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.
2.88 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
26.77 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
3.53 s
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.
8.39 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.
27.10 s
Page Load Progression
FPage Weight BudgetAction9.5 MB transferred, 132 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 Execution CostAction8250ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.nyu.edu/ | 1407ms | 11ms | 3ms | 3rd |
| Unattributable | 1029ms | 251ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-YKLBDQJ61W&cx=c>m=4e64h1 | 1020ms | 883ms | 49ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-5VD495 | 947ms | 845ms | 69ms | 3rd |
| https://cmp.osano.com/O0ob8QmY5Y/5d77d930-221b-4da2-b842-2f4fa04d53c2/osano.js | 566ms | 464ms | 25ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-9CWXCZX89G&cx=c>m=4e64h1 | 261ms | 156ms | 49ms | 3rd |
| https://www.nyu.edu/etc.clientlibs/nyucore/clientlibs/clientlib-site.js | 258ms | 33ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-16640807666&cx=c>m=4e64h1 | 227ms | 170ms | 56ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-H4KKXQKFSM&cx=c>m=4e64h1 | 224ms | 159ms | 62ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-S194DLZYBD&cx=c>m=4e64h1 | 211ms | 161ms | 49ms | 3rd |
Showing top 10 of 25 scripts
FJS BundlesAction49 scripts, 1.1 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtm.js?id=GTM-5VD495 | 202 KB | 76 KB (38%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-H4KKXQKFSM&cx=c>m=4e64h1 | 172 KB | 69 KB (40%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-8Y5XM9YCFW&cx=c>m=4e64h1 | 153 KB | 65 KB (42%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-9CWXCZX89G&cx=c>m=4e64h1 | 153 KB | 65 KB (42%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-VR2BFTJ92R&cx=c>m=4e64h1 | 153 KB | 64 KB (42%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-16640816000&cx=c>m=4e64h1 | 137 KB | 64 KB (47%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-16834589110&cx=c>m=4e64h1 | 137 KB | 64 KB (47%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-YKLBDQJ61W&cx=c>m=4e64h1 | 156 KB | 64 KB (41%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-16640712836&cx=c>m=4e64h1 | 137 KB | 64 KB (47%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-S194DLZYBD&cx=c>m=4e64h1 | 155 KB | 63 KB (41%) | ✓ | 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 InventoryAction132 resources · 9.5 MB · 1.1 MB savings availableFIX
~1.1 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 132 resources | 9.5 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction21 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
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 Loading2 fonts (450 KB)PASS
Web fonts
2
450 KB total
Render-blocking
0
of 2
Dominant font-display
swap
Most common across fonts
Font loading timeline
- 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 ~198 KB and ~396 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 Waterfall132 requests over 3409msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.nyu.edu www.nyu.edu | Other | 1407ms | 0 KB | — | $19/mo | Costly |
Unattributable Unattributable | Other | 1029ms | 0 KB | — | $14/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 1020ms | 156 KB | 41% | $14/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 947ms | 202 KB | 38% | $13/mo | Costly |
cmp.osano.com cmp.osano.com | Other | 566ms | 72 KB | 61% | $8/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 261ms | 153 KB | 42% | $3/mo | Costly |
www.nyu.edu www.nyu.edu | Other | 258ms | 8 KB | — | $3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 227ms | 137 KB | 46% | $3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 224ms | 172 KB | 40% | $3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 211ms | 155 KB | 41% | $3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 199ms | 153 KB | 42% | $3/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 195ms | 153 KB | 42% | $3/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 192ms | 129 KB | 48% | $3/mo | Optional |
OneTrust cdn.cookielaw.org | Consent | 170ms | 9 KB | — | $2/mo | Essential |
Google Tag Manager www.googletagmanager.com | Tag Manager | 169ms | 150 KB | 42% | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 161ms | 129 KB | 48% | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 147ms | 137 KB | 47% | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 144ms | 137 KB | 47% | $2/mo | Optional |
www.nyu.edu www.nyu.edu | Other | 138ms | 22 KB | — | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 129ms | 137 KB | 47% | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 120ms | 129 KB | 48% | $2/mo | Optional |
OneTrust cdn.cookielaw.org | Consent | 117ms | 114 KB | 55% | $2/mo | Essential |
Google Tag Manager www.googletagmanager.com | Tag Manager | 108ms | 129 KB | 48% | $1/mo | Optional |
player.vimeo.com player.vimeo.com | Other | 59ms | 9 KB | — | $1/mo | Optional |
www.nyu.edu www.nyu.edu | Other | 52ms | 2 KB | — | $1/mo | Optional |
These scripts may cost more than they're worth
- www.nyu.edu adds 1407ms and costs ~$19/month
- Unattributable adds 1029ms and costs ~$14/month
- Google Tag Manager adds 1020ms and costs ~$14/month
- Google Tag Manager adds 947ms and costs ~$13/month
- cmp.osano.com adds 566ms and costs ~$8/month
- Google Tag Manager adds 261ms and costs ~$3/month
- www.nyu.edu adds 258ms and costs ~$3/month
- Google Tag Manager adds 227ms and costs ~$3/month
- Google Tag Manager adds 224ms and costs ~$3/month
- Google Tag Manager adds 211ms and costs ~$3/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.nyu.edu takes 1407ms 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 1029ms 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 1020ms 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 947ms 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
cmp.osano.com takes 566ms 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
61% of cmp.osano.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 261ms 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.nyu.edu takes 258ms 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 227ms 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 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 211ms 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
55% of OneTrust'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