Skip to content
https://yishi99.netlify.app/contact

Performance

· 21 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
89
GRADE
B
FIX
1
REVIEW
6
PASS
12
INFO
2

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

Mobile Desktop
100
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
92
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.

470 ms

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

563 ms

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

1 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.

594 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.

623 ms

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
21
12 PASS 6 REVIEW 1 FIX
F
Page Weight Budget
Action
2.8 MB transferred, 30 requests
FIX
2.8 MB transferred, 30 requests
Warning::
Page weighs 3.3 MB (2.8 MB transferred)
Warning::
Images are 2.7 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 2.7 MB
Info::
30 HTTP requests
Info::
Estimated 0.60 g CO2 per page load
2.8 MB / 2.4 MB budget
2.8 MB transferred
30 requests
0.60 g CO2 per page load
Images 2.7 MiB 94%
JavaScript 141.2 KiB 5%
Other 21.4 KiB 1%
CSS 4.4 KiB 0%
HTML 4.3 KiB 0%
Other 3.3 KiB 0%
0 2.4 MB 4.9 MB
Over budget

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

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.
C
Compression Algorithm
Action
Main response served uncompressed
REVIEW
Main response served uncompressed
Info::
Main HTML response has no Content-Encoding (uncompressed)
The main HTML document is served without compression. The Text Compression section above lists the broader picture; for the main response specifically, even gzip would shave ~70-80% off most text payloads.
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
Page Weight Inventory
Action
30 resources · 2.8 MB · 27 KB savings available
REVIEW
30 resources · 2.8 MB · 27 KB savings available
Warning::
Page weight 2.8 MB exceeds 1 MB target by 1.8 MB
Got: 2.8 MB Expected: ≤ 1 MB
Info::
2 resources over 200KB
30 resources · 2.8 MiB · 0 third-party 1.8 MiB over 1MB target
Image 94% · 2.7 MiB
JavaScript 5% · 141.2 KiB
Document 1% · 17.5 KiB
Other 0% · 11.5 KiB
CSS 0% · 4.4 KiB

~27.5 KiB of savings available

Remove unused JavaScript: 27.5 KiB
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+
Third-Party Impact
No third-party resources
PASS
No third-party resources
Info::
No third-party resources detected
No third-party resources detected — all resources are first-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
2 images, 0 KB saveable
PASS
2 images, 0 KB saveable
Info::
All images are well-optimized
2 images 2.7 MB
0 oversized -0 KB
2 legacy format
0 missing dimensions CLS risk
A+
JS Execution Cost
225ms total JS execution
PASS
225ms total JS execution
Info::
https://yishi99.netlify.app/contact: 80ms CPU time
Info::
https://yishi99.netlify.app/_next/static/chunks/07...: 79ms CPU time
Info::
Unattributable: 66ms CPU time
Info::
Third-party scripts: 66ms (29% of total)

Main Thread Breakdown

Script Evaluation 39% Other 26% Style & Layout 26% Script Parsing & Compilation 8%
ScriptTotalScriptingParse/CompileParty
https://yishi99.netlify.app/contact80ms1ms2ms1st
https://yishi99.netlify.app/_next/static/chunks/07lhk_q6pmm3r.js79ms70ms8ms1st
Unattributable66ms6ms0ms3rd
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+
JS Bundles
7 scripts, 27 KB unused
PASS
7 scripts, 27 KB unused
Warning::
https://yishi99.netlify.app/_next/static/chunks/07...: 27 KB unused (41%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 27 KB
27 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://yishi99.netlify.app/_next/static/chunks/07lhk_q6pmm3r.js67 KB27 KB (41%)✓1st
https://yishi99.netlify.app/_next/static/chunks/0p8tu7idk~nwx.js9 KB—✓1st
https://yishi99.netlify.app/_next/static/chunks/0pqt~8bl3ukh4.js9 KB—✓1st
https://yishi99.netlify.app/_next/static/chunks/0dha171epf-bp.js36 KB—✓1st
https://yishi99.netlify.app/_next/static/chunks/turbopack-01cdivxh8p84x.js4 KB—✓1st
https://yishi99.netlify.app/_next/static/chunks/0m6ou.ufw-o4f.js4 KB—✓1st
https://yishi99.netlify.app/_next/static/chunks/0d3shmwh5_nmn.js12 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

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+
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"; hit
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
Network Waterfall
30 requests over 2838ms
INFO
0 ms 500 ms 1.0 s 1.5 s 2.0 s 2.5 s FCP 470 ms LCP 563 mshttps://yishi99.netlify.app/contact/contact https://yishi99.netlify.app/contact — 200 — 4.3 KiB — 238 ms — h2https://yishi99.netlify.app/_next/static/chunks/184ais~emt2-j.css/_next/static/chunks/184ais~emt2-j.... https://yishi99.netlify.app/_next/static/chunks/184ais~emt2-j.css — 200 — 4.4 KiB — 247 ms — h2https://yishi99.netlify.app/_next/static/chunks/0p8tu7idk~nwx.js/_next/static/chunks/0p8tu7idk~nwx.... https://yishi99.netlify.app/_next/static/chunks/0p8tu7idk~nwx.js — 200 — 8.9 KiB — 235 ms — h2https://yishi99.netlify.app/_next/static/chunks/0pqt~8bl3ukh4.js/_next/static/chunks/0pqt~8bl3ukh4.... https://yishi99.netlify.app/_next/static/chunks/0pqt~8bl3ukh4.js — 200 — 8.7 KiB — 245 ms — h2https://yishi99.netlify.app/_next/static/chunks/07lhk_q6pmm3r.js/_next/static/chunks/07lhk_q6pmm3r.... https://yishi99.netlify.app/_next/static/chunks/07lhk_q6pmm3r.js — 200 — 66.8 KiB — 455 ms — h2https://yishi99.netlify.app/_next/static/chunks/0dha171epf-bp.js/_next/static/chunks/0dha171epf-bp.... https://yishi99.netlify.app/_next/static/chunks/0dha171epf-bp.js — 200 — 36.1 KiB — 255 ms — h2https://yishi99.netlify.app/_next/static/chunks/turbopack-01cdivxh8p84x.js/_next/static/chunks/turbopack-01cd... https://yishi99.netlify.app/_next/static/chunks/turbopack-01cdivxh8p84x.js — 200 — 4.0 KiB — 247 ms — h2https://yishi99.netlify.app/_next/static/chunks/0m6ou.ufw-o4f.js/_next/static/chunks/0m6ou.ufw-o4f.... https://yishi99.netlify.app/_next/static/chunks/0m6ou.ufw-o4f.js — 200 — 4.4 KiB — 235 ms — h2https://yishi99.netlify.app/_next/static/chunks/0d3shmwh5_nmn.js/_next/static/chunks/0d3shmwh5_nmn.... https://yishi99.netlify.app/_next/static/chunks/0d3shmwh5_nmn.js — 200 — 12.1 KiB — 249 ms — h2https://yishi99.netlify.app/favicon.ico/favicon.ico https://yishi99.netlify.app/favicon.ico — 404 — 3.3 KiB — 485 ms — h2https://yishi99.netlify.app/about/about https://yishi99.netlify.app/about — 200 — 78 B — 456 ms — h2https://yishi99.netlify.app/products/products https://yishi99.netlify.app/products — 200 — 76 B — 268 ms — h2https://yishi99.netlify.app// https://yishi99.netlify.app/ — 200 — 77 B — 431 ms — h2https://yishi99.netlify.app/contact/__next._head.txt?_rsc=Edh1o4O2g_TGZBR9/contact/__next._head.txt?_rsc=Edh1... https://yishi99.netlify.app/contact/__next._head.txt?_rsc=Edh1o4O2g_TGZBR9 — 200 — 1.1 KiB — 237 ms — h2https://yishi99.netlify.app/contact/__next._index.txt?_rsc=60m9ttaXtJHZmEpN/contact/__next._index.txt?_rsc=60m... https://yishi99.netlify.app/contact/__next._index.txt?_rsc=60m9ttaXtJHZmEpN — 200 — 1.6 KiB — 247 ms — h2https://yishi99.netlify.app/contact/__next.contact.txt?_rsc=6VCZN-x5fJj_JUAf/contact/__next.contact.txt?_rsc=6V... https://yishi99.netlify.app/contact/__next.contact.txt?_rsc=6VCZN-x5fJj_JUAf — 200 — 532 B — 212 ms — h2https://yishi99.netlify.app/products/__next._tree.txt?_rsc=h2vb-LAkAGynSY5z/products/__next._tree.txt?_rsc=h2v... https://yishi99.netlify.app/products/__next._tree.txt?_rsc=h2vb-LAkAGynSY5z — 200 — 479 B — 208 ms — h2https://yishi99.netlify.app/__next._tree.txt?_rsc=h2vb-LAkAGynSY5z/__next._tree.txt?_rsc=h2vb-LAkAGyn... https://yishi99.netlify.app/__next._tree.txt?_rsc=h2vb-LAkAGynSY5z — 200 — 406 B — 232 ms — h2https://yishi99.netlify.app/about/__next._tree.txt?_rsc=h2vb-LAkAGynSY5z/about/__next._tree.txt?_rsc=h2vb-L... https://yishi99.netlify.app/about/__next._tree.txt?_rsc=h2vb-LAkAGynSY5z — 200 — 400 B — 220 ms — h2https://yishi99.netlify.app/contact/__next.contact.__PAGE__.txt?_rsc=4zImfXNx2m2kMkKG/contact/__next.contact.__PAGE__.tx... https://yishi99.netlify.app/contact/__next.contact.__PAGE__.txt?_rsc=4zImfXNx2m2kMkKG — 404 — 3.2 KiB — 427 ms — h2https://yishi99.netlify.app/images/stretch-film.png/images/stretch-film.png https://yishi99.netlify.app/images/stretch-film.png — 200 — 1.4 MiB — 1.5 s — h2https://yishi99.netlify.app/images/flat-bag.png/images/flat-bag.png https://yishi99.netlify.app/images/flat-bag.png — 200 — 1.2 MiB — 1.1 s — h2https://yishi99.netlify.app/products/__next._head.txt?_rsc=Edh1o4O2g_TGZBR9/products/__next._head.txt?_rsc=Edh... https://yishi99.netlify.app/products/__next._head.txt?_rsc=Edh1o4O2g_TGZBR9 — 200 — 1.0 KiB — 222 ms — h2https://yishi99.netlify.app/products/__next.products.txt?_rsc=Ny0qwzf_nk_S-KoT/products/__next.products.txt?_rsc=... https://yishi99.netlify.app/products/__next.products.txt?_rsc=Ny0qwzf_nk_S-KoT — 200 — 539 B — 213 ms — h2https://yishi99.netlify.app/about/__next._head.txt?_rsc=Edh1o4O2g_TGZBR9/about/__next._head.txt?_rsc=Edh1o4... https://yishi99.netlify.app/about/__next._head.txt?_rsc=Edh1o4O2g_TGZBR9 — 200 — 1.0 KiB — 218 ms — h2https://yishi99.netlify.app/about/__next.about.txt?_rsc=heVSRxVNBbyDJur-/about/__next.about.txt?_rsc=heVSRx... https://yishi99.netlify.app/about/__next.about.txt?_rsc=heVSRxVNBbyDJur- — 200 — 497 B — 219 ms — h2https://yishi99.netlify.app/about/__next.about.__PAGE__.txt?_rsc=0T0S9nhGoUl01ndo/about/__next.about.__PAGE__.txt?_r... https://yishi99.netlify.app/about/__next.about.__PAGE__.txt?_rsc=0T0S9nhGoUl01ndo — 404 — 3.2 KiB — 223 ms — h2https://yishi99.netlify.app/products/__next.products.__PAGE__.txt?_rsc=n3F-kjy8HB6ByxRj/products/__next.products.__PAGE__.... https://yishi99.netlify.app/products/__next.products.__PAGE__.txt?_rsc=n3F-kjy8HB6ByxRj — 404 — 3.2 KiB — 222 ms — h2https://yishi99.netlify.app/__next._head.txt?_rsc=Edh1o4O2g_TGZBR9/__next._head.txt?_rsc=Edh1o4O2g_TG... https://yishi99.netlify.app/__next._head.txt?_rsc=Edh1o4O2g_TGZBR9 — 200 — 1.0 KiB — 218 ms — h2https://yishi99.netlify.app/__next.__PAGE__.txt?_rsc=00jsNgvC9sZ9uZS6/__next.__PAGE__.txt?_rsc=00jsNgvC9... https://yishi99.netlify.app/__next.__PAGE__.txt?_rsc=00jsNgvC9sZ9uZS6 — 200 — 3.1 KiB — 230 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
29% of JavaScript execution is third-party
First-party Third-party 66ms · 0KB · $1/mo
Unattributable
Other
Optional
Execution 66ms
Transfer 0 KB
Monthly Cost $1/mo

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.

Send Feedback