoldItalic-Latin1.woff2/fonts/IBMPlexSans-SemiBoldItalic-L... https://xdebug.org/fonts/IBMPlexSans-SemiBoldItalic-Latin1.woff2 — 200 — 17.9 KiB — 13 ms — h2https://xdebug.org/fonts/IBMPlexSans-Medium-Latin1.woff2/fonts/IBMPlexSans-Medium-Latin1.wo... https://xdebug.org/fonts/IBMPlexSans-Medium-Latin1.woff2 — 200 — 16.9 KiB — 14 ms — h2https://xdebug.org/images/favicon.png/images/favicon.png https://xdebug.org/images/favicon.png — 200 — 2.2 KiB — 10 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
40% of JavaScript execution is third-party
First-party Third-party 341ms · 0KB · €4/mo
Unattributable
Other
Costly
Execution 341ms
Transfer 0 KB
Monthly Cost €4/mo

These scripts may cost more than they're worth

  • Unattributable adds 341ms and costs ~€4/month

40% of JavaScript execution time comes from third-party scripts.

Why this matters

Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.

Learn more ▾

Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.

Source: web.dev / HTTP Archive Web Almanac

Unattributable takes 341ms 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

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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