Performance
· 17 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.
4.40 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
13.62 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
2.52 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.
6.03 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.
19.45 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 BudgetAction2.3 MB transferred, 304 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
FJS Execution CostAction10281ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 2550ms | 72ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-K46XMWV | 1628ms | 1498ms | 77ms | 3rd |
| https://www.uschamber.com/ | 1131ms | 151ms | 4ms | 3rd |
| https://www.uschamber.com/dist/assets/app-B3_sspq0.js | 1115ms | 235ms | 0ms | 3rd |
| https://js.hs-analytics.net/analytics/1776811800000/50705538.js | 943ms | 697ms | 10ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-JYLFZFS1C9&cx=c>m=4e64h1 | 489ms | 433ms | 50ms | 3rd |
| https://cookie-cdn.cookiepro.com/scripttemplates/202209.2.0/otBannerSdk.js | 479ms | 300ms | 43ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-V7HPP6PE41&cx=c>m=4e64h1 | 329ms | 279ms | 48ms | 3rd |
| https://cms.www.uschamber.com/cpresources/99a3a5d8/datastar.js?v=1776761276 | 238ms | 225ms | 0ms | 3rd |
| https://cdn.parsely.com/keys/uschamber.com/p.js | 191ms | 165ms | 7ms | 3rd |
Showing top 10 of 21 scripts
DJS BundlesAction30 scripts, 437 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/js?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 | 65 KB (41%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-K46XMWV | 169 KB | 59 KB (35%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-950327711 | 148 KB | 55 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 InventoryAction304 resources · 2.3 MB · 437 KB savings availableFIX
~437.3 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 304 resources | 2.3 MiB | ||||||
BImage Optimization40 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 Loading4 fonts (257 KB)PASS
Web fonts
4
257 KB total
Render-blocking
0
of 4
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
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 ~77 KB and ~154 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource Hints4 hints, 0 missing preconnectsPASS
Current Resource Hints
4 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
AHTTP Cachingmax-age=86400 (1 day)PASS
max-age=86400
| Directive | Value | Meaning |
|---|---|---|
| max-age | 86400 | Cache for 1 day |
Network Waterfall304 requests over 2954msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 2550ms | 0 KB | — | €28/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 1628ms | 169 KB | 35% | €18/mo | Costly |
www.uschamber.com www.uschamber.com | Other | 1131ms | 97 KB | — | €12/mo | Costly |
www.uschamber.com www.uschamber.com | Other | 1115ms | 14 KB | — | €12/mo | Costly |
HubSpot Analytics js.hs-analytics.net | Analytics | 943ms | 42 KB | — | €10/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 489ms | 176 KB | 40% | €5/mo | Costly |
cookie-cdn.cookiepro.com cookie-cdn.cookiepro.com | Other | 479ms | 91 KB | 54% | €5/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 329ms | 157 KB | 41% | €4/mo | Costly |
cms.www.uschamber.com cms.www.uschamber.com | Other | 238ms | 14 KB | — | €3/mo | Costly |
cdn.parsely.com cdn.parsely.com | Other | 191ms | 25 KB | — | €2/mo | Optional |
Facebook Pixel connect.facebook.net | Advertising | 188ms | 45 KB | — | €2/mo | Optional |
Facebook Pixel connect.facebook.net | Advertising | 184ms | 97 KB | 35% | €2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 175ms | 148 KB | 37% | €2/mo | Optional |
LinkedIn Insight snap.licdn.com | Advertising | 130ms | 19 KB | — | €1/mo | Optional |
cookie-cdn.cookiepro.com cookie-cdn.cookiepro.com | Other | 97ms | 9 KB | — | €1/mo | Optional |
Twitter/X Pixel static.ads-twitter.com | Advertising | 96ms | 13 KB | — | €1/mo | Optional |
ml314.com ml314.com | Other | 76ms | 39 KB | — | €1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 72ms | 148 KB | 72% | €1/mo | Optional |
tags.srv.stackadapt.com tags.srv.stackadapt.com | Other | 70ms | 8 KB | — | €1/mo | Optional |
www.uschamber.com www.uschamber.com | Other | 50ms | 59 KB | — | €1/mo | Optional |
ml314.com ml314.com | Other | 50ms | 1 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 2550ms and costs ~€28/month
- Google Tag Manager adds 1628ms and costs ~€18/month
- www.uschamber.com adds 1131ms and costs ~€12/month
- www.uschamber.com adds 1115ms and costs ~€12/month
- HubSpot Analytics adds 943ms and costs ~€10/month
- Google Tag Manager adds 489ms and costs ~€5/month
- cookie-cdn.cookiepro.com adds 479ms and costs ~€5/month
- Google Tag Manager adds 329ms and costs ~€4/month
- cms.www.uschamber.com adds 238ms and costs ~€3/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 2550ms 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 1628ms 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 1131ms 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 1115ms 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
HubSpot Analytics takes 943ms 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 489ms 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
cookie-cdn.cookiepro.com takes 479ms 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
Google Tag Manager takes 329ms 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
cms.www.uschamber.com takes 238ms 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
72% of Google Tag Manager'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