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.
3.20 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
27.38 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
1.92 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.089
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
9.56 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.
32.76 s
Page Load Progression
FPage Weight BudgetAction11.4 MB transferred, 137 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 CostAction5432ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 1161ms | 93ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-P43R9T>m_auth=jCHsNovKQBjtTL9y_RXzMQ>m_preview=env-1>m_cookies_win=x | 817ms | 738ms | 62ms | 3rd |
| https://www.stonybrook.edu/ | 813ms | 8ms | 2ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-8YXBWVVFPX&cx=c>m=4e64k0 | 476ms | 384ms | 49ms | 3rd |
| https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwMQ.js | 272ms | 228ms | 37ms | 3rd |
| https://script.crazyegg.com/pages/versioned/common-scripts/4ce8c7df8d425cc50464576824ed91eb.js | 263ms | 233ms | 12ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-17129731817&cx=c>m=4e64k0 | 250ms | 214ms | 34ms | 3rd |
| https://connect.facebook.net/signals/config/2989407044448886?v=2.9.303&r=stable&domain=www.stonybrook.edu&hme=97937018cefade17726f0472876fc101316b2ce9008a35a6a5a7977d7436151a&ex_m=104%2C205%2C154%2C22%2C72%2C73%2C145%2C68%2C67%2C11%2C162%2C90%2C16%2C138%2C127%2C39%2C75%2C78%2C134%2C159%2C164%2C8%2C4%2C5%2C7%2C6%2C3%2C91%2C101%2C165%2C170%2C219%2C62%2C186%2C187%2C55%2C276%2C30%2C74%2C231%2C230%2C229%2C23%2C33%2C103%2C61%2C10%2C63%2C97%2C98%2C99%2C105%2C130%2C31%2C29%2C132%2C133%2C129%2C128%2C155%2C76%2C158%2C156%2C157%2C50%2C60%2C123%2C15%2C161%2C45%2C263%2C264%2C262%2C26%2C27%2C28%2C48%2C146%2C77%2C112%2C18%2C20%2C44%2C40%2C42%2C41%2C83%2C92%2C96%2C110%2C144%2C147%2C46%2C111%2C24%2C21%2C119%2C69%2C36%2C149%2C148%2C150%2C141%2C139%2C25%2C35%2C59%2C109%2C160%2C70%2C17%2C152%2C114%2C81%2C66%2C19%2C85%2C86%2C116%2C84%2C136%2C135%2C34%2C278%2C293%2C212%2C201%2C202%2C200%2C296%2C288%2C52%2C213%2C107%2C131%2C80%2C121%2C54%2C47%2C49%2C113%2C120%2C126%2C58%2C64%2C151%2C115%2C37%2C32%2C53%2C56%2C100%2C163%2C1%2C124%2C14%2C122%2C12%2C2%2C57%2C93%2C65%2C118%2C89%2C88%2C166%2C167%2C94%2C95%2C9%2C125%2C102%2C51%2C142%2C87%2C79%2C71%2C117%2C106%2C43%2C143%2C0%2C82%2C137%2C140%2C153%2C38%2C108%2C13%2C168%2C228%2C227%2C222%2C224%2C225%2C226%2C223%2C211%2C221%2C233%2C193%2C190%2C191%2C185%2C189%2C192%2C188%2C183%2C316%2C196%2C215%2C184%2C182%2C210%2C235%2C206%2C176%2C177%2C172%2C178%2C175%2C173%2C174%2C171%2C169%2C180%2C181%2C179%2C265%2C315%2C194%2C238%2C239%2C244%2C241%2C243%2C242%2C240%2C237%2C252%2C248%2C249%2C247%2C253%2C250%2C246%2C251%2C245 | 206ms | 177ms | 8ms | 3rd |
| https://www.stonybrook.edu/_resources/js/sb-animations.js | 181ms | 115ms | 5ms | 3rd |
| https://sc-static.net/scevent.min.js | 144ms | 129ms | 5ms | 3rd |
Showing top 10 of 20 scripts
DJS BundlesAction37 scripts, 464 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwOQ.js | 122 KB | 93 KB (77%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-8YXBWVVFPX&cx=c>m=4e64k0 | 177 KB | 67 KB (38%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-P43R9T>m_auth=jCHsNovKQBjtTL9y_RXzMQ>m_preview=env-1>m_cookies_win=x | 189 KB | 67 KB (35%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-861933723 | 144 KB | 62 KB (43%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-17129731817&cx=c>m=4e64k0 | 137 KB | 60 KB (44%) | ✓ | 3rd |
| https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwMQ.js | 110 KB | 53 KB (48%) | ✓ | 3rd |
| https://connect.facebook.net/en_US/fbevents.js | 97 KB | 33 KB (34%) | ✓ | 3rd |
| https://script.crazyegg.com/pages/versioned/common-scripts/4ce8c7df8d425cc50464576824ed91eb.js | 55 KB | 29 KB (53%) | ✓ | 3rd |
| https://px4.ads.linkedin.com/collect?v=2&fmt=js&pid=4229617&time=1776894186235&url=https%3A%2F%2Fwww.stonybrook.edu%2F&e_ipv6=AQLsU3oranJ8lQAAAZ23JZObqtuIoOiKeuOPD2Rkje9RXWmz8AucJf3f0eErkYmGfy7ZQQMTpng_ | 1 KB | — | ✓ | 3rd |
| https://connect.facebook.net/signals/config/380944239711487?v=2.9.303&r=stable&domain=www.stonybrook.edu&hme=97937018cefade17726f0472876fc101316b2ce9008a35a6a5a7977d7436151a&ex_m=104%2C205%2C154%2C22%2C72%2C73%2C145%2C68%2C67%2C11%2C162%2C90%2C16%2C138%2C127%2C39%2C75%2C78%2C134%2C159%2C164%2C8%2C4%2C5%2C7%2C6%2C3%2C91%2C101%2C165%2C170%2C219%2C62%2C186%2C187%2C55%2C276%2C30%2C74%2C231%2C230%2C229%2C23%2C33%2C103%2C61%2C10%2C63%2C97%2C98%2C99%2C105%2C130%2C31%2C29%2C132%2C133%2C129%2C128%2C155%2C76%2C158%2C156%2C157%2C50%2C60%2C123%2C15%2C161%2C45%2C263%2C264%2C262%2C26%2C27%2C28%2C48%2C146%2C77%2C112%2C18%2C20%2C44%2C40%2C42%2C41%2C83%2C92%2C96%2C110%2C144%2C147%2C46%2C111%2C24%2C21%2C119%2C69%2C36%2C149%2C148%2C150%2C141%2C139%2C25%2C35%2C59%2C109%2C160%2C70%2C17%2C152%2C114%2C81%2C66%2C19%2C85%2C86%2C116%2C84%2C136%2C135%2C34%2C278%2C293%2C212%2C201%2C202%2C200%2C296%2C288%2C52%2C213%2C107%2C131%2C80%2C121%2C54%2C47%2C49%2C113%2C120%2C126%2C58%2C64%2C151%2C115%2C37%2C32%2C53%2C56%2C100%2C163%2C1%2C124%2C14%2C122%2C12%2C2%2C57%2C93%2C65%2C118%2C89%2C88%2C166%2C167%2C94%2C95%2C9%2C125%2C102%2C51%2C142%2C87%2C79%2C71%2C117%2C106%2C43%2C143%2C0%2C82%2C137%2C140%2C153%2C38%2C108%2C13%2C168%2C228%2C227%2C222%2C224%2C225%2C226%2C223%2C211%2C221%2C233%2C193%2C190%2C191%2C185%2C189%2C192%2C188%2C183%2C316%2C196%2C215%2C184%2C182%2C210%2C235%2C206%2C176%2C177%2C172%2C178%2C175%2C173%2C174%2C171%2C169%2C180%2C181%2C179%2C265%2C315%2C194%2C238%2C239%2C244%2C241%2C243%2C242%2C240%2C237%2C252%2C248%2C249%2C247%2C253%2C250%2C246%2C251%2C245 | 16 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
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 InventoryAction137 resources · 11.4 MB · 464 KB savings availableFIX
~463.8 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 137 resources | 11.4 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction54 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.
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
A+Text CompressionAll text resources are compressedPASS
A+Font Loading6 fonts (117 KB)PASS
Web fonts
6
117 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 Hints1 hints, 0 missing preconnectsPASS
Current Resource Hints
1 resource hints configured
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 Waterfall137 requests over 5451msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 1161ms | 0 KB | — | €13/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 817ms | 189 KB | 35% | €9/mo | Costly |
www.stonybrook.edu www.stonybrook.edu | Other | 813ms | 18 KB | — | €9/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 476ms | 177 KB | 38% | €5/mo | Costly |
analytics.tiktok.com analytics.tiktok.com | Other | 272ms | 110 KB | 48% | €3/mo | Costly |
script.crazyegg.com script.crazyegg.com | Other | 263ms | 55 KB | 53% | €3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 250ms | 137 KB | 44% | €3/mo | Costly |
Facebook Pixel connect.facebook.net | Advertising | 206ms | 17 KB | — | €2/mo | Costly |
www.stonybrook.edu www.stonybrook.edu | Other | 181ms | 12 KB | — | €2/mo | Optional |
sc-static.net sc-static.net | Other | 144ms | 25 KB | — | €2/mo | Optional |
Facebook Pixel connect.facebook.net | Advertising | 128ms | 97 KB | 34% | €1/mo | Optional |
Facebook Pixel connect.facebook.net | Advertising | 121ms | 46 KB | — | €1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 105ms | 144 KB | 43% | €1/mo | Optional |
analytics.tiktok.com analytics.tiktok.com | Other | 102ms | 122 KB | 77% | €1/mo | Optional |
LinkedIn Insight snap.licdn.com | Advertising | 74ms | 19 KB | — | €1/mo | Optional |
script.crazyegg.com script.crazyegg.com | Other | 72ms | 23 KB | — | €1/mo | Optional |
Google Analytics www.google-analytics.com | Analytics | 71ms | 21 KB | — | €1/mo | Optional |
tags.srv.stackadapt.com tags.srv.stackadapt.com | Other | 66ms | 8 KB | — | €1/mo | Optional |
Facebook Pixel connect.facebook.net | Advertising | 58ms | 17 KB | — | €1/mo | Optional |
www.stonybrook.edu www.stonybrook.edu | Other | 52ms | 8 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 1161ms and costs ~€13/month
- Google Tag Manager adds 817ms and costs ~€9/month
- www.stonybrook.edu adds 813ms and costs ~€9/month
- Google Tag Manager adds 476ms and costs ~€5/month
- analytics.tiktok.com adds 272ms and costs ~€3/month
- script.crazyegg.com adds 263ms and costs ~€3/month
- Google Tag Manager adds 250ms and costs ~€3/month
- Facebook Pixel adds 206ms and costs ~€2/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
Unattributable takes 1161ms 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 817ms 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.stonybrook.edu takes 813ms 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 476ms 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
analytics.tiktok.com takes 272ms 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
script.crazyegg.com takes 263ms 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
53% 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
Google Tag Manager takes 250ms 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
Facebook Pixel takes 206ms 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 analytics.tiktok.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