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.
1.45 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.99 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
7 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.
1.55 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.
3.12 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 sFPage Weight BudgetAction3.0 MB transferred, 162 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 BundlesAction98 scripts, 626 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.stlouisfed.org/-/media/base-themes/core-libraries/scripts/fullcalendar.js | 174 KB | 117 KB (67%) | ✗ | 3rd |
| https://www.stlouisfed.org/-/media/base-themes/core-libraries/scripts/xaquery.js | 138 KB | 107 KB (78%) | ✗ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-MSPJ5D0SE7&cx=c>m=4e64h1 | 171 KB | 69 KB (40%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-M3GP7HP | 165 KB | 67 KB (41%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-1029333784&cx=c>m=4e64h1 | 138 KB | 62 KB (45%) | ✓ | 3rd |
| https://www.stlouisfed.org/-/media/base-themes/core-libraries/scripts/mediaelement-and-player.js | 73 KB | 59 KB (81%) | ✗ | 3rd |
| https://www.stlouisfed.org/x9jQPH/T/c/Q_3ojO9IFg/uODOmNtGzJJmkbYmt3/T2MwUgIy/cD5kEiN/aZjwB | 174 KB | 38 KB (22%) | ✓ | 3rd |
| https://www.stlouisfed.org/-/media/base-themes/core-libraries/scripts/moment.js | 41 KB | 29 KB (71%) | ✗ | 3rd |
| https://script.crazyegg.com/pages/versioned/common-scripts/4ce8c7df8d425cc50464576824ed91eb.js | 55 KB | 29 KB (52%) | ✓ | 3rd |
| https://www.stlouisfed.org/-/media/base-themes/core-libraries/scripts/galleria-157.js | 30 KB | 28 KB (92%) | ✓ | 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 InventoryAction162 resources · 3.0 MB · 626 KB savings availableFIX
~626.1 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 162 resources | 3.0 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization27 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
BJS Execution Cost734ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 168ms | 6ms | 0ms | 3rd |
| https://www.stlouisfed.org/x9jQPH/T/c/Q_3ojO9IFg/uODOmNtGzJJmkbYmt3/T2MwUgIy/cD5kEiN/aZjwB | 149ms | 135ms | 9ms | 3rd |
| https://www.stlouisfed.org/ | 134ms | 8ms | 3ms | 3rd |
| https://script.crazyegg.com/pages/versioned/common-scripts/4ce8c7df8d425cc50464576824ed91eb.js | 94ms | 79ms | 8ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-M3GP7HP | 73ms | 58ms | 10ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-MSPJ5D0SE7&cx=c>m=4e64h1 | 59ms | 45ms | 10ms | 3rd |
| https://www.stlouisfed.org/-/media/base-themes/core-libraries/scripts/xaquery.js | 57ms | 39ms | 13ms | 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 Loading6 fonts (240 KB)PASS
Web fonts
6
240 KB total
Render-blocking
0
of 6
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 Waterfall162 requests over 2619msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 168ms | 0 KB | — | $2/mo | Optional |
www.stlouisfed.org www.stlouisfed.org | Other | 149ms | 0 KB | 22% | $2/mo | Optional |
www.stlouisfed.org www.stlouisfed.org | Other | 134ms | 497 KB | — | $2/mo | Optional |
script.crazyegg.com script.crazyegg.com | Other | 94ms | 55 KB | 52% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 73ms | 165 KB | 41% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 59ms | 171 KB | 40% | $1/mo | Optional |
www.stlouisfed.org www.stlouisfed.org | Other | 57ms | 138 KB | 78% | $1/mo | Optional |
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
52% of script.crazyegg.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
78% of www.stlouisfed.org'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