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.
8.80 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
27.21 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
886 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.003
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
8.80 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.
27.39 s
Page Load Progression
FPage Weight BudgetAction4.8 MB transferred, 85 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
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
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
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction4271ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.llnl.gov/ | 1453ms | 6ms | 4ms | 3rd |
| Unattributable | 1007ms | 7ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L | 644ms | 561ms | 73ms | 3rd |
| https://www.llnl.gov/sites/www/files/js/js_MEw8oE9xi3neG9cgAsKjwho3FHhXukrcADmeP8PWbs0.js?scope=footer&delta=0&language=en&theme=sienna&include=eJxlkFFywzAIRC-kWEfSYIk4ODJoAMXJ7es2tetpvtC-XZgdgRl6Ip4xu2icbcgOyRXynXgK8GGv65oUCxpNHEYRty3c4vFKTXFbID-ZTZo8UE_ERapTC1kUY9HeoA6FoMo0wAzPgE-vxPfd-pWhVq4JqqOCk7DFl3TvI16Owj-JLOzInm59jIyrvakhaL7F9-gUFK1tN-iBaUHu8Z8ejrbBCJkhAkN9OWXbwXVLoH6Hd7LgBGetwEWWy7i1m1Q6l93othYLK45X0SX9fcwH-QJlRaXU | 641ms | 476ms | 101ms | 3rd |
| https://www.llnl.gov/sites/www/files/js/js_k8oXBMlzypWW_AQwngBnyY54k4NQ1OjSMji7E8hppr8.js?scope=footer&delta=2&language=en&theme=sienna&include=eJxlkFFywzAIRC-kWEfSYIk4ODJoAMXJ7es2tetpvtC-XZgdgRl6Ip4xu2icbcgOyRXynXgK8GGv65oUCxpNHEYRty3c4vFKTXFbID-ZTZo8UE_ERapTC1kUY9HeoA6FoMo0wAzPgE-vxPfd-pWhVq4JqqOCk7DFl3TvI16Owj-JLOzInm59jIyrvakhaL7F9-gUFK1tN-iBaUHu8Z8ejrbBCJkhAkN9OWXbwXVLoH6Hd7LgBGetwEWWy7i1m1Q6l93othYLK45X0SX9fcwH-QJlRaXU | 160ms | 55ms | 17ms | 3rd |
| https://www.llnl.gov/sites/www/files/css/css_1hneLw5EaXrWX7-Y2sIa3W4nTldQTzXrwYKkpCP5D3I.css?delta=0&language=en&theme=sienna&include=eJyFUtFu2zAM_CEtGgoM2N8QlM3YbCTREKk4-fvSTbNiq7A-GTqdqbvjoSoZcH2lyaTFSfWUREyt4QbdOLMxacCvtAmbdKUMqZtJBaObDXlSjaqtPUGlXWHDhUa8M8KZb6Q-qGxDAqH1RjMUmhkhZZkuQx4vMOFm7KIw81KLPw9DpqhRO-Zhftc1NLpSE0hYq1NXwpnrMuZJIbi-jK64-HBAs8ae1iHs7CFXsWEShRZ0zR08i9G9Z0DqvqBI4jwccWQIv37-fkQ6Ylxf_vP7PqFn6ItrqEMJd-nWk9vlmUTDJI3i3PqG-YSvePsL8GVlWYLXI3O9PNGPY8i5ZvjoCHhJ4lGSB6qEbVrj49M5vO89CpVEs--uFQ-UWtiw4eJ1XfU5-xM59br1lFlXmkMj3aQqXwmOeOM_58_if89shJdNuNq3VLW7-1yCMtWK8dg7tR_7vj-RrvusQe9exRITKoWd0uEO_uiJX5A3nO15Yw | 89ms | 0ms | 0ms | 3rd |
| https://dap.digitalgov.gov/web-vitals/dist/web-vitals.attribution.iife.js | 86ms | 82ms | 3ms | 3rd |
| https://www.llnl.gov/sites/www/files/css/css_4GgOo88JtCSUl2r1PteeXfdq8RXHLjH5VRSpKiuM3ZU.css?delta=2&language=en&theme=sienna&include=eJyFUtFu2zAM_CEtGgoM2N8QlM3YbCTREKk4-fvSTbNiq7A-GTqdqbvjoSoZcH2lyaTFSfWUREyt4QbdOLMxacCvtAmbdKUMqZtJBaObDXlSjaqtPUGlXWHDhUa8M8KZb6Q-qGxDAqH1RjMUmhkhZZkuQx4vMOFm7KIw81KLPw9DpqhRO-Zhftc1NLpSE0hYq1NXwpnrMuZJIbi-jK64-HBAs8ae1iHs7CFXsWEShRZ0zR08i9G9Z0DqvqBI4jwccWQIv37-fkQ6Ylxf_vP7PqFn6ItrqEMJd-nWk9vlmUTDJI3i3PqG-YSvePsL8GVlWYLXI3O9PNGPY8i5ZvjoCHhJ4lGSB6qEbVrj49M5vO89CpVEs--uFQ-UWtiw4eJ1XfU5-xM59br1lFlXmkMj3aQqXwmOeOM_58_if89shJdNuNq3VLW7-1yCMtWK8dg7tR_7vj-RrvusQe9exRITKoWd0uEO_uiJX5A3nO15Yw | 66ms | 0ms | 0ms | 3rd |
| https://static.cloudflareinsights.com/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da1771523124516 | 66ms | 39ms | 5ms | 3rd |
| https://dap.digitalgov.gov/Universal-Federated-Analytics-Min.js?agency=DOE&subagency=LLNL&sdor=fda.gov&dclink=true | 58ms | 49ms | 8ms | 3rd |
DPage Weight InventoryAction85 resources · 4.8 MB · 186 KB savings availableFIX
~185.6 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 85 resources | 4.8 MiB | ||||||
CImage OptimizationAction26 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.
Performance issues directly impact user engagement and conversion rates.
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
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
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
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
CJS BundlesAction20 scripts, 186 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.llnl.gov/sites/www/files/js/js_MEw8oE9xi3neG9cgAsKjwho3FHhXukrcADmeP8PWbs0.js?scope=footer&delta=0&language=en&theme=sienna&include=eJxlkFFywzAIRC-kWEfSYIk4ODJoAMXJ7es2tetpvtC-XZgdgRl6Ip4xu2icbcgOyRXynXgK8GGv65oUCxpNHEYRty3c4vFKTXFbID-ZTZo8UE_ERapTC1kUY9HeoA6FoMo0wAzPgE-vxPfd-pWhVq4JqqOCk7DFl3TvI16Owj-JLOzInm59jIyrvakhaL7F9-gUFK1tN-iBaUHu8Z8ejrbBCJkhAkN9OWXbwXVLoH6Hd7LgBGetwEWWy7i1m1Q6l93othYLK45X0SX9fcwH-QJlRaXU | 155 KB | 105 KB (68%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-CSLL4ZEK4L | 147 KB | 60 KB (41%) | ✓ | 3rd |
| https://www.llnl.gov/sites/www/files/js/js_k8oXBMlzypWW_AQwngBnyY54k4NQ1OjSMji7E8hppr8.js?scope=footer&delta=2&language=en&theme=sienna&include=eJxlkFFywzAIRC-kWEfSYIk4ODJoAMXJ7es2tetpvtC-XZgdgRl6Ip4xu2icbcgOyRXynXgK8GGv65oUCxpNHEYRty3c4vFKTXFbID-ZTZo8UE_ERapTC1kUY9HeoA6FoMo0wAzPgE-vxPfd-pWhVq4JqqOCk7DFl3TvI16Owj-JLOzInm59jIyrvakhaL7F9-gUFK1tN-iBaUHu8Z8ejrbBCJkhAkN9OWXbwXVLoH6Hd7LgBGetwEWWy7i1m1Q6l93othYLK45X0SX9fcwH-QJlRaXU | 29 KB | 20 KB (69%) | ✓ | 3rd |
| https://www.youtube.com/s/_/ytembeds/_/js/k=ytembeds.base.en_US.5f0apfZzpOA.2021.O/am=AAAABA/d=1/exm=base,root/ed=1/br=1/rs=AGKMywFg3MG1UeKh8ePjbhY_YEMv-NHjmA/m=r78Drb | 0 KB | — | ✓ | 3rd |
| https://www.youtube.com/s/player/1bb6ee63/player_embed_es6.vflset/en_US/base.js | 0 KB | — | ✓ | 3rd |
| https://static.cloudflareinsights.com/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da1771523124516 | 0 KB | — | ✓ | 3rd |
| https://www.youtube.com/s/_/ytembeds/_/js/k=ytembeds.base.en_US.5f0apfZzpOA.2021.O/am=AAAABA/d=1/br=1/rs=AGKMywFg3MG1UeKh8ePjbhY_YEMv-NHjmA/m=root,base | 140 KB | — | ✓ | 3rd |
| https://www.youtube.com/s/player/1bb6ee63/player_embed_es6.vflset/en_US/base.js | 436 KB | — | ✓ | 3rd |
| https://www.youtube.com/iframe_api | 3 KB | — | ✓ | 3rd |
| https://static.doubleclick.net/instream/ad_status.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
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
BHTTP Cachingno-cacheREVIEW
no-cache
| Directive | Value | Meaning |
|---|---|---|
| no-cache | — | Cache but always revalidate first |
A+Text CompressionAll text resources are compressedPASS
A+Font Loading9 fonts (822 KB)PASS
Web fonts
9
822 KB total
Render-blocking
0
of 9
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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)
Fixing the unchecked items could save ~335 KB and ~670 ms
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 Waterfall85 requests over 7616msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.llnl.gov www.llnl.gov | Other | 1453ms | 23 KB | — | $19/mo | Costly |
Unattributable Unattributable | Other | 1007ms | 0 KB | — | $13/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 644ms | 147 KB | 41% | $9/mo | Costly |
www.llnl.gov www.llnl.gov | Other | 641ms | 155 KB | 68% | $9/mo | Costly |
www.llnl.gov www.llnl.gov | Other | 160ms | 29 KB | 69% | $2/mo | Optional |
www.llnl.gov www.llnl.gov | Other | 89ms | 86 KB | — | $1/mo | Optional |
dap.digitalgov.gov dap.digitalgov.gov | Other | 86ms | 4 KB | — | $1/mo | Optional |
www.llnl.gov www.llnl.gov | Other | 66ms | 51 KB | — | $1/mo | Optional |
static.cloudflareinsights.com static.cloudflareinsights.com | Other | 66ms | 0 KB | — | $1/mo | Optional |
dap.digitalgov.gov dap.digitalgov.gov | Other | 58ms | 9 KB | — | $1/mo | Optional |
These scripts may cost more than they're worth
- www.llnl.gov adds 1453ms and costs ~$19/month
- Unattributable adds 1007ms and costs ~$13/month
- Google Tag Manager adds 644ms and costs ~$9/month
- www.llnl.gov adds 641ms and costs ~$9/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.llnl.gov takes 1453ms 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 1007ms 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 644ms 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.llnl.gov takes 641ms 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
68% of www.llnl.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
69% of www.llnl.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