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https://kubernetes.io

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
83
GRADE
B
FIX
1
REVIEW
3
PASS
8
INFO
2

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

Mobile Desktop
89
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
87
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.
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.

879 ms

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

2.05 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.

0.006

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

912 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.

2.05 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
8 PASS 3 REVIEW 1 FIX
D
Page Weight Budget
Action
2.1 MB transferred, 38 requests
FIX
2.1 MB transferred, 38 requests
Info::
Page weighs 3.8 MB (2.1 MB transferred)
Warning::
Images are 1.4 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 1.4 MB
Info::
Fonts are 335 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 335 KB
Info::
38 HTTP requests
Info::
Estimated 0.45 g CO2 per page load
2.1 MB / 2.4 MB budget
2.1 MB transferred
38 requests
0.45 g CO2 per page load
Images 1.4 MiB 64%
Fonts 335.0 KiB 15%
JavaScript 334.7 KiB 15%
CSS 84.4 KiB 4%
Other 26.3 KiB 1%
HTML 11.9 KiB 1%
Other 765 B 0%
Other 568 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

Subset fonts to include only used characters, or switch to system font stacks.

Why this matters

Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).

Source: web.dev font loading

C
Image Optimization
Action
12 images, 0 KB saveable
REVIEW
12 images, 0 KB saveable
Warning::
https://kubernetes.io/_common-resources/images/blo... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://kubernetes.io/case-studies/babylon/babylon... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://kubernetes.io/case-studies/booz-allen/booz... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://kubernetes.io/images/cncf-logo-white.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://kubernetes.io/_common-resources/images/sui... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://kubernetes.io/case-studies/booking-com/boo... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://kubernetes.io/case-studies/appdirect/appdi... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://kubernetes.io/_common-resources/images/flo... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://kubernetes.io/_common-resources/images/sca... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
12 images 1.4 MB
0 oversized -0 KB
12 legacy format
9 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

B
JS Bundles
9 scripts, 134 KB unused
REVIEW
9 scripts, 134 KB unused
Warning::
https://www.googletagmanager.com/gtag/js?id=G-JPP6...: 67 KB unused (40%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.google.com/cse/static/element/b33cba58...: 67 KB unused (68%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 134 KB
134 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtag/js?id=G-JPP6RFM2BP171 KB67 KB (40%)✓3rd
https://www.google.com/cse/static/element/b33cba5881f68fbf/cse_element__en.js?usqp=CAI%3D99 KB67 KB (68%)✓3rd
https://code.jquery.com/jquery-3.6.0.min.js31 KB—✓3rd
https://kubernetes.io/js/banner-dismiss.min.e086e14c068d5d42dee8ba765b034206dd1f3e6c2bd187ed3b94df4341a0ac50.js1 KB—✓1st
https://kubernetes.io/js/legacy-script.js4 KB—✓1st
https://kubernetes.io/js/main.min.c0bae94f0f5db3aec8fd14f4b794baadc13c9fb1eb2e940e28b311ebc95b8b57.js24 KB—✓1st
https://kubernetes.io/js/split-1.6.0.js2 KB—✓1st
https://kubernetes.io/js/detect-js.min.01b26bef8719aa29fb17d861978451b8fbee4b6d1576627b1e1c94dba3084ecc.js0 KB—✓1st
https://cse.google.com/cse.js?cx=013288817511911618469:elfqqbqldzg4 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

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::
ETag present — enables conditional (304) responses
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
18% third-party, 0 ms blocking
PASS
18% third-party, 0 ms blocking
Info::
Third-party code accounts for 18% of page weight (384.4 KiB of 2.1 MiB)
Info::
Third-party blocking time is low (0 ms)
82%
18%
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+
JS Execution Cost
493ms total JS execution
PASS
493ms total JS execution
Info::
https://kubernetes.io/: 170ms CPU time
Info::
Unattributable: 134ms CPU time
Info::
https://code.jquery.com/jquery-3.6.0.min.js: 101ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-JPP6...: 88ms CPU time
Warning::
Third-party scripts: 323ms (66% of total)

Main Thread Breakdown

Script Evaluation 33% Other 27% Style & Layout 25% Script Parsing & Compilation 7% Parse HTML & CSS 6%
ScriptTotalScriptingParse/CompileParty
https://kubernetes.io/170ms1ms1ms1st
Unattributable134ms10ms0ms3rd
https://code.jquery.com/jquery-3.6.0.min.js101ms80ms3ms3rd
https://www.googletagmanager.com/gtag/js?id=G-JPP6RFM2BP88ms70ms18ms3rd
A+
Font Loading
4 fonts (335 KB)
PASS
4 fonts (335 KB)
Info::
4 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

4

335 KB total

Render-blocking

0

of 4

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 879 ms LCP 2.0 shttps://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2memvYaGs126MiZpBA-UvWbX... https://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2 — 42.0 KiB — 0 ms — font-display: swaphttps://kubernetes.io/webfonts/fa-solid-900.woff2fa-solid-900.woff2 https://kubernetes.io/webfonts/fa-solid-900.woff2 — 154.7 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTUGmu0SC55K5gw.woff2memvYaGs126MiZpBA-UvWbX... https://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTUGmu0SC55K5gw.woff2 — 22.2 KiB — 0 ms — font-display: swaphttps://kubernetes.io/webfonts/fa-brands-400.woff2fa-brands-400.woff2 https://kubernetes.io/webfonts/fa-brands-400.woff2 — 116.1 KiB — 0 ms — font-display: swap
memvYaGs126MiZpBA-UvWbX... woff2 swap
Size 42 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
fa-solid-900.woff2 woff2 swap
Size 155 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
memvYaGs126MiZpBA-UvWbX... woff2 swap
Size 22 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
fa-brands-400.woff2 woff2 swap
Size 116 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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)

Fixing the unchecked items could save ~135 KB and ~270 ms

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: Equinix, Inc.

Network Waterfall
38 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
66% of JavaScript execution is third-party
First-party Third-party 323ms · 201KB · $1/mo
Unattributable
Other
Optional
Execution 134ms
Transfer 0 KB
Monthly Cost $0/mo
code.jquery.com
Other
Optional
Execution 101ms
Transfer 31 KB
Monthly Cost $0/mo
Google Tag Manager
Tag Manager
Optional
Execution 88ms
Transfer 171 KB
Unused 40%
Monthly Cost $0/mo

66% 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

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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