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Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
88
GRADE
B
FIX
1
REVIEW
1
PASS
12
INFO
2

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

Mobile Desktop
74
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
86
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.

1.74 s

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

3.01 s

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

802 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.

1.74 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.

7.67 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
12 PASS 1 REVIEW 1 FIX
D
JS Execution Cost
Action
2333ms total JS execution
FIX
2333ms total JS execution
Warning::
https://prometheus.io/_next/static/chunks/255-0edc...: 439ms CPU time
Warning::
https://prometheus.io/: 408ms CPU time
Warning::
https://prometheus.io/_next/static/chunks/341-0544...: 373ms CPU time
Warning::
https://www.googletagmanager.com/gtag/js?id=G-80ZM...: 328ms CPU time
Warning::
Unattributable: 256ms CPU time
Info::
Third-party scripts: 792ms (34% of total)

Main Thread Breakdown

Script Evaluation 62% Script Parsing & Compilation 12% Other 12% Style & Layout 11%
ScriptTotalScriptingParse/CompileParty
https://prometheus.io/_next/static/chunks/255-0edcbb5b637cbfcb.js439ms406ms21ms1st
https://prometheus.io/408ms28ms20ms1st
https://prometheus.io/_next/static/chunks/341-0544a5ed99d6b02e.js373ms311ms61ms1st
https://www.googletagmanager.com/gtag/js?id=G-80ZM8LGB96328ms269ms56ms3rd
Unattributable256ms36ms0ms3rd
https://prometheus.io/_next/static/chunks/4bd1b696-409494caf8c83275.js171ms152ms18ms1st
https://www.googletagmanager.com/gtag/js?id=UA-58468480-1&cx=c&gtm=4e6460158ms115ms41ms3rd
https://prometheus.io/_next/static/chunks/app/docs/layout-93dabed0bf180654.js92ms65ms26ms1st
https://prometheus.io/_next/static/chunks/app/download/page-96109228bfdc297b.js59ms43ms16ms1st
https://www.google-analytics.com/analytics.js51ms43ms7ms3rd
C
JS Bundles
Action
19 scripts, 213 KB unused
REVIEW
19 scripts, 213 KB unused
Warning::
https://prometheus.io/_next/static/chunks/341-0544...: 87 KB unused (61%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=UA-584...: 65 KB unused (57%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-80ZM...: 62 KB unused (40%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 213 KB
213 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://prometheus.io/_next/static/chunks/341-0544a5ed99d6b02e.js142 KB87 KB (61%)✓1st
https://www.googletagmanager.com/gtag/js?id=UA-58468480-1&cx=c&gtm=4e6460115 KB65 KB (57%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-80ZM8LGB96152 KB62 KB (40%)✓3rd
https://prometheus.io/_next/static/chunks/app/page-f3fe9a5180191228.js3 KB—✓1st
https://prometheus.io/_next/static/chunks/app/layout-a67ecb9d553d80eb.js5 KB—✓1st
https://prometheus.io/_next/static/chunks/main-app-95e62da901c4d719.js1 KB—✓1st
https://prometheus.io/_next/static/chunks/619-f072ac750404f9da.js4 KB—✓1st
https://prometheus.io/_next/static/chunks/728-61b6b69bb6f20ba3.js6 KB—✓1st
https://prometheus.io/_next/static/chunks/webpack-b375e03dd2b40bc6.js2 KB—✓1st
https://prometheus.io/_next/static/chunks/687-55fda7d9c0abd233.js52 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

A
Page Weight Budget
824 KB transferred, 37 requests
PASS
824 KB transferred, 37 requests
Info::
Page weighs 2.9 MB (824 KB transferred)
Warning::
JavaScript is 669 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 669 KB
Info::
37 HTTP requests
Info::
Estimated 0.17 g CO2 per page load
824 KB / 2.4 MB budget
824 KB transferred
37 requests
0.17 g CO2 per page load
JavaScript 669.1 KiB 81%
Fonts 62.1 KiB 8%
Other 37.1 KiB 5%
CSS 32.8 KiB 4%
HTML 15.4 KiB 2%
Images 5.6 KiB 1%
Other 1.1 KiB 0%
Other 480 B 0%
0 2.4 MB 4.9 MB
Under budget

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

A
Third-Party Impact
37% third-party, 0 ms blocking
PASS
37% third-party, 0 ms blocking
Info::
Third-party code accounts for 37% of page weight (301.9 KiB of 823.6 KiB)
Info::
Third-party blocking time is low (0 ms)
63%
37%
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
Image Optimization
3 images, 0 KB saveable
PASS
3 images, 0 KB saveable
Info::
All images are well-optimized
3 images 6 KB
0 oversized -0 KB
3 legacy format
0 missing dimensions CLS risk
A+
Font Loading
2 fonts (62 KB)
PASS
2 fonts (62 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

62 KB total

Render-blocking

0

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 1.0 s 2.0 s 3.0 s FCP 1.7 s LCP 3.0 shttps://prometheus.io/_next/static/media/155cae559bbd1a77-s.p.woff2155cae559bbd1a77-s.p.woff2 https://prometheus.io/_next/static/media/155cae559bbd1a77-s.p.woff2 — 14.2 KiB — 0 ms — font-display: swaphttps://prometheus.io/_next/static/media/e4af272ccee01ff0-s.p.woff2e4af272ccee01ff0-s.p.woff2 https://prometheus.io/_next/static/media/e4af272ccee01ff0-s.p.woff2 — 47.9 KiB — 0 ms — font-display: swap
155cae559bbd1a77-s.p.woff2 woff2 swap
Size 14 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
e4af272ccee01ff0-s.p.woff2 woff2 swap
Size 48 KB
Load time 0 ms
Start 0 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+
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
5 hints, 0 missing preconnects
PASS
5 hints, 0 missing preconnects
Info::
Page uses 5 resource hint(s)

Current Resource Hints

preconnect
—
preload
5
dns-prefetch
—
prefetch
—

5 resource hints configured

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

A
HTTP Caching
max-age=14400 (4 hours)
PASS
max-age=14400 (4 hours)
Info::
Cache-Control header is set
Got: public, max-age=14400, must-revalidate
Info::
Effective TTL: 4 hours (max-age=14400)
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

public, max-age=14400, must-revalidate

DirectiveValueMeaning
public—Any cache may store this response
max-age14400Cache for 4 hours
must-revalidate—Must recheck with server after expiry
Effective TTL: 14400 seconds
Network Waterfall
37 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
34% of JavaScript execution is third-party
First-party Third-party 792ms · 288KB · $11/mo
Google Tag Manager
Tag Manager
Costly
Execution 328ms
Transfer 152 KB
Unused 40%
Monthly Cost $4/mo
Unattributable
Other
Costly
Execution 256ms
Transfer 0 KB
Monthly Cost $3/mo
Google Tag Manager
Tag Manager
Optional
Execution 158ms
Transfer 115 KB
Unused 57%
Monthly Cost $2/mo
Google Analytics
Analytics
Optional
Execution 51ms
Transfer 21 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • Google Tag Manager adds 328ms and costs ~$4/month
  • Unattributable adds 256ms and costs ~$3/month

Google Tag Manager takes 328ms 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

Unattributable takes 256ms 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

57% 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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