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https://john-nguembu.netlify.app

Performance

· 26 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
92
GRADE
A
FIX
1
REVIEW
5
PASS
17
INFO
3

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.
91
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.
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.

4.46 s

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

4.64 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.

0.012

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

4.46 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.

4.66 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
26
17 PASS 5 REVIEW 1 FIX
D
Third-Party Impact
Action
71% third-party, 0 ms blocking
FIX
71% third-party, 0 ms blocking
Warning::
Third-party code accounts for 71% of page weight (338.2 KiB of 476.1 KiB)
Info::
Third-party blocking time is low (0 ms)
29%
71%
First-party Third-party
C
JS Execution Cost
Action
1325ms total JS execution
REVIEW
1325ms total JS execution
Warning::
https://john-nguembu.netlify.app/: 1087ms CPU time
Info::
Unattributable: 238ms CPU time

Main Thread Breakdown

Other 41% Style & Layout 38% Script Evaluation 8% Rendering 7% Parse HTML & CSS 4%
ScriptTotalScriptingParse/CompileParty
https://john-nguembu.netlify.app/1087ms103ms7ms1st
Unattributable238ms6ms0ms1st
B
HTTP/3 (QUIC)
HTTP/3 not advertised
REVIEW
HTTP/3 not advertised
Info::
HTTP/3 (QUIC) is not advertised
HTTP/3 isn't advertised via Alt-Svc and the worker didn't negotiate h3. HTTP/3 reduces handshake latency (1-RTT instead of 2-3 RTTs) and is more resilient on lossy connections. Most modern CDNs (Cloudflare, Fastly, AWS CloudFront, Google Cloud CDN) support HTTP/3 with a single config switch -- consider enabling for mobile-heavy workloads.
B
Server-Timing Observability
No Server-Timing header found
REVIEW
No Server-Timing header found
Info::
No Server-Timing header found
Server-Timing exposes backend timing breakdowns to browser DevTools (e.g., `db: 45ms; render: 120ms; cache: 2ms`). Useful for diagnosing slow pages without backend log access. Most modern frameworks (Next.js, Cloudflare Workers, Fastly) emit it automatically; absence on a managed platform usually means telemetry headers are stripped at the edge.
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

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+
Page Weight Budget
476 KB transferred, 9 requests
PASS
476 KB transferred, 9 requests
Info::
Page weighs 667 KB (476 KB transferred)
Info::
Fonts are 318 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 318 KB
Info::
9 HTTP requests
Info::
Estimated 0.10 g CO2 per page load
476 KB / 2.4 MB budget
476 KB transferred
9 requests
0.10 g CO2 per page load
Fonts 317.8 KiB 67%
Images 111.1 KiB 23%
HTML 26.9 KiB 6%
CSS 20.4 KiB 4%
0 2.4 MB 4.9 MB
Under budget

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

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
2 images, 0 KB saveable
PASS
2 images, 0 KB saveable
Info::
All images are well-optimized
2 images 111 KB
0 oversized -0 KB
1 legacy format
0 missing dimensions CLS risk
A+
Font Loading
4 fonts (318 KB)
PASS
4 fonts (318 KB)
Info::
4 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

4

318 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 1.0 s 2.0 s 3.0 s 4.0 s FCP 4.5 s LCP 4.6 shttps://fonts.gstatic.com/s/jetbrainsmono/v24/tDbv2o-flEEny0FZhsfKu5WU4zr3E_BX0PnT8RD8yKwBNntkaToggR7BYRbKPxDcwgknk-4.woff2tDbv2o-flEEny0FZhsfKu5W... https://fonts.gstatic.com/s/jetbrainsmono/v24/tDbv2o-flEEny0FZhsfKu5WU4zr3E_BX0PnT8RD8yKwBNntkaToggR7BYRbKPxDcwgknk-4.woff2 — 30.6 KiB — 49 ms — font-display: swaphttps://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/webfonts/fa-solid-900.woff2fa-solid-900.woff2 https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/webfonts/fa-solid-900.woff2 — 147.3 KiB — 89 ms — font-display: swaphttps://fonts.gstatic.com/s/syne/v24/8vIH7w4qzmVxm2BL9G78HEY.woff28vIH7w4qzmVxm2BL9G78HEY... https://fonts.gstatic.com/s/syne/v24/8vIH7w4qzmVxm2BL9G78HEY.woff2 — 33.8 KiB — 69 ms — font-display: swaphttps://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/webfonts/fa-brands-400.woff2fa-brands-400.woff2 https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/webfonts/fa-brands-400.woff2 — 106.2 KiB — 95 ms — font-display: swap
tDbv2o-flEEny0FZhsfKu5W... woff2 swap
Size 31 KB
Load time 49 ms
Start 415 ms
Risk FOUT — text flashes from fallback to web font
fa-solid-900.woff2 woff2 swap
Size 147 KB
Load time 89 ms
Start 415 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
8vIH7w4qzmVxm2BL9G78HEY... woff2 swap
Size 34 KB
Load time 69 ms
Start 415 ms
Risk FOUT — text flashes from fallback to web font
fa-brands-400.woff2 woff2 swap
Size 106 KB
Load time 95 ms
Start 415 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 ~127 KB and ~254 ms

A+
JS Bundles
No JavaScript
PASS
No JavaScript
Info::
No JavaScript bundles
No JavaScript files loaded.
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
4 hints, 0 missing preconnects
PASS
4 hints, 0 missing preconnects
Info::
Page uses 4 resource hint(s)

Current Resource Hints

preconnect
3
preload
—
dns-prefetch
1
prefetch
—

4 resource hints configured

A+
Document Compression
Document response uses brotli
PASS
Document response uses brotli
Info::
Main HTML response uses brotli (Content-Encoding: br)
Brotli is the best text-compression algorithm for general use, ~20% smaller than gzip on average (40% on smaller files). Modern browsers all support it.
A+
LCP Image Preload
LCP preload audit not available
PASS
LCP preload audit not available
Info::
LCP image preload audit not available for this scan
A+
Main HTML Cache-Control
Main HTML max-age=0 (≤ 5min) is appropriate
PASS
Main HTML max-age=0 (≤ 5min) is appropriate
Info::
Main HTML max-age=0 (≤ 5min) is appropriate
Got: public,max-age=0,must-revalidate
A+
Server Response Intelligence
3 server-response signal(s) detected
PASS
3 server-response signal(s) detected
Info::
`Cache-Status` header present (RFC 9211): "Netlify Edge"; fwd=miss; fwd-status=200; stored
The page returns a `Cache-Status` header -- the standardized way for CDNs and caches to communicate per-hop cache state to debugging tools. Format: `Cache-Status: cdn-name; hit; ttl=300` (or `; fwd=miss` / `; fwd=stale`). Standard alternative to vendor-specific `X-Cache` patterns each CDN had historically. Cloudflare, Fastly, and Akamai all support emitting it.
Info::
`Vary` header declared: Accept-Encoding
The page declares a `Vary` header, telling downstream caches which request headers the response varies on. Critical for content-negotiated responses (compression, language, cookies, device class).
Info::
`ETag` present -- conditional GET supported
A
Page Weight Inventory
9 resources · 476 KB · 0 KB savings available
PASS
9 resources · 476 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 476 KB
Warning::
7 third-party resources (71% of weight)
9 resources · 476.1 KiB · 7 third-party Within 1MB page-weight target
Font 67% · 317.8 KiB
Image 23% · 111.1 KiB
Document 6% · 26.9 KiB
CSS 4% · 20.4 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+
JavaScript Blocking
No render-blocking JS or document.write usage detected
PASS
No render-blocking JS or document.write usage detected
Info::
No JavaScript blocking issues detected
A+
CSS Performance Depth
No CSS performance depth issues detected
PASS
No CSS performance depth issues detected
Info::
No CSS performance depth issues detected
Asset Compression
No text asset hosts to measure
INFO
No text asset hosts to measure
Info::
No third-party or subdomain host served enough text assets to measure
Asset compression is measured per host, from one HEAD request against a sampled resource. Pages that serve all their JS and CSS from the document's own origin are covered by the document compression check instead.
Network Waterfall
9 requests over 654ms
INFO
0 ms 1.0 s 2.0 s 3.0 s 4.0 s FCP 4.5 s LCP 4.6 shttps://john-nguembu.netlify.app// https://john-nguembu.netlify.app/ — 200 — 26.9 KiB — 299 ms — h2https://fonts.googleapis.com/css2?family=Space+Mono:wght@400;700&family=Syne:wght@400;600;700;800&family=JetBrains+Mono:wght@400;600;700&display=swapfonts.googleapis.com/css2?family=Sp... https://fonts.googleapis.com/css2?family=Space+Mono:wght@400;700&family=Syne:wght@400;600;700;800&family=JetBrains+Mono:wght@400;600;700&display=swap — 200 — 1.4 KiB — 132 ms — h2https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/css/all.min.csscdnjs.cloudflare.com/ajax/libs/font... https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/css/all.min.css — 200 — 19.0 KiB — 102 ms — h3data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='…www.w3.org/2000/svg'%3E%3Cfilter id... data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='… — 200 — 0 B — 0 ms — datahttps://fonts.gstatic.com/s/jetbrainsmono/v24/tDbv2o-flEEny0FZhsfKu5WU4zr3E_BX0PnT8RD8yKwBNntkaToggR7BYRbKPxDcwgknk-4.woff2fonts.gstatic.com/s/jetbrainsmono/v... https://fonts.gstatic.com/s/jetbrainsmono/v24/tDbv2o-flEEny0FZhsfKu5WU4zr3E_BX0PnT8RD8yKwBNntkaToggR7BYRbKPxDcwgknk-4.woff2 — 200 — 30.6 KiB — 49 ms — h3https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/webfonts/fa-solid-900.woff2cdnjs.cloudflare.com/ajax/libs/font... https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/webfonts/fa-solid-900.woff2 — 200 — 147.3 KiB — 89 ms — h3https://fonts.gstatic.com/s/syne/v24/8vIH7w4qzmVxm2BL9G78HEY.woff2fonts.gstatic.com/s/syne/v24/8vIH7w... https://fonts.gstatic.com/s/syne/v24/8vIH7w4qzmVxm2BL9G78HEY.woff2 — 200 — 33.8 KiB — 69 ms — h3https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/webfonts/fa-brands-400.woff2cdnjs.cloudflare.com/ajax/libs/font... https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/webfonts/fa-brands-400.woff2 — 200 — 106.2 KiB — 95 ms — h3https://john-nguembu.netlify.app/me2.jpeg/me2.jpeg https://john-nguembu.netlify.app/me2.jpeg — 200 — 111.1 KiB — 213 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Image Optimization
1 images, 111 KB total, 101 KB wasted
INFO

Image Optimization Audit

Total Images

1

Total Size

111 KB

Oversized

1

Wasted

101 KB

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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