Performance

· 23 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.

SCORE

GRADE

A+

FIX

REVIEW

PASS

INFO

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

Mobile Desktop

100

Performance

100

Accessibility

100

Best Practices

100

SEO

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

553 ms

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

673 ms

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.

0.000

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

553 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.

678 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

16 PASS 3 REVIEW

Image Optimization

22 images, 0 KB saveable

REVIEW

22 images, 0 KB saveable

All images are well-optimized

22 images 877 KB

0 oversized -0 KB

4 legacy format

0 missing dimensions CLS risk

Server-Timing Observability

No Server-Timing header found

REVIEW

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.

HTTP Caching

public, max-age=0, must-revalidate

REVIEW

public, max-age=0, must-revalidate

Cache-Control header is set

Got: public, max-age=0, must-revalidate

ETag present — enables conditional (304) responses

Cache-Control

public, max-age=0, must-revalidate

Directive	Value	Meaning
public	—	Any cache may store this response
max-age	0	Cache for 0 seconds
must-revalidate	—	Must recheck with server after expiry

Page Weight Budget

899 KB transferred, 27 requests

PASS

899 KB transferred, 27 requests

Page weighs 927 KB (899 KB transferred)

27 HTTP requests

Estimated 0.18 g CO2 per page load

899 KB transferred

27 requests

0.18 g CO2 per page load

Images 877.4 KiB 98%

HTML 10.0 KiB 1%

CSS 5.3 KiB 1%

JavaScript 5.1 KiB 1%

Other 873 B 0%

0 2.4 MB 4.9 MB

Under budget

Third-Party Impact

38% third-party, 0 ms blocking

PASS

38% third-party, 0 ms blocking

Third-party code accounts for 38% of page weight (343.0 KiB of 898.6 KiB)

Third-party blocking time is low (0 ms)

62%

38%

First-party Third-party

A+

Text Compression

All text resources are compressed

PASS

All text resources are compressed

All text resources are properly compressed.

A+

JS Execution Cost

160ms total JS execution

PASS

160ms total JS execution

https://merging.games/: 107ms CPU time

Unattributable: 53ms CPU time

Main Thread Breakdown

Other 45% Style & Layout 30% Rendering 15% Script Evaluation 8%

Script	Total	Scripting	Parse/Compile	Party
https://merging.games/	107ms	11ms	0ms	1st
Unattributable	53ms	1ms	0ms	1st

A+

Font Loading

No web fonts (system fonts)

PASS

No web fonts (system fonts)

No web fonts loaded — system fonts are fastest

No web fonts loaded — system fonts are optimal.

A+

JS Bundles

2 scripts, 0 KB unused

PASS

2 scripts, 0 KB unused

0 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://merging.games/app.js	3 KB	—	✓	1st
https://merging.games/ga4.js	2 KB	—	✓	1st

A+

Resource Caching

All resources properly cached

PASS

All resources properly cached

No caching issues found

All static resources have appropriate caching headers.

A+

Critical Rendering Path

No render-blocking resources

PASS

No render-blocking resources

No render-blocking resources detected

A+

Resource Hints

No optimization needed

PASS

No optimization needed

No resource hint issues

A+

HTTP/3 (QUIC)

HTTP/3 advertised via Alt-Svc

PASS

HTTP/3 advertised via Alt-Svc

HTTP/3 (QUIC) is supported

First-load mobile users on cellular networks see meaningful latency improvements with HTTP/3. The QUIC transport collapses TLS + TCP handshakes into one and recovers faster from packet loss.

A+

Document Compression

Document response uses brotli

PASS

Document response uses brotli

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

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

Got: public, max-age=0, must-revalidate

Server Response Intelligence

2 server-response signal(s) detected

PASS

2 server-response signal(s) detected

Compressed response missing `Vary` header

The page is served with `Content-Encoding: br` but has no `Vary` header. Without `Vary: Accept-Encoding`, intermediary caches (corporate proxies, ISP caches) may serve the compressed variant to clients that didn't send the matching `Accept-Encoding` -- the client sees garbled bytes. Add `Vary: Accept-Encoding` whenever the response is conditionally compressed.

`ETag` present -- conditional GET supported

A+

Page Weight Inventory

27 resources · 899 KB · 0 KB savings available

PASS

27 resources · 899 KB · 0 KB savings available

Within 1MB page-weight target

Got: 899 KB

5 third-party resources (38% of weight)

27 resources · 898.6 KiB · 5 third-party Within 1MB page-weight target

Image 98% · 878.3 KiB

Document 1% · 10.0 KiB

CSS 1% · 5.3 KiB

JavaScript 1% · 5.1 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

27 resources			898.6 KiB

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

Asset Compression

No text asset hosts to measure

INFO

No text asset hosts to measure

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

27 requests over 351ms

INFO

HTML JavaScript CSS Images Fonts XHR/Fetch Other

Real-User Performance (CrUX)

Field metrics from the Chrome User Experience Report

INFO

Chrome User Experience (CrUX)

Real-user metrics from the Chrome UX Report (2026-09-16 — 2026-10-13)

LCP (p75)

703 ms

98% good

INP (p75)

48 ms

98% good

CLS (p75)

0.000

93% good

FCP (p75)

635 ms

TTFB (p75)

329 ms

This origin passes Core Web Vitals assessment

Image Optimization

25 images, 251 KB total, 0 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

251 KB

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.