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

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.

4.41 s

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

5.07 s

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

8 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.

4.41 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.

5.08 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

9 PASS 4 REVIEW 2 FIX

Third-Party Impact

Action

67% third-party, 0 ms blocking

FIX

67% third-party, 0 ms blocking

Third-party code accounts for 67% of page weight (499.1 KiB of 746.1 KiB)

Third-party blocking time is low (0 ms)

33%

67%

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: private, no-cache, no-store, must-revalidate

No ETag or Last-Modified header

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

Cache-Control

private, no-cache, no-store, must-revalidate

Directive	Value	Meaning
private	—	Only browser cache, not CDN/proxy
no-cache	—	Cache but always revalidate first
no-store	—	Never cache this response
must-revalidate	—	Must recheck with server after expiry

Image Optimization

4 images, 0 KB saveable

REVIEW

4 images, 0 KB saveable

https://static.whatsapp.net/rsrc.php/yY/r/_mMwO8HK... is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

https://static.whatsapp.net/rsrc.php/yM/r/ys-5GPT4... is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

4 images 8 KB

0 oversized -0 KB

4 legacy format

2 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

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

JS Execution Cost

Action

1405ms total JS execution

REVIEW

1405ms total JS execution

https://api.whatsapp.com/: 535ms CPU time

Unattributable: 459ms CPU time

https://static.whatsapp.net/rsrc.php/v4/y6/r/n80KC...: 252ms CPU time

https://static.whatsapp.net/rsrc.php/v4ibQ14/yT/l/...: 109ms CPU time

https://static.whatsapp.net/rsrc.php/v4/yz/r/6_kfQ...: 50ms CPU time

Third-party scripts: 870ms (62% of total)

Main Thread Breakdown

Script Evaluation 33% Other 28% Style & Layout 22% Script Parsing & Compilation 6% Garbage Collection 6% Parse HTML & CSS 4%

Script	Total	Scripting	Parse/Compile	Party
https://api.whatsapp.com/	535ms	119ms	18ms	1st
Unattributable	459ms	14ms	0ms	3rd
https://static.whatsapp.net/rsrc.php/v4/y6/r/n80KC3B7ON5.js	252ms	174ms	43ms	3rd
https://static.whatsapp.net/rsrc.php/v4ibQ14/yT/l/en_US-j/WsphHKb4vs6.js	109ms	101ms	6ms	3rd
https://static.whatsapp.net/rsrc.php/v4/yz/r/6_kfQYonLR-.js	50ms	25ms	6ms	3rd

JS Bundles

12 scripts, 83 KB unused

REVIEW

12 scripts, 83 KB unused

https://static.whatsapp.net/rsrc.php/v4/y6/r/n80KC...: 52 KB unused (51%)

Consider code splitting or tree shaking to reduce unused code.

https://static.whatsapp.net/rsrc.php/v4i7M54/ya/l/...: 31 KB unused (79%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 83 KB

83 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://static.whatsapp.net/rsrc.php/v4/y6/r/n80KC3B7ON5.js	101 KB	52 KB (51%)	✓	3rd
https://static.whatsapp.net/rsrc.php/v4i7M54/ya/l/en_US-j/m8jtobM0BaT.js	40 KB	31 KB (79%)	✓	3rd
https://static.whatsapp.net/rsrc.php/v4/yQ/r/bag6ibmFYGc.js	5 KB	—	✓	3rd
https://static.whatsapp.net/rsrc.php/v4/yl/r/5TReKLCGPcC.js	0 KB	—	✓	3rd
https://static.whatsapp.net/rsrc.php/v4/yR/r/MzhkMBApLms.js	18 KB	—	✓	3rd
https://static.whatsapp.net/rsrc.php/v4/yz/r/6_kfQYonLR-.js	15 KB	—	✓	3rd
https://static.whatsapp.net/rsrc.php/v4/yQ/r/6G9Xg5DVlKP.js	1 KB	—	✓	3rd
https://static.whatsapp.net/rsrc.php/v4ibQ14/yT/l/en_US-j/WsphHKb4vs6.js	13 KB	—	✓	3rd
https://api.whatsapp.com/ajax/bz?__a=1&__ccg=UNKNOWN&__dyn=7xe6E5aQ1PyUbFp41twpUnwgU29zE6u7E3rw5ux609vCwjE1EE2Cw8G0um4o5-0me0sy0ny0RE2Jw8W1uw2oE17U2ZwrU1Xo1UU1JE&__hs=20564.BP%3Awhatsapp_www_pkg.2.0...0&__hsi=7631285575364554455&__req=1&__rev=1037799039&__s=q4irhh%3Asbr0sk%3Ae2pj94&__user=0&dpr=2&jazoest=21772&lsd=NElTBAvrtvT-R958N5xGU4	0 KB	—	✓	1st
https://api.whatsapp.com/ajax/bz?__a=1&__ccg=UNKNOWN&__dyn=7xe6E5aQ1PyUbFp41twpUnwgU29zE6u7E3rw5ux609vCwjE1EE2Cw8G0um4o5-0me0sy0ny0RE2Jw8W1uw2oE17U2ZwrU1Xo1UU1JE&__hs=20564.BP%3Awhatsapp_www_pkg.2.0...0&__hsi=7631285575364554455&__req=2&__rev=1037799039&__s=q4irhh%3Asbr0sk%3Ae2pj94&__user=0&dpr=2&jazoest=21772&lsd=NElTBAvrtvT-R958N5xGU4	0 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

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

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

Page Weight Budget

746 KB transferred, 24 requests

PASS

746 KB transferred, 24 requests

Page weighs 1.8 MB (746 KB transferred)

Fonts are 273 KB — consider subsetting or using system fonts

Subset fonts to include only used characters, or switch to system font stacks.

Got: 273 KB

24 HTTP requests

Estimated 0.15 g CO2 per page load

746 KB transferred

24 requests

0.15 g CO2 per page load

Fonts 272.9 KiB 37%

JavaScript 193.5 KiB 26%

Other 110.7 KiB 15%

Other 94.3 KiB 13%

HTML 42.0 KiB 6%

CSS 24.7 KiB 3%

Images 8.0 KiB 1%

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

All text resources are properly compressed.

A+

Font Loading

1 fonts (273 KB)

PASS

1 fonts (273 KB)

1 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

273 KB total

Render-blocking

of 1

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

fQtw5exLIdT.woff2 woff2 swap

Size 273 KB

Load time 21 ms

Start 370 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 ~136 KB and ~272 ms

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

11 hints, 0 missing preconnects

PASS

11 hints, 0 missing preconnects

Page uses 11 resource hint(s)

Current Resource Hints

preconnect

—

preload

dns-prefetch

—

prefetch

—

11 resource hints configured

Page Weight Inventory

24 resources · 746 KB · 83 KB savings available

PASS

24 resources · 746 KB · 83 KB savings available

Within 1MB page-weight target

Got: 746 KB

~83 KB of savings available

18 third-party resources (67% of weight)

1 resources over 200KB

24 resources · 746.1 KiB · 18 third-party Within 1MB page-weight target

JavaScript 41% · 304.2 KiB

Font 37% · 272.9 KiB

Document 18% · 136.3 KiB

CSS 3% · 24.7 KiB

Image 1% · 8.0 KiB

~82.8 KiB of savings available

Remove unused JavaScript: 82.8 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

24 resources			746.1 KiB

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

Network Waterfall

24 requests over 10422ms

INFO

HTML JavaScript CSS Images Fonts XHR/Fetch Other

Third-Party Script Cost

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

INFO

62% of JavaScript execution is third-party

First-party Third-party 870ms · 129KB · $12/mo

Script	Category	Execution	Transfer	Unused	Monthly Cost	Verdict
Unattributable Unattributable	Other	459ms	0 KB	—	$6/mo	Costly
static.whatsapp.net static.whatsapp.net	Other	252ms	101 KB	51%	$3/mo	Costly
static.whatsapp.net static.whatsapp.net	Other	109ms	13 KB	—	$1/mo	Optional
static.whatsapp.net static.whatsapp.net	Other	50ms	15 KB	—	$1/mo	Optional

Unattributable

Other

Costly

Execution 459ms

Transfer 0 KB

Monthly Cost $6/mo

static.whatsapp.net

Other

Costly

Execution 252ms

Transfer 101 KB

Unused 51%

Monthly Cost $3/mo

static.whatsapp.net

Other

Optional

Execution 109ms

Transfer 13 KB

Monthly Cost $1/mo

static.whatsapp.net

Other

Optional

Execution 50ms

Transfer 15 KB

Monthly Cost $1/mo

These scripts may cost more than they're worth

Unattributable adds 459ms and costs ~$6/month
static.whatsapp.net adds 252ms and costs ~$3/month

62% of JavaScript execution time comes from third-party scripts.

Why this matters

Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.

Learn more ▾

Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.

Source: web.dev / HTTP Archive Web Almanac

Unattributable takes 459ms 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

static.whatsapp.net takes 252ms 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

51% of static.whatsapp.net'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

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.