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.
1.80 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
4.23 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
4 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.
2.63 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.
4.26 s
Page Load Progression
FPage Weight BudgetAction6.2 MB transferred, 169 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
Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.
CSS bundle is large — purge unused styles (PurgeCSS, Tailwind JIT) to reduce CSS payload.
Source: web.dev
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 BundlesAction63 scripts, 542 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.census.gov/etc.clientlibs/census/clientlibs/census-js.min.7052beb2c82575fa30753611019d25e3.js | 152 KB | 118 KB (77%) | ✗ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L&cx=c>m=4e64h1 | 147 KB | 106 KB (72%) | ✓ | 3rd |
| https://www.census.gov/main/resources/js/census.min.js | 150 KB | 86 KB (57%) | ✗ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L | 147 KB | 63 KB (43%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-VY5XG9XWGG | 159 KB | 63 KB (39%) | ✓ | 3rd |
| https://www.census.gov/etc.clientlibs/clientlibs/granite/jquery-ui.min.000478df169ef08edfb24d7502acb3c1.js | 69 KB | 56 KB (81%) | ✓ | 3rd |
| https://assets.adobedtm.com/launch-ENdc1ca6bab15e46a5b880a2c3f9d462ab.min.js | 125 KB | 30 KB (24%) | ✓ | 3rd |
| https://www.census.gov/econ_assets/js/jquery.min.js | 30 KB | 22 KB (73%) | ✓ | 3rd |
| https://www.census.gov/etc.clientlibs/census/components/common/body/censuscontentfragmentlist/clientlibs/component.min.f0b7ea071fe1b43cf4d510ce1f3fec22.js | 1 KB | — | ✓ | 3rd |
| https://www.census.gov/etc.clientlibs/census/clientlibs/clientlib-dependencies.min.d41d8cd98f00b204e9800998ecf8427e.js | 0 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 InventoryAction169 resources · 6.2 MB · 542 KB savings availableFIX
~541.8 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 169 resources | 6.2 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction23 images, 0 KB saveableREVIEW
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
BJS Execution Cost808ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.census.gov/ | 248ms | 32ms | 6ms | 3rd |
| Unattributable | 201ms | 15ms | 0ms | 3rd |
| https://www.census.gov/cdn-cgi/challenge-platform/scripts/jsd/main.js | 146ms | 138ms | 2ms | 3rd |
| https://www.census.gov/main/resources/js/census.min.js | 84ms | 48ms | 13ms | 3rd |
| https://assets.adobedtm.com/launch-ENdc1ca6bab15e46a5b880a2c3f9d462ab.min.js | 74ms | 59ms | 11ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L | 56ms | 47ms | 8ms | 3rd |
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 Loading7 fonts (106 KB)PASS
Web fonts
7
106 KB total
Render-blocking
0
of 7
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 HintsNo optimization neededPASS
Network Waterfall169 requests over 3325msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.census.gov www.census.gov | Other | 248ms | 38 KB | — | $3/mo | Costly |
Unattributable Unattributable | Other | 201ms | 0 KB | — | $3/mo | Costly |
www.census.gov www.census.gov | Other | 146ms | 0 KB | — | $2/mo | Optional |
www.census.gov www.census.gov | Other | 84ms | 150 KB | 57% | $1/mo | Optional |
assets.adobedtm.com assets.adobedtm.com | Other | 74ms | 125 KB | 24% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 56ms | 147 KB | 43% | $1/mo | Optional |
These scripts may cost more than they're worth
- www.census.gov adds 248ms and costs ~$3/month
- Unattributable adds 201ms 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
www.census.gov takes 248ms 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
Unattributable takes 201ms 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
57% of www.census.gov'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