Performance

· 17 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

Performance

Accessibility

100

Best Practices

SEO

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

5.99 s

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

5.99 s

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

64 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.

5.99 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.

6.06 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

10 PASS 3 REVIEW 2 FIX

Third-Party Impact

Action

100% third-party, 0 ms blocking

FIX

100% third-party, 0 ms blocking

Third-party code accounts for 100% of page weight (577.1 KiB of 577.3 KiB)

Third-party blocking time is low (0 ms)

100%

First-party Third-party

HTTP Caching

Action

no-store (uncacheable)

FIX

no-store (uncacheable)

Cache-Control: no-store prevents all caching

Intentional for dynamic content, but increases server load for every page view.

Got: no-cache, no-store, max-age=0, must-revalidate

No ETag or Last-Modified header

Conditional requests (304 Not Modified) are not possible without validators.

Cache-Control

no-cache, no-store, max-age=0, must-revalidate

Directive	Value	Meaning
no-cache	—	Cache but always revalidate first
no-store	—	Never cache this response
max-age	0	Cache for 0 seconds
must-revalidate	—	Must recheck with server after expiry

JS Execution Cost

Action

1553ms total JS execution

REVIEW

1553ms total JS execution

https://1c5c1ecf7303.eb59107c.us-west-1.token.awsw...: 996ms CPU time

Unattributable: 303ms CPU time

https://www.amazon.com/: 175ms CPU time

https://images-na.ssl-images-amazon.com/images/G/0...: 79ms CPU time

Third-party scripts: 1553ms (100% of total)

Main Thread Breakdown

Script Evaluation 67% Other 17% Script Parsing & Compilation 10% Style & Layout 4%

Script	Total	Scripting	Parse/Compile	Party
https://1c5c1ecf7303.eb59107c.us-west-1.token.awswaf.com/1c5c1ecf7303/d6a7a58005ec/04c5ab18cd2d/challenge.js	996ms	776ms	146ms	3rd
Unattributable	303ms	137ms	0ms	3rd
https://www.amazon.com/	175ms	74ms	7ms	3rd
https://images-na.ssl-images-amazon.com/images/G/01/AUIClients/ClientSideMetricsAUIJavascript-51171fbdd28e1a7a61e922e8f0272af8bc74d37b.secure.variant-desktop-session-snapshot-keypress.min._V2_.js	79ms	54ms	2ms	3rd

JS Bundles

Action

5 scripts, 280 KB unused

REVIEW

5 scripts, 280 KB unused

https://1c5c1ecf7303.eb59107c.us-west-1.token.awsw...: 280 KB unused (56%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 280 KB

280 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://1c5c1ecf7303.eb59107c.us-west-1.token.awswaf.com/1c5c1ecf7303/d6a7a58005ec/04c5ab18cd2d/challenge.js	501 KB	280 KB (56%)	✓	3rd
https://images-na.ssl-images-amazon.com/images/G/01/csminstrumentation/csm-captcha-instrumentation.min.js	2 KB	—	✓	3rd
https://images-na.ssl-images-amazon.com/images/G/01/csminstrumentation/rd-script-6d68177fa6061598e9509dc4b5bdd08d.js	1 KB	—	✓	3rd
https://images-na.ssl-images-amazon.com/images/G/01/csminstrumentation/ue-base-1c399ad9886cab69575e1e5ee15c61a1._V313498596_.js	4 KB	—	✓	3rd
https://images-na.ssl-images-amazon.com/images/G/01/AUIClients/ClientSideMetricsAUIJavascript-51171fbdd28e1a7a61e922e8f0272af8bc74d37b.secure.variant-desktop-session-snapshot-keypress.min._V2_.js	8 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

Page Weight Inventory

18 resources · 577 KB · 280 KB savings available

REVIEW

18 resources · 577 KB · 280 KB savings available

Within 1MB page-weight target

Got: 577 KB

~280 KB of savings available

17 third-party resources (100% of weight)

1 resources over 200KB

18 resources · 577.3 KiB · 17 third-party Within 1MB page-weight target

JavaScript 89% · 515.6 KiB

Image 6% · 35.4 KiB

CSS 3% · 19.3 KiB

Document 1% · 4.7 KiB

Other 0% · 2.2 KiB

~280.0 KiB of savings available

Remove unused JavaScript: 280.0 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

18 resources			577.3 KiB

A+

Page Weight Budget

577 KB transferred, 18 requests

PASS

577 KB transferred, 18 requests

Page weighs 1.6 MB (577 KB transferred)

JavaScript is 516 KB — consider code splitting or lazy loading

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Got: 516 KB

18 HTTP requests

Estimated 0.12 g CO2 per page load

577 KB transferred

18 requests

0.12 g CO2 per page load

JavaScript 515.6 KiB 89%

CSS 19.3 KiB 3%

Other 18.1 KiB 3%

Images 17.6 KiB 3%

HTML 4.5 KiB 1%

Other 2.0 KiB 0%

Other 178 B 0%

0 2.4 MB 4.9 MB

Under budget

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Why this matters

JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.

Source: web.dev

A+

Text Compression

All text resources are compressed

PASS

All text resources are compressed

All text resources are properly compressed.

Image Optimization

2 images, 0 KB saveable

PASS

2 images, 0 KB saveable

https://fls-na.amazon.com/1/oc-csi/1/OP/requestId=... is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

2 images 18 KB

0 oversized -0 KB

2 legacy format

1 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

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+

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+

Render-Blocking Resources

No render-blocking resources detected

PASS

No render-blocking resources detected

No render-blocking resources detected in <head>

A+

Third-Party Resources

No third-party resources detected

PASS

No third-party resources detected

A+

Green Hosting

Whether the site is served from green-energy infrastructure

PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Google Cloud

Network Waterfall

18 requests over 1882ms

INFO

HTML JavaScript CSS Images Fonts XHR/Fetch Other

Third-Party Script Cost

Per-script blocking time, transfer cost, and cache headers

INFO

100% of JavaScript execution is third-party

First-party Third-party 1553ms · 511KB · $21/mo

Script	Category	Execution	Transfer	Unused	Monthly Cost	Verdict
1c5c1ecf7303.eb59107c.us-west-1.token.awswaf.com 1c5c1ecf7303.eb59107c.us-west-1.token.awswaf.com	Other	996ms	501 KB	56%	$13/mo	Costly
Unattributable Unattributable	Other	303ms	0 KB	—	$4/mo	Costly
www.amazon.com www.amazon.com	Other	175ms	2 KB	—	$2/mo	Optional
images-na.ssl-images-amazon.com images-na.ssl-images-amazon.com	Other	79ms	8 KB	—	$1/mo	Optional

1c5c1ecf7303.eb59107c.us-west-1.token.awswaf.com

Other

Costly

Execution 996ms

Transfer 501 KB

Unused 56%

Monthly Cost $13/mo

Unattributable

Other

Costly

Execution 303ms

Transfer 0 KB

Monthly Cost $4/mo

www.amazon.com

Other

Optional

Execution 175ms

Transfer 2 KB

Monthly Cost $2/mo

images-na.ssl-images-amazon.com

Other

Optional

Execution 79ms

Transfer 8 KB

Monthly Cost $1/mo

These scripts may cost more than they're worth

1c5c1ecf7303.eb59107c.us-west-1.token.awswaf.com adds 996ms and costs ~$13/month
Unattributable adds 303ms and costs ~$4/month

100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.

Why this matters

When third-party JS execution time exceeds your own, performance gains from frontend work are capped by code you don't own.

Learn more ▾

Every millisecond of third-party JS competes with your own for main-thread time. If their share is bigger than yours, optimization on your code base barely moves the needle. Audit, defer, or remove third-parties before further frontend optimization. Use Lighthouse's third-party audit to identify the worst offenders.

Source: web.dev

1c5c1ecf7303.eb59107c.us-west-1.token.awswaf.com takes 996ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

56% of 1c5c1ecf7303.eb59107c.us-west-1.token.awswaf.com's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

Unattributable takes 303ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

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.