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Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
91
GRADE
A
FIX
1
REVIEW
3
PASS
11
INFO
2

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

Mobile Desktop
95
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
92
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.
85
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.

1.66 s

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

2.76 s

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

94 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.

1.66 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.

3.57 s

Page Load Progression

406 ms
813 ms
1.2 s
1.6 s
2.0 s
2.4 s
2.8 s
3.3 s
Checks
17
11 PASS 3 REVIEW 1 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 (176.8 KiB of 177.2 KiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
B
Image Optimization
4 images, 0 KB saveable
REVIEW
4 images, 0 KB saveable
Info::
All images are well-optimized
4 images 28 KB
0 oversized -0 KB
4 legacy format
0 missing dimensions CLS risk
B
JS Bundles
2 scripts, 63 KB unused
REVIEW
2 scripts, 63 KB unused
Warning::
https://www.googletagmanager.com/gtag/js?id=G-PXE9...: 63 KB unused (44%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 63 KB
63 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtag/js?id=G-PXE98NKGY2142 KB63 KB (44%)✓3rd
https://cdn.perl.org/js/script.js2 KB—✓3rd

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

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

Green Hosting

No green hosting detected

A+
Page Weight Budget
177 KB transferred, 12 requests
PASS
177 KB transferred, 12 requests
Info::
Page weighs 454 KB (177 KB transferred)
Info::
12 HTTP requests
Info::
Estimated 0.04 g CO2 per page load
177 KB / 2.4 MB budget
177 KB transferred
12 requests
0.04 g CO2 per page load
JavaScript 143.5 KiB 81%
Images 27.5 KiB 16%
HTML 3.1 KiB 2%
CSS 1.3 KiB 1%
Other 897 B 0%
Other 877 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
495ms total JS execution
PASS
495ms total JS execution
Warning::
https://www.googletagmanager.com/gtag/js?id=G-PXE9...: 253ms CPU time
Info::
Unattributable: 140ms CPU time
Info::
https://www.cpan.org/: 102ms CPU time
Warning::
Third-party scripts: 495ms (100% of total)

Main Thread Breakdown

Script Evaluation 45% Other 29% Style & Layout 12% Script Parsing & Compilation 10%
ScriptTotalScriptingParse/CompileParty
https://www.googletagmanager.com/gtag/js?id=G-PXE98NKGY2253ms201ms50ms3rd
Unattributable140ms7ms0ms3rd
https://www.cpan.org/102ms8ms2ms3rd
A+
Font Loading
No web fonts (system fonts)
PASS
No web fonts (system fonts)
Info::
No web fonts loaded — system fonts are fastest
No web fonts loaded — system fonts are optimal.
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
12 resources · 177 KB · 63 KB savings available
PASS
12 resources · 177 KB · 63 KB savings available
Info::
Within 1MB page-weight target
Got: 177 KB
Info::
~63 KB of savings available
Warning::
11 third-party resources (100% of weight)
12 resources · 177.2 KiB · 11 third-party Within 1MB page-weight target
JavaScript 81% · 143.5 KiB
Image 16% · 27.5 KiB
Document 2% · 3.7 KiB
CSS 1% · 1.3 KiB
Other 1% · 1.2 KiB

~62.5 KiB of savings available

Remove unused JavaScript: 62.5 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
HTTP Caching
max-age=86400 (1 day)
PASS
max-age=86400 (1 day)
Info::
Cache-Control header is set
Got: public,max-age=86400
Info::
Effective TTL: 1 day (max-age=86400)
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

public,max-age=86400

DirectiveValueMeaning
public—Any cache may store this response
max-age86400Cache for 1 day
Effective TTL: 86400 seconds
Network Waterfall
12 requests over 1032ms
INFO
0 ms 500 ms 1.0 s 1.5 s 2.0 s 2.5 s FCP 1.7 s LCP 2.8 shttps://cpan.org// https://cpan.org/ — 301 — 323 B — 11 ms — h2https://www.cpan.org/www.cpan.org/ https://www.cpan.org/ — 200 — 3.1 KiB — 19 ms — h2https://www.cpan.org/misc/css/cpan.csswww.cpan.org/misc/css/cpan.css https://www.cpan.org/misc/css/cpan.css — 200 — 1.3 KiB — 43 ms — h2https://cdn.perl.org/js/script.jscdn.perl.org/js/script.js https://cdn.perl.org/js/script.js — 200 — 1.7 KiB — 27 ms — h2https://www.cpan.org/misc/images/cpan.svgwww.cpan.org/misc/images/cpan.svg https://www.cpan.org/misc/images/cpan.svg — 200 — 10.4 KiB — 40 ms — h2https://www.googletagmanager.com/gtag/js?id=G-PXE98NKGY2www.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=G-PXE98NKGY2 — 200 — 141.8 KiB — 76 ms — h2https://www.cpan.org/misc/images/netactuate.pngwww.cpan.org/misc/images/netactuate... https://www.cpan.org/misc/images/netactuate.png — 200 — 4.2 KiB — 6 ms — h3https://www.cpan.org/misc/images/fastly.pngwww.cpan.org/misc/images/fastly.png https://www.cpan.org/misc/images/fastly.png — 200 — 12.2 KiB — 7 ms — h3https://www.cpan.org/misc/images/bg_gradient.jpgwww.cpan.org/misc/images/bg_gradien... https://www.cpan.org/misc/images/bg_gradient.jpg — 200 — 752 B — 42 ms — h3https://cdn.perl.org/api/eventcdn.perl.org/api/event https://cdn.perl.org/api/event — 202 — 350 B — 914 ms — h3https://www.google-analytics.com/g/collect?v=2&tid=G-PXE98NKGY2&gtm=45je64k0h2v889542031za200zd889542031&_p=1776799560007&gcd=13l3l3l3l1l1&npa=0&dma=0&are=1&cid=1305273878.1776799560&frm=0&pscdl=noapi&rcb=3&sr=412x823&uaa=&uab=64&uafvl=Not-A.Brand%3B24.0.0.0%7CChromium%3B146.0.7680.164&uam=moto%20g%20power%20(2022)&uamb=1&uap=Android&uapv=11.0&uaw=0&ul=en-us&_s=1&tag_exp=0~115616985~115938465~115938468~117266400&sid=1776799560&sct=1&seg=0&dl=https%3A%2F%2Fwww.cpan.org%2F&dt=The%20Comprehensive%20Perl%20Archive%20Network%20-%20www.cpan.org&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=240www.google-analytics.com/g/collect?... https://www.google-analytics.com/g/collect?v=2&tid=G-PXE98NKGY2&gtm=45je64k0h2v889542031za200zd889542031&_p=1776799560007&gcd=13l3l3l3l1l1&npa=0&dma=0&are=1&cid=1305273878.1776799560&frm=0&pscdl=noapi&rcb=3&sr=412x823&uaa=&uab=64&uafvl=Not-A.Brand%3B24.0.0.0%7CChromium%3B146.0.7680.164&uam=moto%20g%20power%20(2022)&uamb=1&uap=Android&uapv=11.0&uaw=0&ul=en-us&_s=1&tag_exp=0~115616985~115938465~115938468~117266400&sid=1776799560&sct=1&seg=0&dl=https%3A%2F%2Fwww.cpan.org%2F&dt=The%20Comprehensive%20Perl%20Archive%20Network%20-%20www.cpan.org&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=240 — 204 — 547 B — 38 ms — h2https://www.cpan.org/favicon.icowww.cpan.org/favicon.ico https://www.cpan.org/favicon.ico — 404 — 554 B — 5 ms — h3
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
100% of JavaScript execution is third-party
First-party Third-party 495ms · 145KB · $7/mo
Google Tag Manager
Tag Manager
Costly
Execution 253ms
Transfer 142 KB
Unused 44%
Monthly Cost $3/mo
Unattributable
Other
Optional
Execution 140ms
Transfer 0 KB
Monthly Cost $2/mo
www.cpan.org
Other
Optional
Execution 102ms
Transfer 3 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • Google Tag Manager adds 253ms and costs ~$3/month

100% 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

Google Tag Manager takes 253ms 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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