Skip to content
https://www.allbirds.eu

Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
75
GRADE
C
FIX
4
REVIEW
2
PASS
8
INFO
2

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

Mobile Desktop
33
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.

5.69 s

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

20.06 s

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

1.36 s

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.

7.93 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.

20.39 s

Page Load Progression

395 ms
790 ms
1.2 s
1.6 s
2.0 s
2.4 s
2.8 s
3.2 s
Checks
16
8 PASS 2 REVIEW 4 FIX
F
Page Weight Budget
Action
5.6 MB transferred, 197 requests
FIX
5.6 MB transferred, 197 requests
Critical::
Page weighs 13.3 MB (5.6 MB transferred)
Warning::
Images are 1.6 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 1.6 MB
Info::
CSS is 1007 KB — consider purging unused styles
Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.
Got: 1007 KB
Warning::
JavaScript is 664 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 664 KB
Warning::
197 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 1.2 g CO2 per page load
5.6 MB / 2.4 MB budget
5.6 MB transferred
197 requests
1.2 g CO2 per page load
Images 1.6 MiB 28%
Other 1.1 MiB 20%
Other 1.0 MiB 18%
CSS 1006.7 KiB 18%
JavaScript 664.3 KiB 12%
Fonts 167.5 KiB 3%
HTML 56.4 KiB 1%
Other 45.7 KiB 1%
Other 16.6 KiB 0%
Other 6.4 KiB 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over budget

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Why this matters

Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.

Source: web.dev

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 (5.6 MiB of 5.6 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Execution Cost
Action
6087ms total JS execution
FIX
6087ms total JS execution
Warning::
https://cdn.shopify.com/extensions/019d4e67-3077-7...: 1373ms CPU time
Warning::
https://allbirds.de/: 1040ms CPU time
Warning::
Unattributable: 967ms CPU time
Warning::
https://static.zdassets.com/web_widget/messenger/l...: 651ms CPU time
Warning::
https://cdn.shopify.com/extensions/019cc0b2-ef5a-7...: 458ms CPU time
Warning::
Third-party scripts: 6087ms (100% of total)

Main Thread Breakdown

Script Evaluation 51% Style & Layout 22% Other 20% Script Parsing & Compilation 4%
ScriptTotalScriptingParse/CompileParty
https://cdn.shopify.com/extensions/019d4e67-3077-745b-9dfd-19b65106019d/judgeme-438/assets/loader.js1373ms1153ms1ms3rd
https://allbirds.de/1040ms93ms26ms3rd
Unattributable967ms28ms0ms3rd
https://static.zdassets.com/web_widget/messenger/latest/web-widget-main-cf0e543.js651ms460ms101ms3rd
https://cdn.shopify.com/extensions/019cc0b2-ef5a-74d0-8731-c3578054ad9c/langify-87/assets/langify-lib.js458ms405ms7ms3rd
https://allbirds.de/cdn/shop/t/5/assets/theme.js?v=86044763260100624921774876360333ms79ms1ms3rd
https://allbirds.de/cdn/shop/t/5/assets/swiper-init.js?v=16892622059659635061750661004283ms132ms0ms3rd
https://static.zdassets.com/web_widget/messenger/latest/web-widget-4439-cf0e543.js233ms135ms4ms3rd
https://allbirds.de/cdn/wpm/b98d3e97aw95287a42p6e310ef5m9f58c5a0m.js182ms95ms15ms3rd
https://static.zdassets.com/web_widget/messenger/latest/web-widget-locales/messenger/en-us-json-cf0e543.js113ms94ms4ms3rd

Showing top 10 of 16 scripts

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
35 images, 0 KB saveable
REVIEW
35 images, 0 KB saveable
Info::
All images are well-optimized
35 images 1.6 MB
0 oversized -0 KB
12 legacy format
0 missing dimensions CLS risk
C
JS Bundles
Action
99 scripts, 203 KB unused
REVIEW
99 scripts, 203 KB unused
Warning::
https://static.zdassets.com/web_widget/messenger/l...: 119 KB unused (50%)
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://cdn.jsdelivr.net/npm/swiper@11/swiper-bund...: 28 KB unused (65%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://allbirds.de/cdn/wpm/b98d3e97aw95287a42p6e3...: 27 KB unused (46%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 203 KB
203 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://static.zdassets.com/web_widget/messenger/latest/web-widget-main-cf0e543.js237 KB119 KB (50%)✓3rd
https://allbirds.de/cdn/shop/t/5/assets/theme.js?v=8604476326010062492177487636039 KB29 KB (75%)✓3rd
https://cdn.jsdelivr.net/npm/swiper@11/swiper-bundle.min.js43 KB28 KB (65%)✓3rd
https://allbirds.de/cdn/wpm/b98d3e97aw95287a42p6e310ef5m9f58c5a0m.js58 KB27 KB (46%)✓3rd
https://allbirds.de/cdn/shop/t/5/assets/defer-scripts.js?v=7655036086262398917470447250 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

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

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 (168 KB)
PASS
9 fonts (168 KB)
Info::
9 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

9

168 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 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s 12.0 s 14.0 s 16.0 s 18.0 s 20.0 s FCP 5.7 s LCP 20.1 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 — 782 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 — 34.2 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 — 958 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 — 950 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: 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 — 63.2 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: 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
GTStandard-MRegular.woff2 woff2 swap
Size 63 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
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
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
22 hints, 0 missing preconnects
PASS
22 hints, 0 missing preconnects
Info::
Page uses 22 resource hint(s)

Current Resource Hints

preconnect
5
preload
4
dns-prefetch
6
prefetch
7

22 resource hints configured

A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
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
197 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 6087ms · 581KB · €32/mo
cdn.shopify.com
Other
Costly
Execution 1373ms
Transfer 4 KB
Monthly Cost €7/mo
allbirds.de
Other
Costly
Execution 1040ms
Transfer 54 KB
Monthly Cost €6/mo
Unattributable
Other
Costly
Execution 967ms
Transfer 0 KB
Monthly Cost €5/mo
Zendesk Widget
Customer Support
Costly
Execution 651ms
Transfer 237 KB
Unused 50%
Monthly Cost €3/mo
cdn.shopify.com
Other
Costly
Execution 458ms
Transfer 18 KB
Monthly Cost €2/mo
allbirds.de
Other
Costly
Execution 333ms
Transfer 39 KB
Unused 75%
Monthly Cost €2/mo
allbirds.de
Other
Costly
Execution 283ms
Transfer 1 KB
Monthly Cost €2/mo
Zendesk Widget
Customer Support
Costly
Execution 233ms
Transfer 14 KB
Monthly Cost €1/mo
allbirds.de
Other
Optional
Execution 182ms
Transfer 58 KB
Unused 46%
Monthly Cost €1/mo
Zendesk Widget
Customer Support
Optional
Execution 113ms
Transfer 5 KB
Monthly Cost €1/mo
allbirds.de
Other
Optional
Execution 109ms
Transfer 21 KB
Monthly Cost €1/mo
allbirds.de
Other
Optional
Execution 79ms
Transfer 27 KB
Monthly Cost €0/mo
allbirds.de
Other
Optional
Execution 75ms
Transfer 23 KB
Monthly Cost €0/mo
allbirds.de
Other
Optional
Execution 69ms
Transfer 31 KB
Monthly Cost €0/mo
jsDelivr
CDN
Optional
Execution 66ms
Transfer 43 KB
Unused 65%
Monthly Cost €0/mo
Zendesk Widget
Customer Support
Optional
Execution 56ms
Transfer 5 KB
Monthly Cost €0/mo

These scripts may cost more than they're worth

  • cdn.shopify.com adds 1373ms and costs ~€7/month
  • allbirds.de adds 1040ms and costs ~€6/month
  • Unattributable adds 967ms and costs ~€5/month
  • Zendesk Widget adds 651ms and costs ~€3/month
  • cdn.shopify.com adds 458ms and costs ~€2/month
  • allbirds.de adds 333ms and costs ~€2/month
  • allbirds.de adds 283ms and costs ~€2/month
  • Zendesk Widget adds 233ms 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

cdn.shopify.com takes 1373ms 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

allbirds.de takes 1040ms 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 967ms 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

Zendesk Widget takes 651ms 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

50% 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

cdn.shopify.com takes 458ms 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

allbirds.de takes 333ms 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

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

allbirds.de takes 283ms 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

Zendesk Widget takes 233ms 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

65% of jsDelivr'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.

Send Feedback