Performance
· 15 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.
1.43 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
11.90 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
78 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.032
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
6.31 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.
29.07 s
Page Load Progression
FPage Weight BudgetAction57.1 MB transferred, 107 requestsFIX
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.
Source: web.dev
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.
Source: web.dev
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
Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.
CSS bundle is large — purge unused styles (PurgeCSS, Tailwind JIT) to reduce CSS payload.
Source: web.dev
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.
Source: web.dev
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS BundlesAction52 scripts, 12.7 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.aboutamazon.com/_next/static/chunks/7b01e4aa-5fe4461c000f8c3c.js | 466 KB | 446 KB (96%) | ✓ | 3rd |
| https://www.aboutamazon.com/_next/static/chunks/0cb8460a-3f767e4e7a5b4c41.js | 469 KB | 443 KB (95%) | ✓ | 3rd |
| https://www.aboutamazon.com/_next/static/chunks/ddb11654-a5b8f22571a723db.js | 462 KB | 442 KB (96%) | ✓ | 3rd |
| https://www.aboutamazon.com/_next/static/chunks/ea055470-5ef86b6a7d30494a.js | 456 KB | 437 KB (96%) | ✓ | 3rd |
| https://www.aboutamazon.com/_next/static/chunks/782b29a1-042194358cf30b63.js | 454 KB | 411 KB (91%) | ✓ | 3rd |
| https://www.aboutamazon.com/_next/static/chunks/2396a370-1d25d55aada7240a.js | 457 KB | 409 KB (90%) | ✓ | 3rd |
| https://www.aboutamazon.com/_next/static/chunks/674be3f2-ada3bdb16784b373.js | 410 KB | 398 KB (97%) | ✓ | 3rd |
| https://www.aboutamazon.com/_next/static/chunks/0c2bd621-0f1538c1c022260c.js | 398 KB | 391 KB (99%) | ✓ | 3rd |
| https://www.aboutamazon.com/_next/static/chunks/1e82ba45-8db33434b0c4d8a5.js | 396 KB | 390 KB (99%) | ✓ | 3rd |
| https://www.aboutamazon.com/_next/static/chunks/4c5fd163-8e03899283a6ed48.js | 395 KB | 389 KB (99%) | ✓ | 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
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
FPage Weight InventoryAction107 resources · 57.1 MB · 12.7 MB savings availableFIX
~12.7 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 107 resources | 57.1 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction29 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
CJS Execution CostAction1299ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 714ms | 7ms | 0ms | 3rd |
| https://www.aboutamazon.com/_next/static/chunks/1255-df170c1493f64051.js | 195ms | 188ms | 5ms | 3rd |
| https://www.aboutamazon.com/ | 188ms | 2ms | 4ms | 3rd |
| https://www.aboutamazon.com/_next/static/chunks/d101304b-e0b729dc9698f5c7.js | 126ms | 120ms | 6ms | 3rd |
| https://assets.adobedtm.com/057ba335cefc/edb903aead4f/launch-44ec4d431192.min.js | 76ms | 63ms | 9ms | 3rd |
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+Font Loading14 fonts (921 KB)PASS
Web fonts
14
921 KB total
Render-blocking
0
of 14
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
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 ~173 KB and ~346 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall107 requests over 2861msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 714ms | 0 KB | — | $9/mo | Costly |
www.aboutamazon.com www.aboutamazon.com | Other | 195ms | 169 KB | 44% | $3/mo | Optional |
www.aboutamazon.com www.aboutamazon.com | Other | 188ms | 54 KB | — | $2/mo | Optional |
www.aboutamazon.com www.aboutamazon.com | Other | 126ms | 386 KB | 100% | $2/mo | Optional |
assets.adobedtm.com assets.adobedtm.com | Other | 76ms | 105 KB | 37% | $1/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 714ms and costs ~$9/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
Unattributable takes 714ms 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
100% of www.aboutamazon.com'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