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.
717 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
3.76 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
227 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.
1.60 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.
4.69 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 sDPage Weight BudgetAction2.5 MB transferred, 313 requestsFIX
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
DJS Execution CostAction2446ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 686ms | 21ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-K46XMWV | 472ms | 442ms | 17ms | 3rd |
| https://www.uschamber.com/dist/assets/app-B3_sspq0.js | 381ms | 57ms | 0ms | 3rd |
| https://www.uschamber.com/ | 344ms | 44ms | 1ms | 3rd |
| https://js.hs-analytics.net/analytics/1776811800000/50705538.js | 182ms | 123ms | 2ms | 3rd |
| https://www.googletagmanager.com/gtag/destination?id=G-JYLFZFS1C9&cx=c>m=4e64h1 | 129ms | 94ms | 28ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-V7HPP6PE41&cx=c>m=4e64h1 | 106ms | 87ms | 15ms | 3rd |
| https://cookie-cdn.cookiepro.com/scripttemplates/202209.2.0/otBannerSdk.js | 91ms | 57ms | 10ms | 3rd |
| https://connect.facebook.net/signals/config/333719000166425?v=2.9.303&r=stable&domain=www.uschamber.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 | 55ms | 49ms | 5ms | 3rd |
DJS BundlesAction30 scripts, 436 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=AW-950327711&cx=c>m=4e64h1 | 148 KB | 106 KB (72%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/destination?id=G-JYLFZFS1C9&cx=c>m=4e64h1 | 176 KB | 70 KB (40%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-V7HPP6PE41&cx=c>m=4e64h1 | 157 KB | 64 KB (41%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-K46XMWV | 169 KB | 58 KB (34%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-950327711 | 148 KB | 54 KB (37%) | ✓ | 3rd |
| https://cookie-cdn.cookiepro.com/scripttemplates/202209.2.0/otBannerSdk.js | 91 KB | 49 KB (54%) | ✓ | 3rd |
| https://connect.facebook.net/en_US/fbevents.js | 97 KB | 34 KB (35%) | ✓ | 3rd |
| https://snap.licdn.com/li.lms-analytics/insight.min.js | 19 KB | — | ✓ | 3rd |
| https://cms.www.uschamber.com/cpresources/99a3a5d8/datastar.js?v=1776761276 | 14 KB | — | ✓ | 3rd |
| https://cookie-cdn.cookiepro.com/consent/ec4d9899-157a-47c1-92dd-35e4dca94036/ec4d9899-157a-47c1-92dd-35e4dca94036.json | 2 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
FPage Weight InventoryAction313 resources · 2.5 MB · 436 KB savings availableFIX
~436.4 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 313 resources | 2.5 MiB | ||||||
BImage Optimization47 images, 0 KB saveableREVIEW
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 Loading5 fonts (320 KB)PASS
Web fonts
5
320 KB total
Render-blocking
0
of 5
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- 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 ~96 KB and ~192 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
AHTTP Cachingmax-age=86400 (1 day)PASS
max-age=86400
| Directive | Value | Meaning |
|---|---|---|
| max-age | 86400 | Cache for 1 day |
Network Waterfall313 requests over 3551msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 686ms | 0 KB | — | €7/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 472ms | 169 KB | 34% | €5/mo | Costly |
www.uschamber.com www.uschamber.com | Other | 381ms | 14 KB | — | €4/mo | Costly |
www.uschamber.com www.uschamber.com | Other | 344ms | 97 KB | — | €4/mo | Costly |
HubSpot Analytics js.hs-analytics.net | Analytics | 182ms | 42 KB | — | €2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 129ms | 176 KB | 40% | €1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 106ms | 157 KB | 41% | €1/mo | Optional |
cookie-cdn.cookiepro.com cookie-cdn.cookiepro.com | Other | 91ms | 91 KB | 54% | €1/mo | Optional |
Facebook Pixel connect.facebook.net | Advertising | 55ms | 45 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 686ms and costs ~€7/month
- Google Tag Manager adds 472ms and costs ~€5/month
- www.uschamber.com adds 381ms and costs ~€4/month
- www.uschamber.com adds 344ms and costs ~€4/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 686ms 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 472ms 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.uschamber.com takes 381ms 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.uschamber.com takes 344ms 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
54% of cookie-cdn.cookiepro.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