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.
1.43 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
6.61 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
109 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.099
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
4.09 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.
6.78 s
Page Load Progression
FPage Weight BudgetAction11.0 MB transferred, 138 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
DJS BundlesAction37 scripts, 466 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 | 145 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 | 55 KB (50%) | ✓ | 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://tr.snapchat.com/config/edu/716534ad-736f-4d7f-9bb5-ab5eb8c419ea.js?v=3.56.0-2604221701 | 0 KB | — | ✓ | 3rd |
| https://analytics.tiktok.com/i18n/pixel/static/identify_5cff1caf.js | 40 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 InventoryAction138 resources · 11.0 MB · 466 KB savings availableFIX
~465.5 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 138 resources | 11.0 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
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
BJS Execution Cost982ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 251ms | 6ms | 0ms | 3rd |
| https://www.stonybrook.edu/ | 224ms | 2ms | 1ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-P43R9T>m_auth=jCHsNovKQBjtTL9y_RXzMQ>m_preview=env-1>m_cookies_win=x | 201ms | 181ms | 16ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-8YXBWVVFPX&cx=c>m=4e64k0 | 105ms | 85ms | 12ms | 3rd |
| https://script.crazyegg.com/pages/versioned/common-scripts/4ce8c7df8d425cc50464576824ed91eb.js | 73ms | 65ms | 4ms | 3rd |
| https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwMQ.js | 69ms | 59ms | 9ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-17129731817&cx=c>m=4e64k0 | 57ms | 49ms | 8ms | 3rd |
A+Text CompressionAll text resources are compressedPASS
A+Font Loading7 fonts (132 KB)PASS
Web fonts
7
132 KB total
Render-blocking
0
of 7
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
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall138 requests over 5059msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 251ms | 0 KB | — | €3/mo | Costly |
www.stonybrook.edu www.stonybrook.edu | Other | 224ms | 18 KB | — | €2/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 201ms | 189 KB | 35% | €2/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 105ms | 177 KB | 38% | €1/mo | Optional |
script.crazyegg.com script.crazyegg.com | Other | 73ms | 55 KB | 53% | €1/mo | Optional |
analytics.tiktok.com analytics.tiktok.com | Other | 69ms | 110 KB | 50% | €1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 57ms | 137 KB | 44% | €1/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 251ms and costs ~€3/month
- www.stonybrook.edu adds 224ms and costs ~€2/month
- Google Tag Manager adds 201ms 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 251ms 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 224ms 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 201ms 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