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.
707 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.39 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
104 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.001
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.87 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.
2.93 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
DPage Weight InventoryAction70 resources · 1.6 MB · 289 KB savings availableFIX
~288.6 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 70 resources | 1.6 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CPage Weight BudgetAction1.6 MB transferred, 70 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
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
BImage Optimization26 images, 0 KB saveableREVIEW
Set explicit width and height to prevent CLS.
Performance issues directly impact user engagement and conversion rates.
CJS Execution CostAction1430ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.threadless.com/ | 624ms | 15ms | 1ms | 3rd |
| Unattributable | 151ms | 7ms | 0ms | 3rd |
| https://www.threadless.com/wrjj/ | 132ms | 109ms | 18ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-WHSLYJRBDP&cx=c>m=4e64k0 | 127ms | 97ms | 19ms | 3rd |
| https://connect.facebook.net/signals/config/571177840158185?v=2.9.303&r=stable&domain=www.threadless.com&hme=97937018cefade17726f0472876fc101316b2ce9008a35a6a5a7977d7436151a&ex_m=104%2C205%2C154%2C22%2C72%2C73%2C145%2C68%2C67%2C11%2C162%2C90%2C16%2C138%2C127%2C39%2C75%2C78%2C134%2C159%2C164%2C8%2C4%2C5%2C7%2C6%2C3%2C91%2C101%2C165%2C170%2C219%2C62%2C186%2C187%2C55%2C276%2C30%2C74%2C231%2C230%2C229%2C23%2C33%2C103%2C61%2C10%2C63%2C97%2C98%2C99%2C105%2C130%2C31%2C29%2C132%2C133%2C129%2C128%2C155%2C76%2C158%2C156%2C157%2C50%2C60%2C123%2C15%2C161%2C45%2C263%2C264%2C262%2C26%2C27%2C28%2C48%2C146%2C77%2C112%2C18%2C20%2C44%2C40%2C42%2C41%2C83%2C92%2C96%2C110%2C144%2C147%2C46%2C111%2C24%2C21%2C119%2C69%2C36%2C149%2C148%2C150%2C141%2C139%2C25%2C35%2C59%2C109%2C160%2C70%2C17%2C152%2C114%2C81%2C66%2C19%2C85%2C86%2C116%2C84%2C136%2C135%2C34%2C278%2C293%2C212%2C201%2C202%2C200%2C296%2C288%2C52%2C213%2C107%2C131%2C80%2C121%2C54%2C47%2C49%2C113%2C120%2C126%2C58%2C64%2C151%2C115%2C37%2C32%2C53%2C56%2C100%2C163%2C1%2C124%2C14%2C122%2C12%2C2%2C57%2C93%2C65%2C118%2C89%2C88%2C166%2C167%2C94%2C95%2C9%2C125%2C102%2C51%2C142%2C87%2C79%2C71%2C117%2C106%2C43%2C143%2C0%2C82%2C137%2C140%2C153%2C38%2C108%2C13%2C168 | 119ms | 103ms | 15ms | 3rd |
| https://www.threadless.com/cdn-cgi/scripts/7d0fa10a/cloudflare-static/rocket-loader.min.js | 108ms | 87ms | 4ms | 3rd |
| https://www.threadless.com/cdn-cgi/challenge-platform/scripts/jsd/main.js | 96ms | 92ms | 1ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-MCSQ99 | 73ms | 54ms | 18ms | 3rd |
CJS BundlesAction19 scripts, 289 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-WHSLYJRBDP&cx=c>m=4e64k0 | 178 KB | 69 KB (39%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-MCSQ99 | 146 KB | 65 KB (44%) | ✓ | 3rd |
| https://www.threadless.com/wrjj/ | 175 KB | 63 KB (36%) | ✓ | 3rd |
| https://connect.facebook.net/signals/config/571177840158185?v=2.9.303&r=stable&domain=www.threadless.com&hme=97937018cefade17726f0472876fc101316b2ce9008a35a6a5a7977d7436151a&ex_m=104%2C205%2C154%2C22%2C72%2C73%2C145%2C68%2C67%2C11%2C162%2C90%2C16%2C138%2C127%2C39%2C75%2C78%2C134%2C159%2C164%2C8%2C4%2C5%2C7%2C6%2C3%2C91%2C101%2C165%2C170%2C219%2C62%2C186%2C187%2C55%2C276%2C30%2C74%2C231%2C230%2C229%2C23%2C33%2C103%2C61%2C10%2C63%2C97%2C98%2C99%2C105%2C130%2C31%2C29%2C132%2C133%2C129%2C128%2C155%2C76%2C158%2C156%2C157%2C50%2C60%2C123%2C15%2C161%2C45%2C263%2C264%2C262%2C26%2C27%2C28%2C48%2C146%2C77%2C112%2C18%2C20%2C44%2C40%2C42%2C41%2C83%2C92%2C96%2C110%2C144%2C147%2C46%2C111%2C24%2C21%2C119%2C69%2C36%2C149%2C148%2C150%2C141%2C139%2C25%2C35%2C59%2C109%2C160%2C70%2C17%2C152%2C114%2C81%2C66%2C19%2C85%2C86%2C116%2C84%2C136%2C135%2C34%2C278%2C293%2C212%2C201%2C202%2C200%2C296%2C288%2C52%2C213%2C107%2C131%2C80%2C121%2C54%2C47%2C49%2C113%2C120%2C126%2C58%2C64%2C151%2C115%2C37%2C32%2C53%2C56%2C100%2C163%2C1%2C124%2C14%2C122%2C12%2C2%2C57%2C93%2C65%2C118%2C89%2C88%2C166%2C167%2C94%2C95%2C9%2C125%2C102%2C51%2C142%2C87%2C79%2C71%2C117%2C106%2C43%2C143%2C0%2C82%2C137%2C140%2C153%2C38%2C108%2C13%2C168 | 127 KB | 37 KB (29%) | ✓ | 3rd |
| https://connect.facebook.net/en_US/fbevents.js | 97 KB | 34 KB (36%) | ✓ | 3rd |
| https://cdn-media.threadless.com/static_11/js/base.314582382db5.js | 29 KB | 21 KB (74%) | ✓ | 3rd |
| https://cdn-media.threadless.com/static_11/platform_likes/_SaveFollow.2d2823ea59ac.js | 2 KB | — | ✓ | 3rd |
| https://cdn-media.threadless.com/static_11/js/base_anon.1ef7058cc16d.js | 3 KB | — | ✓ | 3rd |
| https://googleads.g.doubleclick.net/pagead/viewthroughconversion/868006678/?random=1776890851329&cv=11&fst=1776890851329&bg=ffffff&guid=ON&async=1&en=gtag.config>m=45g92e64k1h2v9164638589za204zd9164638589xec&gcd=13l3l3l3l1l1&dma=0&tag_exp=0~115938466~115938469~117266400~117384405~117512542&u_w=800&u_h=600&url=https%3A%2F%2Fwww.threadless.com%2F&rcb=5&frm=0&tiba=Up%20to%2035%25%20Off%20Everything%20at%20Threadless&did=dYzg1YT&gdid=dYzg1YT.dNzQzZD&hn=www.googleadservices.com&npa=0&pscdl=noapi&auid=124353949.1776890851&uaa=x86&uab=64&uafvl=Not-A.Brand%3B24.0.0.0%7CChromium%3B146.0.7680.164&uamb=0&uam=&uap=macOS&uapv=10.15.7&uaw=0&data=event%3Dgtag.config&gap.gtb=1&rfmt=3&fmt=4 | 2 KB | — | ✓ | 3rd |
| https://cdn-media.threadless.com/static_11/js/payment_buttons.1df930d69f19.js | 7 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
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 Loading4 fonts (349 KB)PASS
Web fonts
4
349 KB total
Render-blocking
0
of 4
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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 ~136 KB and ~272 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall70 requests over 3513msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.threadless.com www.threadless.com | Other | 624ms | 26 KB | — | $8/mo | Costly |
Unattributable Unattributable | Other | 151ms | 0 KB | — | $2/mo | Optional |
www.threadless.com www.threadless.com | Other | 132ms | 175 KB | 36% | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 127ms | 178 KB | 39% | $2/mo | Optional |
Facebook Pixel connect.facebook.net | Advertising | 119ms | 127 KB | 29% | $2/mo | Optional |
www.threadless.com www.threadless.com | Other | 108ms | 4 KB | — | $1/mo | Optional |
www.threadless.com www.threadless.com | Other | 96ms | 0 KB | — | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 73ms | 146 KB | 44% | $1/mo | Optional |
These scripts may cost more than they're worth
- www.threadless.com adds 624ms and costs ~$8/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
www.threadless.com takes 624ms 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