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.
2.14 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
3.38 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
212 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.002
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
5.96 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.
9.14 s
Page Load Progression
FPage Weight BudgetAction26.3 MB transferred, 208 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
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
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 Execution CostAction2720ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.moma.org/dist/commons.914be26cb6dff3c66d69.js | 605ms | 234ms | 23ms | 3rd |
| Unattributable | 357ms | 10ms | 0ms | 3rd |
| https://www.moma.org/ | 307ms | 16ms | 1ms | 3rd |
| https://www.moma.org/dist/main.7411a40bd3be0d7c184d.js | 201ms | 105ms | 74ms | 3rd |
| https://cdn.us.heap-api.com/v5/heapjs-static/5.3.12/core/heap.js | 148ms | 140ms | 6ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-NHWPNLJ | 127ms | 110ms | 14ms | 3rd |
| https://dev.visualwebsiteoptimizer.com/cdn/edrv/va_gq-d728c477f0f4777c8be7f1f120d0c70b.br.js | 126ms | 84ms | 15ms | 3rd |
| https://t.contentsquare.net/uxa/89d5842b786f4.js | 122ms | 110ms | 10ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-9QE7QKTBJH&cx=c>m=4e64h1 | 115ms | 96ms | 17ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-8QY3201SLC&cx=c>m=4e64h1 | 107ms | 78ms | 28ms | 3rd |
Showing top 10 of 17 scripts
FJS BundlesAction67 scripts, 3.7 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.moma.org/dist/sanity-portable-text.3ab8161e81c75e81f08a.js | 1068 KB | 1045 KB (98%) | ✓ | 3rd |
| https://www.moma.org/dist/overlay-images-initializer.51579758922f3ebfc185.js | 1042 KB | 1038 KB (100%) | ✓ | 3rd |
| https://www.moma.org/dist/main.7411a40bd3be0d7c184d.js | 1225 KB | 990 KB (81%) | ✓ | 3rd |
| https://www.moma.org/dist/commons.914be26cb6dff3c66d69.js | 218 KB | 126 KB (58%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/destination?id=DC-12602964&cx=c>m=4e64h1 | 148 KB | 72 KB (48%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-RG0HEMD55H&cx=c>m=4e64h1 | 173 KB | 66 KB (38%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-8QY3201SLC&cx=c>m=4e64h1 | 174 KB | 66 KB (38%) | ✓ | 3rd |
| https://t.contentsquare.net/uxa/89d5842b786f4.js | 119 KB | 65 KB (55%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-NHWPNLJ | 173 KB | 64 KB (37%) | ✓ | 3rd |
| https://dev.visualwebsiteoptimizer.com/cdn/edrv/va_gq-d728c477f0f4777c8be7f1f120d0c70b.br.js | 97 KB | 64 KB (66%) | ✓ | 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 InventoryAction208 resources · 26.3 MB · 3.7 MB savings availableFIX
~3.7 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 208 resources | 26.3 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction66 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
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 Loading4 fonts (153 KB)PASS
Web fonts
4
153 KB total
Render-blocking
0
of 4
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 Waterfall208 requests over 4461msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.moma.org www.moma.org | Other | 605ms | 218 KB | 58% | $8/mo | Costly |
Unattributable Unattributable | Other | 357ms | 0 KB | — | $5/mo | Costly |
www.moma.org www.moma.org | Other | 307ms | 39 KB | — | $4/mo | Costly |
www.moma.org www.moma.org | Other | 201ms | 1225 KB | 81% | $3/mo | Costly |
cdn.us.heap-api.com cdn.us.heap-api.com | Other | 148ms | 75 KB | 41% | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 127ms | 173 KB | 37% | $2/mo | Optional |
dev.visualwebsiteoptimizer.com dev.visualwebsiteoptimizer.com | Other | 126ms | 97 KB | 66% | $2/mo | Optional |
t.contentsquare.net t.contentsquare.net | Other | 122ms | 119 KB | 55% | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 115ms | 157 KB | 40% | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 107ms | 174 KB | 38% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 99ms | 173 KB | 38% | $1/mo | Optional |
analytics.tiktok.com analytics.tiktok.com | Other | 99ms | 106 KB | 52% | $1/mo | Optional |
Facebook Pixel connect.facebook.net | Advertising | 78ms | 97 KB | 27% | $1/mo | Optional |
www.moma.org www.moma.org | Other | 68ms | 1068 KB | 98% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 55ms | 148 KB | 48% | $1/mo | Optional |
Hotjar script.hotjar.com | Session Replay | 54ms | 57 KB | 63% | $1/mo | Optional |
www.moma.org www.moma.org | Other | 51ms | 0 KB | — | $1/mo | Optional |
These scripts may cost more than they're worth
- www.moma.org adds 605ms and costs ~$8/month
- Unattributable adds 357ms and costs ~$5/month
- www.moma.org adds 307ms and costs ~$4/month
- www.moma.org adds 201ms 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.moma.org takes 605ms 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
58% of www.moma.org'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
Unattributable takes 357ms 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.moma.org takes 307ms 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.moma.org 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
81% of www.moma.org'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
66% of dev.visualwebsiteoptimizer.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
55% of t.contentsquare.net'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
52% 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
98% of www.moma.org'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
63% of Hotjar'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