Performance
· 16 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.
5.20 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
24.53 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
4.40 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.018
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
11.68 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.
37.62 s
Page Load Progression
FPage Weight BudgetAction16.8 MB transferred, 319 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
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 Execution CostAction19229ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 3416ms | 190ms | 0ms | 3rd |
| https://www.allbirds.com/ | 2327ms | 364ms | 59ms | 3rd |
| https://www.allbirds.com/cdn/shop/t/4071/assets/ScrollTrigger.js | 2013ms | 798ms | 1ms | 3rd |
| https://www.allbirds.com/cdn/shop/t/4071/assets/header.js | 1311ms | 932ms | 1ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-736740096&cx=c>m=4e6461h1 | 891ms | 812ms | 70ms | 3rd |
| https://popupform.allbirds.com/w37htfhcq2/vendor/f0ff0959-79f9-4c1e-a197-0361a8f1cbb2/main.js?cb=0036016EDAA80E99066F39CFE5BC2BF2 | 780ms | 533ms | 69ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-TH8KRSBJ | 635ms | 528ms | 98ms | 3rd |
| https://www.allbirds.com/cdn/shop/t/4071/assets/footer.js | 576ms | 379ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-935878905&cx=c>m=4e6461h1 | 505ms | 430ms | 70ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202506.1.0/otBannerSdk.js | 491ms | 318ms | 101ms | 3rd |
Showing top 10 of 37 scripts
FJS BundlesAction167 scripts, 703 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtm.js?id=GTM-TH8KRSBJ | 182 KB | 74 KB (41%) | ✓ | 3rd |
| https://popupform.allbirds.com/w37htfhcq2/vendor/f0ff0959-79f9-4c1e-a197-0361a8f1cbb2/main.js?cb=0036016EDAA80E99066F39CFE5BC2BF2 | 116 KB | 69 KB (59%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/destination?id=G-KB1068K0E6&cx=c>m=4e6461h1 | 169 KB | 68 KB (40%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-786649265&cx=c>m=4e6461h1 | 144 KB | 64 KB (45%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-935878905&cx=c>m=4e6461h1 | 145 KB | 64 KB (44%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-736740096&cx=c>m=4e6461h1 | 144 KB | 64 KB (44%) | ✓ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202506.1.0/otBannerSdk.js | 120 KB | 63 KB (52%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WWZFMZRX | 155 KB | 62 KB (40%) | ✓ | 3rd |
| https://superfiliate-cdn.com/storefront.js?shop=weareallbirds.myshopify.com | 81 KB | 54 KB (67%) | ✓ | 3rd |
| https://www.allbirds.com/cdn/wpm/b0e8c7c7aw41bd75a1p837d7fd4m8b145375m.js | 61 KB | 27 KB (46%) | ✓ | 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
DHTTP CachingActionno-store (uncacheable)FIX
private, no-store
| Directive | Value | Meaning |
|---|---|---|
| private | — | Only browser cache, not CDN/proxy |
| no-store | — | Never cache this response |
BImage Optimization79 images, 0 KB saveableREVIEW
A+Text CompressionAll text resources are compressedPASS
A+Font Loading6 fonts (203 KB)PASS
Web fonts
6
203 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 Hints5 hints, 0 missing preconnectsPASS
Current Resource Hints
5 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall319 requests over 0msINFO
Performance analysis not available for this result.
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 3416ms | 0 KB | — | $20/mo | Costly |
www.allbirds.com www.allbirds.com | Other | 2327ms | 109 KB | — | $13/mo | Costly |
www.allbirds.com www.allbirds.com | Other | 2013ms | 65 KB | 35% | $12/mo | Costly |
www.allbirds.com www.allbirds.com | Other | 1311ms | 7 KB | — | $8/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 891ms | 144 KB | 44% | $5/mo | Costly |
popupform.allbirds.com popupform.allbirds.com | Other | 780ms | 116 KB | 59% | $4/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 635ms | 182 KB | 41% | $4/mo | Costly |
www.allbirds.com www.allbirds.com | Other | 576ms | 2 KB | — | $3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 505ms | 145 KB | 44% | $3/mo | Costly |
OneTrust cdn.cookielaw.org | Consent | 491ms | 120 KB | 52% | $3/mo | Essential |
Google Tag Manager www.googletagmanager.com | Tag Manager | 491ms | 155 KB | 40% | $3/mo | Costly |
www.allbirds.com www.allbirds.com | Other | 468ms | 4 KB | — | $3/mo | Costly |
www.allbirds.com www.allbirds.com | Other | 465ms | 61 KB | 46% | $3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 424ms | 169 KB | 40% | $2/mo | Costly |
cdn.gladly.com cdn.gladly.com | Other | 414ms | 43 KB | — | $2/mo | Costly |
cdn.trackjs.com cdn.trackjs.com | Other | 386ms | 11 KB | — | $2/mo | Costly |
Amplitude cdn.amplitude.com | Analytics | 372ms | 43 KB | — | $2/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 285ms | 144 KB | 45% | $2/mo | Costly |
beacon.riskified.com beacon.riskified.com | Other | 284ms | 17 KB | — | $2/mo | Costly |
www.allbirds.com www.allbirds.com | Other | 275ms | 2 KB | — | $2/mo | Costly |
www.allbirds.com www.allbirds.com | Other | 250ms | 2 KB | — | $1/mo | Costly |
www.allbirds.com www.allbirds.com | Other | 235ms | 3 KB | — | $1/mo | Costly |
www.allbirds.com www.allbirds.com | Other | 233ms | 2 KB | — | $1/mo | Costly |
www.allbirds.com www.allbirds.com | Other | 187ms | 28 KB | — | $1/mo | Optional |
www.allbirds.com www.allbirds.com | Other | 179ms | 21 KB | — | $1/mo | Optional |
superfiliate-cdn.com superfiliate-cdn.com | Other | 151ms | 81 KB | 67% | $1/mo | Optional |
www.allbirds.com www.allbirds.com | Other | 149ms | 2 KB | — | $1/mo | Optional |
www.allbirds.com www.allbirds.com | Other | 145ms | 21 KB | — | $1/mo | Optional |
jssdk.allbirds.com jssdk.allbirds.com | Other | 143ms | 31 KB | — | $1/mo | Optional |
www.allbirds.com www.allbirds.com | Other | 132ms | 23 KB | — | $1/mo | Optional |
www.allbirds.com www.allbirds.com | Other | 115ms | 14 KB | — | $1/mo | Optional |
www.allbirds.com www.allbirds.com | Other | 104ms | 31 KB | — | $1/mo | Optional |
www.allbirds.com www.allbirds.com | Other | 100ms | 4 KB | — | $1/mo | Optional |
www.allbirds.com www.allbirds.com | Other | 91ms | 2 KB | — | $1/mo | Optional |
OneTrust cdn.cookielaw.org | Consent | 85ms | 9 KB | — | $0/mo | Essential |
www.allbirds.com www.allbirds.com | Other | 72ms | 3 KB | — | $0/mo | Optional |
cdn.gladly.com cdn.gladly.com | Other | 52ms | 0 KB | — | $0/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 3416ms and costs ~$20/month
- www.allbirds.com adds 2327ms and costs ~$13/month
- www.allbirds.com adds 2013ms and costs ~$12/month
- www.allbirds.com adds 1311ms and costs ~$8/month
- Google Tag Manager adds 891ms and costs ~$5/month
- popupform.allbirds.com adds 780ms and costs ~$4/month
- Google Tag Manager adds 635ms and costs ~$4/month
- www.allbirds.com adds 576ms and costs ~$3/month
- Google Tag Manager adds 505ms and costs ~$3/month
- Google Tag Manager adds 491ms and costs ~$3/month
- www.allbirds.com adds 468ms and costs ~$3/month
- www.allbirds.com adds 465ms and costs ~$3/month
- Google Tag Manager adds 424ms and costs ~$2/month
- cdn.gladly.com adds 414ms and costs ~$2/month
- cdn.trackjs.com adds 386ms and costs ~$2/month
- Amplitude adds 372ms and costs ~$2/month
- Google Tag Manager adds 285ms and costs ~$2/month
- beacon.riskified.com adds 284ms and costs ~$2/month
- www.allbirds.com adds 275ms and costs ~$2/month
- www.allbirds.com adds 250ms and costs ~$1/month
- www.allbirds.com adds 235ms and costs ~$1/month
- www.allbirds.com adds 233ms and costs ~$1/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 3416ms 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.allbirds.com takes 2327ms 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.allbirds.com takes 2013ms 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.allbirds.com takes 1311ms 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
Google Tag Manager takes 891ms 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
popupform.allbirds.com takes 780ms 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
59% of popupform.allbirds.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
Google Tag Manager takes 635ms 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.allbirds.com takes 576ms 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
Google Tag Manager takes 505ms 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
52% of OneTrust'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
Google Tag Manager takes 491ms 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.allbirds.com takes 468ms 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.allbirds.com takes 465ms 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
Google Tag Manager takes 424ms 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
cdn.gladly.com takes 414ms 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
cdn.trackjs.com takes 386ms 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
Amplitude takes 372ms 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
Google Tag Manager takes 285ms 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
beacon.riskified.com takes 284ms 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.allbirds.com takes 275ms 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.allbirds.com takes 250ms 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.allbirds.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
www.allbirds.com takes 233ms 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
67% of superfiliate-cdn.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