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.
4.44 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
10.36 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
270 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.
6.36 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.
10.41 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization47 images, 0 KB saveableREVIEW
CJS Execution CostAction1943ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.migrationpolicy.org/cdn-cgi/scripts/7d0fa10a/cloudflare-static/rocket-loader.min.js | 525ms | 285ms | 7ms | 3rd |
| https://www.migrationpolicy.org/cdn-cgi/challenge-platform/scripts/jsd/main.js | 399ms | 371ms | 7ms | 3rd |
| Unattributable | 345ms | 7ms | 0ms | 3rd |
| https://www.migrationpolicy.org/ | 286ms | 27ms | 2ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-G6BWCDB2NE&cx=c>m=4e64k1 | 226ms | 193ms | 31ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-TPSKCBM | 164ms | 125ms | 31ms | 3rd |
CJS BundlesAction34 scripts, 182 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-G6BWCDB2NE&cx=c>m=4e64k1 | 154 KB | 65 KB (42%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-TPSKCBM | 131 KB | 64 KB (49%) | ✓ | 3rd |
| https://ajax.googleapis.com/ajax/libs/jqueryui/1.10.2/jquery-ui.min.js | 60 KB | 53 KB (90%) | ✓ | 3rd |
| https://www.migrationpolicy.org/sites/default/files/advagg_js/js__pjTsfSkMMhpRGF8yJs-_sJS9VcYoDbSgqSqmUkjKflU__lLhpozcjNhL7OFv2Tq1qDxU7T9PcL1wVqzCwjkYMWvo__kyNmy6x2xOLOA33wEz7GjC-C-UE98mxFHlJDFfhXUNg.js | 2 KB | — | ✓ | 3rd |
| https://www.migrationpolicy.org/sites/default/files/advagg_js/js__2f9xlBegWNSpJHq0LtHL1Y3fozsUt4WQn7unfk8LExI__nodL71snsZr2KzTvNDqSYCZl0OyM1lWFKG_zwHdJAk0__kyNmy6x2xOLOA33wEz7GjC-C-UE98mxFHlJDFfhXUNg.js | 4 KB | — | ✓ | 3rd |
| https://www.migrationpolicy.org/sites/default/files/advagg_js/js__Gd0f7Gamar7qy49d9FeUr2K6SxoG88VLSmjka2FZox4__tX3cxwhdLWgcdGi3FPIBXDksnxTt4FO0WtMMYPGSYJ8__kyNmy6x2xOLOA33wEz7GjC-C-UE98mxFHlJDFfhXUNg.js | 6 KB | — | ✗ | 3rd |
| https://www.migrationpolicy.org/sites/default/files/advagg_js/js__vQIXO4Bzk55YCNsg1V5-apkrqk5_jF4d1tS8hBgimyU__de5oXnkYcxuz2a2ky_mkQ2km-MVMM47pq96OTUSP1cg__kyNmy6x2xOLOA33wEz7GjC-C-UE98mxFHlJDFfhXUNg.js | 14 KB | — | ✗ | 3rd |
| https://www.migrationpolicy.org/sites/default/files/advagg_js/js__tZaPWNsxV0YnLWLQ14MCclXF0_atjBOGD8nknubNfFA__dpyA3lyNrNZYJs-jYAly_VXm5Kcn2noHJsPFCClPZlw__kyNmy6x2xOLOA33wEz7GjC-C-UE98mxFHlJDFfhXUNg.js | 3 KB | — | ✓ | 3rd |
| https://www.migrationpolicy.org/sites/default/files/advagg_js/js__g6mKbcakHxQkz4ZHYaxdO_xqONINvRMgsHh1zAK-fr0__ATHtEmHaeZ0jidpGU22EkhmPDBSgjD8z0bVDQMI-BIY__kyNmy6x2xOLOA33wEz7GjC-C-UE98mxFHlJDFfhXUNg.js | 2 KB | — | ✓ | 3rd |
| https://www.migrationpolicy.org/sites/default/files/advagg_js/js__3PyHVp_4SRq6pNQOBF08IE7KMR78aq2RPCDHv-23ni8__jnBy3voieCOrT5mS-H2uMYWYMPWls4qT80FsxpVYpiw__kyNmy6x2xOLOA33wEz7GjC-C-UE98mxFHlJDFfhXUNg.js | 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
APage Weight Budget1.0 MB transferred, 119 requestsPASS
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
A+Text CompressionAll text resources are compressedPASS
A+Font Loading4 fonts (53 KB)PASS
Web fonts
4
53 KB total
Render-blocking
0
of 4
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
APage Weight Inventory119 resources · 1.0 MB · 182 KB savings availablePASS
~182.0 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 119 resources | 1.0 MiB | ||||||
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall119 requests over 4004msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.migrationpolicy.org www.migrationpolicy.org | Other | 525ms | 4 KB | — | $7/mo | Costly |
www.migrationpolicy.org www.migrationpolicy.org | Other | 399ms | 0 KB | — | $5/mo | Costly |
Unattributable Unattributable | Other | 345ms | 0 KB | — | $5/mo | Costly |
www.migrationpolicy.org www.migrationpolicy.org | Other | 286ms | 25 KB | — | $4/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 226ms | 154 KB | 42% | $3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 164ms | 131 KB | 49% | $2/mo | Optional |
These scripts may cost more than they're worth
- www.migrationpolicy.org adds 525ms and costs ~$7/month
- www.migrationpolicy.org adds 399ms and costs ~$5/month
- Unattributable adds 345ms and costs ~$5/month
- www.migrationpolicy.org adds 286ms and costs ~$4/month
- Google Tag Manager adds 226ms 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.migrationpolicy.org 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.migrationpolicy.org takes 399ms 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 345ms 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.migrationpolicy.org takes 286ms 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 226ms 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