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Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
80
GRADE
B
FIX
0
REVIEW
5
PASS
7
INFO
2

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

Mobile Desktop
96
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
85
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.
75
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.

331 ms

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

1.38 s

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

73 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.

866 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.

1.78 s

Page Load Progression

451 ms
902 ms
1.4 s
1.8 s
2.3 s
2.7 s
3.2 s
3.6 s
Checks
14
7 PASS 5 REVIEW
C
Page Weight Budget
Action
1.7 MB transferred, 70 requests
REVIEW
1.7 MB transferred, 70 requests
Info::
Page weighs 2.7 MB (1.7 MB transferred)
Warning::
Images are 1.0 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 1.0 MB
Info::
70 HTTP requests
Info::
Estimated 0.35 g CO2 per page load
1.7 MB / 2.4 MB budget
1.7 MB transferred
70 requests
0.35 g CO2 per page load
Images 1.0 MiB 62%
JavaScript 484.6 KiB 28%
Other 134.3 KiB 8%
CSS 27.8 KiB 2%
HTML 8.5 KiB 0%
Other 567 B 0%
Other 543 B 0%
0 2.4 MB 4.9 MB
Approaching limit

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

C
Image Optimization
Action
22 images, 0 KB saveable
REVIEW
22 images, 0 KB saveable
Warning::
https://jestjs.io/img/logos/instagram.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://jestjs.io/img/logos/facebook.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://jestjs.io/img/content/feature-fast.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://jestjs.io/img/content/feature-mocking.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://jestjs.io/img/logos/nyt.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://jestjs.io/img/logos/airbnb.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://jestjs.io/img/openjs_foundation-logo-horiz... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://jestjs.io/img/content/feature-coverage.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://jestjs.io/img/logos/twitter.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://jestjs.io/img/logos/spotify.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://jestjs.io/img/content/matchers/toBe.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
22 images 1.0 MB
0 oversized -0 KB
16 legacy format
11 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

C
JS Execution Cost
Action
1355ms total JS execution
REVIEW
1355ms total JS execution
Warning::
https://jestjs.io/: 549ms CPU time
Warning::
https://jestjs.io/assets/js/main.17432a57.js: 481ms CPU time
Info::
Unattributable: 174ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=UA-443...: 76ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-9V0L...: 75ms CPU time
Info::
Third-party scripts: 325ms (24% of total)

Main Thread Breakdown

Script Evaluation 42% Other 21% Style & Layout 19% Rendering 12% Script Parsing & Compilation 5%
ScriptTotalScriptingParse/CompileParty
https://jestjs.io/549ms11ms1ms1st
https://jestjs.io/assets/js/main.17432a57.js481ms392ms24ms1st
Unattributable174ms28ms0ms3rd
https://www.googletagmanager.com/gtag/js?id=UA-44373548-1776ms61ms14ms3rd
https://www.googletagmanager.com/gtag/js?id=G-9V0LCYENMT&cx=c&gtm=4e641175ms56ms19ms3rd
C
JS Bundles
Action
41 scripts, 160 KB unused
REVIEW
41 scripts, 160 KB unused
Warning::
https://www.googletagmanager.com/gtag/js?id=G-9V0L...: 63 KB unused (44%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=UA-443...: 63 KB unused (51%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://jestjs.io/assets/js/main.17432a57.js: 35 KB unused (25%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 160 KB
160 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtag/js?id=G-9V0LCYENMT&cx=c&gtm=4e6411144 KB63 KB (44%)✓3rd
https://www.googletagmanager.com/gtag/js?id=UA-44373548-17124 KB63 KB (51%)✓3rd
https://jestjs.io/assets/js/main.17432a57.js141 KB35 KB (25%)✓1st
https://jestjs.io/assets/js/b2965b2f.8fea91ac.js7 KB—✓1st
https://jestjs.io/assets/js/7a5a5ac2.73be47d0.js10 KB—✓1st
https://jestjs.io/assets/js/1646.9c736360.js7 KB—✓1st
https://jestjs.io/assets/js/c4f5d8e4.f64f7276.js6 KB—✓1st
https://jestjs.io/assets/js/a7456010.2a75c070.js0 KB—✓1st
https://jestjs.io/assets/js/3048.004dfdb5.js2 KB—✓1st
https://www.google-analytics.com/analytics.js21 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

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

B
HTTP Caching
public,max-age=0,must-revalidate
REVIEW
public,max-age=0,must-revalidate
Info::
Cache-Control header is set
Got: public,max-age=0,must-revalidate
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

public,max-age=0,must-revalidate

DirectiveValueMeaning
public—Any cache may store this response
max-age0Cache for 0 seconds
must-revalidate—Must recheck with server after expiry
A+
Third-Party Impact
19% third-party, 0 ms blocking
PASS
19% third-party, 0 ms blocking
Info::
Third-party code accounts for 19% of page weight (325.3 KiB of 1.7 MiB)
Info::
Third-party blocking time is low (0 ms)
81%
19%
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
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+
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
70 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
24% of JavaScript execution is third-party
First-party Third-party 325ms · 268KB · $4/mo
Unattributable
Other
Optional
Execution 174ms
Transfer 0 KB
Monthly Cost $2/mo
Google Tag Manager
Tag Manager
Optional
Execution 76ms
Transfer 124 KB
Unused 51%
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 75ms
Transfer 144 KB
Unused 44%
Monthly Cost $1/mo

51% of Google Tag Manager'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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