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.
1.09 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.61 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
46 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.010
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.18 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.
2.25 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS BundlesAction19 scripts, 620 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.lanl.gov/_next/static/chunks/0lo4p4.f6y6wl.js | 131 KB | 131 KB (100%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L&cx=c>m=4e64k0 | 147 KB | 106 KB (72%) | ✓ | 3rd |
| https://www.lanl.gov/_next/static/chunks/09r11lnei.a48.js | 133 KB | 75 KB (57%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-WD0986RWM9&cx=c>m=4e64k0 | 160 KB | 64 KB (40%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L | 147 KB | 63 KB (43%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WSKKL6N | 129 KB | 61 KB (48%) | ✓ | 3rd |
| https://www.lanl.gov/_next/static/chunks/03e4iw5~sma3b.js | 79 KB | 52 KB (66%) | ✓ | 3rd |
| https://www.lanl.gov/_next/static/chunks/0mr30_9h44kxm.js | 71 KB | 26 KB (36%) | ✓ | 3rd |
| https://www.lanl.gov/_next/static/chunks/0kvv9024-cy43.js | 29 KB | 23 KB (79%) | ✓ | 3rd |
| https://www.lanl.gov/_next/static/chunks/0fpgzu31bgie5.js | 37 KB | 21 KB (57%) | ✓ | 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 InventoryAction53 resources · 1.9 MB · 620 KB savings availableFIX
~620.2 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 53 resources | 1.9 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CPage Weight BudgetAction1.9 MB transferred, 53 requestsREVIEW
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
BJS Execution Cost731ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.lanl.gov/ | 175ms | 12ms | 19ms | 3rd |
| https://www.lanl.gov/_next/static/chunks/0mr30_9h44kxm.js | 145ms | 127ms | 12ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-WD0986RWM9&cx=c>m=4e64k0 | 98ms | 76ms | 20ms | 3rd |
| Unattributable | 92ms | 4ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L | 77ms | 62ms | 15ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WSKKL6N | 75ms | 60ms | 13ms | 3rd |
| https://www.lanl.gov/_next/static/chunks/04dn2s-x-n~kg.js | 68ms | 68ms | 1ms | 3rd |
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
AImage Optimization15 images, 0 KB saveablePASS
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.
Performance issues directly impact user engagement and conversion rates.
A+Font Loading5 fonts (169 KB)PASS
Web fonts
5
169 KB total
Render-blocking
0
of 5
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 Waterfall53 requests over 2027msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.lanl.gov www.lanl.gov | Other | 175ms | 54 KB | — | $2/mo | Optional |
www.lanl.gov www.lanl.gov | Other | 145ms | 71 KB | 36% | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 98ms | 160 KB | 40% | $1/mo | Optional |
Unattributable Unattributable | Other | 92ms | 0 KB | — | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 77ms | 147 KB | 43% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 75ms | 129 KB | 48% | $1/mo | Optional |
www.lanl.gov www.lanl.gov | Other | 68ms | 8 KB | — | $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