Performance
· 26 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.
5.41 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
5.86 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
536 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.024
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
5.41 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.
9.25 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
DJS Execution CostAction2686ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 850ms | 280ms | 0ms | 3rd |
| https://asset.zcache.com/bld/z.3/mobile/vendor.d8dc1c8c75f522.js | 478ms | 449ms | 2ms | 3rd |
| https://www.zazzle.com/ | 452ms | 15ms | 22ms | 3rd |
| https://www.zazzle.com/cgtw/X75t_m90HdNuaQI51oK8cqAbrGP79AeZpaCIBu9S4t-9ZnT1eHQujFzU6g | 359ms | 307ms | 47ms | 3rd |
| https://www.zazzle.com/cgtw/?id=GTM-MLV372Q>m_auth=PK96U0sSRa3-sRYTKoYtBQ>m_preview=env-57>m_cookies_win=x | 260ms | 197ms | 42ms | 3rd |
| https://www.zazzle.com/_fs-ch-1T1wmsGaOgGaSxcX/assets/botdefence.js | 235ms | 207ms | 18ms | 3rd |
| https://asset.zcache.com/bld/z.3/mobile/purchase.1f2e31bad4b01b.js | 52ms | 34ms | 2ms | 3rd |
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BPage Weight Budget1.3 MB transferred, 79 requestsREVIEW
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
CJS BundlesAction30 scripts, 293 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.zazzle.com/cgtw/X75t_m90HdNuaQI51oK8cqAbrGP79AeZpaCIBu9S4t-9ZnT1eHQujFzU6g | 182 KB | 73 KB (40%) | ✓ | 3rd |
| https://asset.zcache.com/bld/z.3/mobile/purchase.1f2e31bad4b01b.js | 106 KB | 65 KB (62%) | ✓ | 3rd |
| https://www.zazzle.com/cgtw/?id=GTM-MLV372Q>m_auth=PK96U0sSRa3-sRYTKoYtBQ>m_preview=env-57>m_cookies_win=x | 155 KB | 62 KB (40%) | ✓ | 3rd |
| https://asset.zcache.com/bld/z.3/mobile/vendor.d8dc1c8c75f522.js | 114 KB | 38 KB (39%) | ✓ | 3rd |
| https://www.zazzle.com/_fs-ch-1T1wmsGaOgGaSxcX/assets/botdefence.js | 217 KB | 33 KB (15%) | ✓ | 3rd |
| https://asset.zcache.com/bld/z.3/mobile/header-Header2021.284dd962d83b25.js | 30 KB | 22 KB (72%) | ✓ | 3rd |
| https://asset.zcache.com/bld/z.3/mobile/7.4d037e084d688f.js | 4 KB | — | ✓ | 3rd |
| https://asset.zcache.com/bld/z.3/mobile/CmsCollection.4cde2711ac64c2.js | 1 KB | — | ✓ | 3rd |
| https://asset.zcache.com/bld/z.3/mobile/16.2c4d55dfa54414.js | 3 KB | — | ✓ | 3rd |
| https://asset.zcache.com/bld/z.3/mobile/22.6ef1b32f358bca.js | 17 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
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
BHTTP/3 (QUIC)HTTP/3 not advertisedREVIEW
CCompression AlgorithmActionMain response served uncompressedREVIEW
BMain HTML Cache-ControlNo Cache-Control header on main HTML responseREVIEW
BServer-Timing ObservabilityNo Server-Timing header foundREVIEW
CPage Weight InventoryAction79 resources · 1.3 MB · 293 KB savings availableREVIEW
~292.6 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 79 resources | 1.3 MiB | ||||||
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+Image Optimization12 images, 0 KB saveablePASS
A+Font Loading6 fonts (139 KB)PASS
Web fonts
6
139 KB total
Render-blocking
0
of 6
Dominant font-display
swap
Most common across fonts
Font loading timeline
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)
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
A+LCP Image PreloadLCP preload audit not availablePASS
A+Server Response Intelligence1 server-response signal(s) detectedPASS
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
A+JavaScript BlockingNo render-blocking JS or document.write usage detectedPASS
A+CSS Performance DepthNo CSS performance depth issues detectedPASS
Network Waterfall79 requests over 2178msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 850ms | 0 KB | — | $11/mo | Costly |
asset.zcache.com asset.zcache.com | Other | 478ms | 114 KB | 39% | $6/mo | Costly |
www.zazzle.com www.zazzle.com | Other | 452ms | 55 KB | — | $6/mo | Costly |
www.zazzle.com www.zazzle.com | Other | 359ms | 182 KB | 40% | $5/mo | Costly |
www.zazzle.com www.zazzle.com | Other | 260ms | 155 KB | 40% | $3/mo | Costly |
www.zazzle.com www.zazzle.com | Other | 235ms | 217 KB | 15% | $3/mo | Costly |
asset.zcache.com asset.zcache.com | Other | 52ms | 106 KB | 62% | $1/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 850ms and costs ~$11/month
- asset.zcache.com adds 478ms and costs ~$6/month
- www.zazzle.com adds 452ms and costs ~$6/month
- www.zazzle.com adds 359ms and costs ~$5/month
- www.zazzle.com adds 260ms and costs ~$3/month
- www.zazzle.com adds 235ms and costs ~$3/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 850ms 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
asset.zcache.com takes 478ms 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
www.zazzle.com takes 452ms 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
www.zazzle.com takes 359ms 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
www.zazzle.com takes 260ms 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
www.zazzle.com takes 235ms 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
62% of asset.zcache.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
Image Optimization2 images, 0 KB total, 0 KB wastedINFO
Image Optimization Audit
Total Images
2
Total Size
0 KB
Oversized
2