Performance

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

SCORE

GRADE

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.

586 ms

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

666 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.

856 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.

666 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

14 PASS 5 REVIEW

Image Optimization

20 images, 0 KB saveable

REVIEW

20 images, 0 KB saveable

All images are well-optimized

20 images 258 KB

0 oversized -0 KB

4 legacy format

0 missing dimensions CLS risk

HTTP/3 (QUIC)

HTTP/3 not advertised

REVIEW

HTTP/3 not advertised

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.

Document Compression

Document response uses gzip; brotli would be ~20% smaller

REVIEW

Document response uses gzip; brotli would be ~20% smaller

Main HTML response uses gzip (brotli would be ~20% smaller)

All current browsers support brotli. Most CDNs (Cloudflare, Fastly, AWS CloudFront, Vercel, Netlify) can switch from gzip to brotli with a single config flag. Origin servers (nginx, Apache) need a brotli module compiled in -- nginx-brotli or Apache mod_brotli.

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.

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

A+

Page Weight Budget

345 KB transferred, 27 requests

PASS

345 KB transferred, 27 requests

Page weighs 599 KB (345 KB transferred)

27 HTTP requests

Estimated 0.07 g CO2 per page load

345 KB transferred

27 requests

0.07 g CO2 per page load

Images 258.2 KiB 75%

CSS 33.9 KiB 10%

Other 32.7 KiB 9%

HTML 9.8 KiB 3%

JavaScript 7.8 KiB 2%

Other 2.7 KiB 1%

0 2.4 MB 4.9 MB

Under budget

A+

Third-Party Impact

No third-party resources

PASS

No third-party resources

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

All text resources are properly compressed.

A+

JS Execution Cost

188ms total JS execution

PASS

188ms total JS execution

https://alltaxbooks.com/: 113ms CPU time

Unattributable: 75ms CPU time

Main Thread Breakdown

Other 49% Style & Layout 29% Rendering 9% Script Evaluation 8% Parse HTML & CSS 4%

Script	Total	Scripting	Parse/Compile	Party
https://alltaxbooks.com/	113ms	6ms	1ms	1st
Unattributable	75ms	2ms	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

1 scripts, 0 KB unused

PASS

1 scripts, 0 KB unused

0 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://alltaxbooks.com/atb-site-20261005r32.min.js?v=20261008r51	8 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+

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=300 (≤ 5min) is appropriate

PASS

Main HTML max-age=300 (≤ 5min) is appropriate

Got: public,max-age=300,must-revalidate

A+

Server Response Intelligence

3 server-response signal(s) detected

PASS

3 server-response signal(s) detected

`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.

`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).

`ETag` present -- conditional GET supported

A+

Page Weight Inventory

27 resources · 345 KB · 0 KB savings available

PASS

27 resources · 345 KB · 0 KB savings available

Within 1MB page-weight target

Got: 345 KB

27 resources · 345.2 KiB · 0 third-party Within 1MB page-weight target

Image 84% · 291.0 KiB

CSS 10% · 33.9 KiB

Document 3% · 9.8 KiB

JavaScript 2% · 7.8 KiB

Other 1% · 2.7 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

27 resources			345.2 KiB

A+

HTTP Caching

max-age=300 (5 minutes)

PASS

max-age=300 (5 minutes)

Cache-Control header is set

Got: public,max-age=300,must-revalidate

Effective TTL: 5 minutes (max-age=300)

ETag present — enables conditional (304) responses

Cache-Control

public,max-age=300,must-revalidate

Directive	Value	Meaning
public	—	Any cache may store this response
max-age	300	Cache for 5 minutes
must-revalidate	—	Must recheck with server after expiry

Effective TTL: 300 seconds

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 1399ms

INFO

HTML JavaScript CSS Images Fonts XHR/Fetch Other

Image Optimization

29 images, 22 KB total, 0 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

22 KB

1 missing lazy loading

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