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.
8.91 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
16.13 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
838 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.060
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
12.32 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.
23.37 s
Page Load Progression
FPage Weight BudgetAction4.7 MB transferred, 178 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
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 CostAction6788ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/70362.js | 2594ms | 2516ms | 9ms | 3rd |
| Unattributable | 2190ms | 298ms | 0ms | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/calcite-components/cdn/G7AHLVJ5.js | 525ms | 434ms | 0ms | 3rd |
| https://www.arcgis.com/home/index.html | 393ms | 4ms | 1ms | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/42436.js | 371ms | 254ms | 8ms | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/calcite-components/cdn/M6MCECQO.js | 181ms | 150ms | 0ms | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/25611.js | 156ms | 68ms | 2ms | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-app-components/arcgis-app/p-0b9f6f3d.js | 126ms | 110ms | 0ms | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/calcite-components/cdn/TYCGDLK6.js | 75ms | 69ms | 0ms | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/7315.js | 61ms | 0ms | 1ms | 3rd |
Showing top 10 of 12 scripts
FJS BundlesAction105 scripts, 1.2 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/1565.js | 535 KB | 355 KB (66%) | ✓ | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/42436.js | 309 KB | 237 KB (77%) | ✓ | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/70362.js | 273 KB | 157 KB (58%) | ✓ | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/47313.js | 146 KB | 117 KB (80%) | ✓ | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/882.js | 138 KB | 90 KB (65%) | ✓ | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/3050.js | 64 KB | 50 KB (78%) | ✓ | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/87032.js | 53 KB | 42 KB (80%) | ✓ | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/991.js | 51 KB | 40 KB (80%) | ✓ | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/47209.js | 30 KB | 28 KB (96%) | ✓ | 3rd |
| https://cdn-a.arcgis.com/cdn/1C31855/js/arcgis-online-4.x/build/88395.js | 30 KB | 28 KB (95%) | ✓ | 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 InventoryAction178 resources · 4.7 MB · 1.2 MB savings availableFIX
~1.2 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 178 resources | 4.7 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization19 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
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 Loading3 fonts (97 KB)PASS
Web fonts
3
97 KB total
Render-blocking
0
of 3
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
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall178 requests over 2280msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
cdn-a.arcgis.com cdn-a.arcgis.com | Other | 2594ms | 273 KB | 58% | $34/mo | Costly |
Unattributable Unattributable | Other | 2190ms | 0 KB | — | $29/mo | Costly |
cdn-a.arcgis.com cdn-a.arcgis.com | Other | 525ms | 12 KB | — | $7/mo | Costly |
www.arcgis.com www.arcgis.com | Other | 393ms | 1 KB | — | $5/mo | Costly |
cdn-a.arcgis.com cdn-a.arcgis.com | Other | 371ms | 309 KB | 77% | $5/mo | Costly |
cdn-a.arcgis.com cdn-a.arcgis.com | Other | 181ms | 5 KB | — | $2/mo | Optional |
cdn-a.arcgis.com cdn-a.arcgis.com | Other | 156ms | 60 KB | — | $2/mo | Optional |
cdn-a.arcgis.com cdn-a.arcgis.com | Other | 126ms | 8 KB | — | $2/mo | Optional |
cdn-a.arcgis.com cdn-a.arcgis.com | Other | 75ms | 4 KB | — | $1/mo | Optional |
cdn-a.arcgis.com cdn-a.arcgis.com | Other | 61ms | 39 KB | 61% | $1/mo | Optional |
cdn-a.arcgis.com cdn-a.arcgis.com | Other | 60ms | 3 KB | — | $1/mo | Optional |
cdn-a.arcgis.com cdn-a.arcgis.com | Other | 59ms | 4 KB | — | $1/mo | Optional |
These scripts may cost more than they're worth
- cdn-a.arcgis.com adds 2594ms and costs ~$34/month
- Unattributable adds 2190ms and costs ~$29/month
- cdn-a.arcgis.com adds 525ms and costs ~$7/month
- www.arcgis.com adds 393ms and costs ~$5/month
- cdn-a.arcgis.com adds 371ms and costs ~$5/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
cdn-a.arcgis.com takes 2594ms 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
58% of cdn-a.arcgis.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
Unattributable takes 2190ms 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-a.arcgis.com takes 525ms 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.arcgis.com takes 393ms 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-a.arcgis.com takes 371ms 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
77% of cdn-a.arcgis.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
61% of cdn-a.arcgis.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