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Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
85
GRADE
B
FIX
1
REVIEW
4
PASS
7
INFO
2

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

Mobile Desktop
72
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
81
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
92
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
92
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.

1.94 s

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

5.69 s

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

274 ms

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

0.001

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

2.67 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.

5.81 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
14
7 PASS 4 REVIEW 1 FIX
D
JS Execution Cost
Action
2784ms total JS execution
FIX
2784ms total JS execution
Warning::
https://spring.io/: 952ms CPU time
Warning::
https://spring.io/framework-f0de980621661f0b7a47.j...: 608ms CPU time
Warning::
Unattributable: 506ms CPU time
Warning::
https://cdn.cookielaw.org/scripttemplates/202509.1...: 355ms CPU time
Info::
https://www.googletagmanager.com/gtm.js?id=GTM-W8C...: 221ms CPU time
Info::
Third-party scripts: 1143ms (41% of total)

Main Thread Breakdown

Script Evaluation 37% Other 28% Style & Layout 18% Script Parsing & Compilation 7% Parse HTML & CSS 5% Rendering 4%
ScriptTotalScriptingParse/CompileParty
https://spring.io/952ms47ms7ms1st
https://spring.io/framework-f0de980621661f0b7a47.js608ms419ms22ms1st
Unattributable506ms88ms0ms3rd
https://cdn.cookielaw.org/scripttemplates/202509.1.0/otBannerSdk.js355ms219ms73ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-W8CQ8TL221ms165ms54ms3rd
https://spring.io/commons-522737e33bff6863b536.js81ms44ms16ms1st
https://cdn.cookielaw.org/scripttemplates/otSDKStub.js61ms36ms4ms3rd
B
Third-Party Impact
55% third-party, 0 ms blocking
REVIEW
55% third-party, 0 ms blocking
Warning::
Third-party code accounts for 55% of page weight (384.4 KiB of 693.2 KiB)
Info::
Third-party blocking time is low (0 ms)
45%
55%
First-party Third-party
B
Image Optimization
14 images, 0 KB saveable
REVIEW
14 images, 0 KB saveable
Warning::
https://spring.io/img/extra/quote.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
14 images 79 KB
0 oversized -0 KB
14 legacy format
1 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

B
JS Bundles
13 scripts, 138 KB unused
REVIEW
13 scripts, 138 KB unused
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-W8C...: 74 KB unused (56%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cdn.cookielaw.org/scripttemplates/202509.1...: 64 KB unused (53%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 138 KB
138 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtm.js?id=GTM-W8CQ8TL133 KB74 KB (56%)✓3rd
https://cdn.cookielaw.org/scripttemplates/202509.1.0/otBannerSdk.js122 KB64 KB (53%)✓3rd
https://spring.io/app-eb2299719d986c7bfa17.js24 KB—✓1st
https://cdn.cookielaw.org/scripttemplates/otSDKStub.js9 KB—✓3rd
https://static.cloudflareinsights.com/beacon.min.js11 KB—✓3rd
https://static.cloudflareinsights.com/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da177152312451611 KB—✓3rd
https://spring.io/framework-f0de980621661f0b7a47.js45 KB—✓1st
https://spring.io/c16184b3-bf3bd3a4ce2c0f7585be.js3 KB—✓1st
https://spring.io/2cca2479-52cc2fee7444ce8367e9.js2 KB—✓1st
https://spring.io/commons-522737e33bff6863b536.js34 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

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+
Page Weight Budget
693 KB transferred, 51 requests
PASS
693 KB transferred, 51 requests
Info::
Page weighs 2.1 MB (693 KB transferred)
Info::
51 HTTP requests
Info::
Estimated 0.14 g CO2 per page load
693 KB / 2.4 MB budget
693 KB transferred
51 requests
0.14 g CO2 per page load
JavaScript 402.1 KiB 58%
Fonts 95.8 KiB 14%
Images 79.2 KiB 11%
HTML 64.0 KiB 9%
Other 37.8 KiB 5%
Other 7.7 KiB 1%
Other 5.8 KiB 1%
Other 788 B 0%
Other 0 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+
Font Loading
6 fonts (96 KB)
PASS
6 fonts (96 KB)
Info::
6 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

6

96 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 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s FCP 1.9 s LCP 5.7 shttps://spring.io/fonts/open-sans-v17-latin/open-sans-v17-latin-regular.woff2open-sans-v17-latin-reg... https://spring.io/fonts/open-sans-v17-latin/open-sans-v17-latin-regular.woff2 — 14.3 KiB — 0 ms — font-display: swaphttps://spring.io/fonts/metropolis/metropolis-bold-webfont.woff2metropolis-bold-webfont... https://spring.io/fonts/metropolis/metropolis-bold-webfont.woff2 — 14.8 KiB — 0 ms — font-display: swaphttps://spring.io/fonts/open-sans-v17-latin/open-sans-v17-latin-700.woff2open-sans-v17-latin-700... https://spring.io/fonts/open-sans-v17-latin/open-sans-v17-latin-700.woff2 — 15.0 KiB — 0 ms — font-display: swaphttps://spring.io/fonts/metropolis/metropolis-extrabold-webfont.woff2metropolis-extrabold-we... https://spring.io/fonts/metropolis/metropolis-extrabold-webfont.woff2 — 14.7 KiB — 0 ms — font-display: swaphttps://spring.io/fonts/work-sans-v5-latin/work-sans-v5-latin-regular.woff2work-sans-v5-latin-regu... https://spring.io/fonts/work-sans-v5-latin/work-sans-v5-latin-regular.woff2 — 22.2 KiB — 0 ms — font-display: swaphttps://spring.io/fonts/open-sans-v17-latin/open-sans-v17-latin-600.woff2open-sans-v17-latin-600... https://spring.io/fonts/open-sans-v17-latin/open-sans-v17-latin-600.woff2 — 14.8 KiB — 0 ms — font-display: swap
open-sans-v17-latin-reg... woff2 swap
Size 14 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
metropolis-bold-webfont... woff2 swap
Size 15 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
open-sans-v17-latin-700... woff2 swap
Size 15 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
metropolis-extrabold-we... woff2 swap
Size 15 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
work-sans-v5-latin-regu... woff2 swap
Size 22 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
open-sans-v17-latin-600... woff2 swap
Size 15 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
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
51 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
41% of JavaScript execution is third-party
First-party Third-party 1143ms · 264KB · $4/mo
Unattributable
Other
Costly
Execution 506ms
Transfer 0 KB
Monthly Cost $2/mo
OneTrust
Consent
Essential
Execution 355ms
Transfer 122 KB
Unused 53%
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Costly
Execution 221ms
Transfer 133 KB
Unused 56%
Monthly Cost $1/mo
OneTrust
Consent
Essential
Execution 61ms
Transfer 9 KB
Monthly Cost $0/mo

These scripts may cost more than they're worth

  • Unattributable adds 506ms and costs ~$2/month
  • Google Tag Manager adds 221ms and costs ~$1/month

41% 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 506ms 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

53% of OneTrust'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 221ms 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

56% 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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