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.
1.91 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.67 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
11 ms
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.
3.55 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.
5.94 s
Page Load Progression
590 ms
1.2 s 1.8 s
2.4 s 3.0 s
3.5 s
4.1 s
4.7 sFPage Weight BudgetAction20.4 MB transferred, 151 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
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 BundlesAction31 scripts, 414 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-NMTFNS313S&cx=c>m=4e64h1 | 156 KB | 68 KB (43%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WHRVJHV | 139 KB | 68 KB (49%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-PDSXF64 | 117 KB | 64 KB (55%) | ✓ | 3rd |
| https://home.dartmouth.edu/sites/home/files/js/js_orPJ7eQR1DqYGkonn0F0w1KPVPTS4YxcPn3VjuOVP28.js?scope=footer&delta=0&language=en&theme=darthome_2021&include=eJx1ikEOwjAMBD9UCPQzHCM3Na4hsZHjVjyfqAgJInFZ7c7sDOYRRHSVhAXF49QWWpj_iGEXq_CGViFHUecrJ3BWiSlze4Zvtv8XLRjH03gOkzEtjjNhJyjrBPlQk_HDayc3LqgDqVLGmCqGd23tAo5WwO4f60CBWvT7CDd4_sLyAhcWYXI | 113 KB | 63 KB (56%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-FDKJ4M25RS&cx=c>m=4e64h1 | 152 KB | 61 KB (40%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-MRK4RQQ | 142 KB | 59 KB (41%) | ✓ | 3rd |
| https://connect.facebook.net/en_US/fbevents.js | 97 KB | 31 KB (32%) | ✓ | 3rd |
| https://js.hs-scripts.com/8382967.js | 1 KB | — | ✓ | 3rd |
| https://f.vimeocdn.com/p/4.46.41/js/vendor.module.js | 93 KB | — | ✓ | 3rd |
| https://home.dartmouth.edu/sites/home/files/js/js_ihZ_RC6byttxafpvZ60R4gczzIOesacI4nczMGYb0oE.js?scope=footer&delta=2&language=en&theme=darthome_2021&include=eJx1ikEOwjAMBD9UCPQzHCM3Na4hsZHjVjyfqAgJInFZ7c7sDOYRRHSVhAXF49QWWpj_iGEXq_CGViFHUecrJ3BWiSlze4Zvtv8XLRjH03gOkzEtjjNhJyjrBPlQk_HDayc3LqgDqVLGmCqGd23tAo5WwO4f60CBWvT7CDd4_sLyAhcWYXI | 9 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 InventoryAction151 resources · 20.4 MB · 414 KB savings availableFIX
~413.7 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 151 resources | 20.4 MiB | ||||||
BImage Optimization71 images, 0 KB saveableREVIEW
CJS Execution CostAction1110ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://home.dartmouth.edu/sites/home/files/js/js_orPJ7eQR1DqYGkonn0F0w1KPVPTS4YxcPn3VjuOVP28.js?scope=footer&delta=0&language=en&theme=darthome_2021&include=eJx1ikEOwjAMBD9UCPQzHCM3Na4hsZHjVjyfqAgJInFZ7c7sDOYRRHSVhAXF49QWWpj_iGEXq_CGViFHUecrJ3BWiSlze4Zvtv8XLRjH03gOkzEtjjNhJyjrBPlQk_HDayc3LqgDqVLGmCqGd23tAo5WwO4f60CBWvT7CDd4_sLyAhcWYXI | 394ms | 103ms | 7ms | 3rd |
| Unattributable | 184ms | 4ms | 0ms | 3rd |
| https://js.hs-analytics.net/analytics/1776803700000/8382967.js | 164ms | 123ms | 3ms | 3rd |
| https://home.dartmouth.edu/ | 160ms | 1ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-MRK4RQQ | 82ms | 70ms | 10ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-NMTFNS313S&cx=c>m=4e64h1 | 69ms | 58ms | 11ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-FDKJ4M25RS&cx=c>m=4e64h1 | 57ms | 46ms | 10ms | 3rd |
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 Loading8 fonts (345 KB)PASS
Web fonts
8
345 KB total
Render-blocking
0
of 8
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
Network Waterfall151 requests over 3767msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
home.dartmouth.edu home.dartmouth.edu | Other | 394ms | 113 KB | 56% | $5/mo | Costly |
Unattributable Unattributable | Other | 184ms | 0 KB | — | $2/mo | Optional |
HubSpot Analytics js.hs-analytics.net | Analytics | 164ms | 46 KB | — | $2/mo | Optional |
home.dartmouth.edu home.dartmouth.edu | Other | 160ms | 41 KB | — | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 82ms | 142 KB | 41% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 69ms | 156 KB | 43% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 57ms | 152 KB | 40% | $1/mo | Optional |
These scripts may cost more than they're worth
- home.dartmouth.edu adds 394ms and costs ~$5/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
home.dartmouth.edu takes 394ms 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
56% of home.dartmouth.edu'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