Performance
· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
3.56 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
4.47 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
10 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.156
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
3.56 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.
5.52 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 sDThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction20 images, 0 KB saveableREVIEW
Set explicit width and height to prevent CLS.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
CJS Execution CostAction1268ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.whatsapp.com/ | 707ms | 123ms | 28ms | 3rd |
| Unattributable | 280ms | 9ms | 0ms | 3rd |
| https://static.whatsapp.net/rsrc.php/v4/yD/r/qDXfTrpu0Qv.js | 132ms | 68ms | 41ms | 3rd |
| https://static.whatsapp.net/rsrc.php/v4/ye/r/GoPsVrX3zqn.js | 84ms | 59ms | 21ms | 3rd |
| https://static.whatsapp.net/rsrc.php/v4ibQ14/y9/l/en_US-j/j8u7mnmjrtK.js | 65ms | 59ms | 5ms | 3rd |
BJS Bundles13 scripts, 134 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://static.whatsapp.net/rsrc.php/v4/yD/r/qDXfTrpu0Qv.js | 101 KB | 55 KB (55%) | ✓ | 3rd |
| https://static.whatsapp.net/rsrc.php/v4/ye/r/GoPsVrX3zqn.js | 81 KB | 48 KB (59%) | ✓ | 3rd |
| https://static.whatsapp.net/rsrc.php/v4i7M54/yc/l/en_US-j/J3EtfcjxlpA.js | 40 KB | 31 KB (78%) | ✓ | 3rd |
| https://static.whatsapp.net/rsrc.php/v4/yg/r/f153Nzu4IlZ.js | 0 KB | — | ✓ | 3rd |
| https://static.whatsapp.net/rsrc.php/v4/yt/r/e0qnL2dG90H.js | 1 KB | — | ✓ | 3rd |
| https://static.whatsapp.net/rsrc.php/v4/y9/r/6c3fwKSIUKI.js | 1 KB | — | ✓ | 3rd |
| https://static.whatsapp.net/rsrc.php/v4/yY/r/9CF57n7D_FO.js | 4 KB | — | ✓ | 3rd |
| https://static.whatsapp.net/rsrc.php/v4/yV/r/5Xr5wNsw1i5.js | 1 KB | — | ✓ | 3rd |
| https://static.whatsapp.net/rsrc.php/v4/yq/r/Ifn2UJHfihq.js | 3 KB | — | ✓ | 3rd |
| https://static.whatsapp.net/rsrc.php/v4/yb/r/0591o8rJy79.js | 19 KB | — | ✓ | 3rd |
Consider code splitting or tree shaking to reduce unused code.
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.
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.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
APage Weight Budget882 KB transferred, 41 requestsPASS
Subset fonts to include only used characters, or switch to system font stacks.
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 CompressionAll text resources are compressedPASS
A+Font Loading1 fonts (273 KB)PASS
Web fonts
1
273 KB total
Render-blocking
0
of 1
Dominant font-display
swap
Most common across fonts
Font loading timeline
- 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 CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource Hints21 hints, 0 missing preconnectsPASS
Current Resource Hints
21 resource hints configured
APage Weight Inventory41 resources · 882 KB · 134 KB savings availablePASS
~133.6 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 41 resources | 881.5 KiB | ||||||
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall41 requests over 1957msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.whatsapp.com www.whatsapp.com | Other | 707ms | 47 KB | — | $9/mo | Costly |
Unattributable Unattributable | Other | 280ms | 0 KB | — | $4/mo | Costly |
static.whatsapp.net static.whatsapp.net | Other | 132ms | 101 KB | 55% | $2/mo | Optional |
static.whatsapp.net static.whatsapp.net | Other | 84ms | 81 KB | 59% | $1/mo | Optional |
static.whatsapp.net static.whatsapp.net | Other | 65ms | 13 KB | — | $1/mo | Optional |
These scripts may cost more than they're worth
- www.whatsapp.com adds 707ms and costs ~$9/month
- Unattributable adds 280ms and costs ~$4/month
100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
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
www.whatsapp.com takes 707ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
Unattributable takes 280ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
55% of static.whatsapp.net's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
59% of static.whatsapp.net's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev