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https://www.allbirds.eu

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
75
GRADE
C
FIX
3
REVIEW
3
PASS
6
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
84
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
87
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
92
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

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

935 ms

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

2.37 s

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

34 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.

1.72 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.

3.15 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
14
6 PASS 3 REVIEW 3 FIX
F
Page Weight Budget
Action
6.1 MB transferred, 210 requests
FIX
6.1 MB transferred, 210 requests
Critical::
Page weighs 13.5 MB (6.1 MB transferred)
Info::
CSS is 1.0 MB — consider purging unused styles
Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.
Got: 1.0 MB
Warning::
JavaScript is 666 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 666 KB
Warning::
210 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 1.3 g CO2 per page load
6.1 MB / 2.4 MB budget
6.1 MB transferred
210 requests
1.3 g CO2 per page load
Other 2.3 MiB 37%
Other 1.1 MiB 17%
CSS 1.0 MiB 17%
Images 864.0 KiB 14%
JavaScript 666.1 KiB 11%
Fonts 167.2 KiB 3%
HTML 56.3 KiB 1%
Other 45.3 KiB 1%
Other 16.5 KiB 0%
Other 6.5 KiB 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over budget

Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.

Why this matters

CSS bundle is large — purge unused styles (PurgeCSS, Tailwind JIT) to reduce CSS payload.

Source: web.dev

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

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (6.1 MiB of 6.1 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
D
HTTP Caching
Action
no-store (uncacheable)
FIX
no-store (uncacheable)
Info::
Cache-Control: no-store prevents all caching
Intentional for dynamic content, but increases server load for every page view.
Got: private, no-store
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

private, no-store

DirectiveValueMeaning
private—Only browser cache, not CDN/proxy
no-store—Never cache this response
B
Image Optimization
38 images, 0 KB saveable
REVIEW
38 images, 0 KB saveable
Info::
All images are well-optimized
38 images 864 KB
0 oversized -0 KB
15 legacy format
0 missing dimensions CLS risk
C
JS Execution Cost
Action
1505ms total JS execution
REVIEW
1505ms total JS execution
Warning::
https://allbirds.de/: 462ms CPU time
Warning::
Unattributable: 297ms CPU time
Warning::
https://cdn.shopify.com/extensions/019d4e67-3077-7...: 278ms CPU time
Info::
https://cdn.shopify.com/extensions/019cc0b2-ef5a-7...: 227ms CPU time
Info::
https://static.zdassets.com/web_widget/messenger/l...: 118ms CPU time
Warning::
Third-party scripts: 1505ms (100% of total)

Main Thread Breakdown

Script Evaluation 48% Style & Layout 23% Other 21% Script Parsing & Compilation 3%
ScriptTotalScriptingParse/CompileParty
https://allbirds.de/462ms47ms9ms3rd
Unattributable297ms10ms0ms3rd
https://cdn.shopify.com/extensions/019d4e67-3077-745b-9dfd-19b65106019d/judgeme-438/assets/loader.js278ms211ms0ms3rd
https://cdn.shopify.com/extensions/019cc0b2-ef5a-74d0-8731-c3578054ad9c/langify-87/assets/langify-lib.js227ms209ms2ms3rd
https://static.zdassets.com/web_widget/messenger/latest/web-widget-main-cf0e543.js118ms91ms23ms3rd
https://allbirds.de/cdn/shop/t/5/assets/theme.js?v=8604476326010062492177487636070ms21ms0ms3rd
https://allbirds.de/cdn/shop/t/5/assets/swiper-init.js?v=1689262205965963506175066100453ms30ms0ms3rd
C
JS Bundles
Action
99 scripts, 175 KB unused
REVIEW
99 scripts, 175 KB unused
Warning::
https://static.zdassets.com/web_widget/messenger/l...: 120 KB unused (51%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://allbirds.de/cdn/shop/t/5/assets/theme.js?v...: 29 KB unused (75%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://allbirds.de/cdn/wpm/b98d3e97aw95287a42p6e3...: 27 KB unused (47%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 175 KB
175 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://static.zdassets.com/web_widget/messenger/latest/web-widget-main-cf0e543.js237 KB120 KB (51%)✓3rd
https://allbirds.de/cdn/shop/t/5/assets/theme.js?v=8604476326010062492177487636039 KB29 KB (75%)✓3rd
https://allbirds.de/cdn/wpm/b98d3e97aw95287a42p6e310ef5m9f58c5a0m.js58 KB27 KB (47%)✓3rd
https://allbirds.de/cdn/shop/t/5/assets/defer-scripts.js?v=7655036086262398917470447252 KB—✓3rd
https://allbirds.de/cdn/shop/t/5/assets/vendor.min.js?v=16291014979217907156174704472422 KB—✓3rd
https://allbirds.de/checkouts/internal/preloads.js?locale=de-DE3 KB—✓3rd
https://shop.app/checkouts/internal/preloads.js?locale=de-DE&shop_id=752433236381 KB—✓3rd
https://allbirds.de/cdn/shopifycloud/shop-js/modules/v2/loader.init-shop-cart-sync.de.esm.js1 KB—✓3rd
https://allbirds.de/cdn/shopifycloud/storefront/assets/storefront/load_feature-496de5fe.js4 KB—✓3rd
https://allbirds.de/cdn/shopifycloud/storefront/assets/shopify_pay/storefront-65b4c6d7.js?v=2025081223 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

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

A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+
Font Loading
9 fonts (167 KB)
PASS
9 fonts (167 KB)
Info::
9 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

9

167 KB total

Render-blocking

0

of 9

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s 1.5 s 2.0 s FCP 935 ms LCP 2.4 shttps://allbirds.de/cdn/shop/files/self-modern_regular.woff2?v=2965self-modern_regular.woff2 https://allbirds.de/cdn/shop/files/self-modern_regular.woff2?v=2965 — 810 B — 0 ms — font-display: swaphttps://allbirds.de/cdn/shop/files/geograph-medium.woff2?v=11013395772660187589geograph-medium.woff2 https://allbirds.de/cdn/shop/files/geograph-medium.woff2?v=11013395772660187589 — 34.5 KiB — 0 ms — font-display: swaphttps://allbirds.de/cdn/shop/files/geograph-regular.woff2?v=8828477634160922462geograph-regular.woff2 https://allbirds.de/cdn/shop/files/geograph-regular.woff2?v=8828477634160922462 — 33.9 KiB — 0 ms — font-display: swaphttps://allbirds.de/cdn/shop/files/geograph-regular-Bold.woff2?v=2965geograph-regular-Bold.w... https://allbirds.de/cdn/shop/files/geograph-regular-Bold.woff2?v=2965 — 957 B — 0 ms — font-display: swaphttps://allbirds.de/cdn/shop/files/geograph-regular-Bold.woff?v=2965geograph-regular-Bold.woff https://allbirds.de/cdn/shop/files/geograph-regular-Bold.woff?v=2965 — 955 B — 0 ms — font-display: swaphttps://allbirds.de/cdn/shop/files/self-modern_regular.woff?v=575159904413907707self-modern_regular.woff https://allbirds.de/cdn/shop/files/self-modern_regular.woff?v=575159904413907707 — 30.3 KiB — 0 ms — font-display: swapdata:application/font-woff;charset=utf-8;base64, d09GRgABAAAAAAZgABAAAAAADAAAAAAAAAAAAAAAAAAAAAAAAA…font-woff;charset=utf-8... data:application/font-woff;charset=utf-8;base64, d09GRgABAAAAAAZgABAAAAAADAAAAAAAAAAAAAAAAAAAAAAAAA… — 1.6 KiB — 0 ms — font-display: swapdata:application/x-font-woff;charset=utf-8;base64,d09GRgABAAAAAAScAA0AAAAABrAAAAAAAAAAAAAAAAAAAAAAA…x-font-woff;charset=utf... data:application/x-font-woff;charset=utf-8;base64,d09GRgABAAAAAAScAA0AAAAABrAAAAAAAAAAAAAAAAAAAAAAA… — 1.2 KiB — 0 ms — font-display: swaphttps://cdn.shopify.com/shop-assets/static_uploads/shoplift/GTStandard-MRegular.woff2GTStandard-MRegular.woff2 https://cdn.shopify.com/shop-assets/static_uploads/shoplift/GTStandard-MRegular.woff2 — 63.1 KiB — 0 ms — font-display: swap
self-modern_regular.woff2 woff2 swap
Size 1 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
geograph-medium.woff2 woff2 swap
Size 34 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
geograph-regular.woff2 woff2 swap
Size 34 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
geograph-regular-Bold.w... woff2 swap
Size 1 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
geograph-regular-Bold.woff woff swap
Size 1 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
self-modern_regular.woff woff swap
Size 30 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
font-woff;charset=utf-8... woff swap
Size 2 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
x-font-woff;charset=utf... woff swap
Size 1 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
GTStandard-MRegular.woff2 woff2 swap
Size 63 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
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 ~10 KB and ~20 ms

A+
Resource Caching
All resources properly cached
PASS
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
No render-blocking resources detected
A+
Resource Hints
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Network Waterfall
210 requests over 0ms
INFO

Performance analysis not available for this result.

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 1505ms · 353KB · €8/mo
allbirds.de
Other
Costly
Execution 462ms
Transfer 54 KB
Monthly Cost €2/mo
Unattributable
Other
Costly
Execution 297ms
Transfer 0 KB
Monthly Cost €2/mo
cdn.shopify.com
Other
Costly
Execution 278ms
Transfer 4 KB
Monthly Cost €1/mo
cdn.shopify.com
Other
Costly
Execution 227ms
Transfer 18 KB
Monthly Cost €1/mo
Zendesk Widget
Customer Support
Optional
Execution 118ms
Transfer 237 KB
Unused 51%
Monthly Cost €1/mo
allbirds.de
Other
Optional
Execution 70ms
Transfer 39 KB
Unused 75%
Monthly Cost €0/mo
allbirds.de
Other
Optional
Execution 53ms
Transfer 1 KB
Monthly Cost €0/mo

These scripts may cost more than they're worth

  • allbirds.de adds 462ms and costs ~€2/month
  • Unattributable adds 297ms and costs ~€2/month
  • cdn.shopify.com adds 278ms and costs ~€1/month
  • cdn.shopify.com adds 227ms and costs ~€1/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

allbirds.de takes 462ms 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

Unattributable takes 297ms 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

cdn.shopify.com takes 278ms 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

cdn.shopify.com takes 227ms 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 Zendesk Widget'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

75% of allbirds.de'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.

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