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.
7.83 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
15.56 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
597 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.
7.83 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.
15.56 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
DJS Execution CostAction2084ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.rpi.edu/ | 379ms | 6ms | 1ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-TTXBMVKEJW&cx=c>m=4e64k0h2 | 363ms | 302ms | 59ms | 3rd |
| Unattributable | 310ms | 8ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WDDXF257 | 284ms | 238ms | 42ms | 3rd |
| https://rensselaer-polytechnic-institute.contact-server.com/mtc.js | 253ms | 167ms | 1ms | 3rd |
| https://scripts.clarity.ms/0.8.59/clarity.js | 243ms | 212ms | 8ms | 3rd |
| https://www.rpi.edu/sites/default/files/css/css_wvLZFgldgWnuC_1vR5Z621LoI5Un9LDL-6laGbk09s4.css?delta=1&language=en&theme=rpi&include=eJxFiUsSgCAIQC9keiZMUmdIGMCFnb7GTbv3OVkxDdYbqD8YBBSqgjRLRacAxb_EOWRm6tawBJWeMrObf2_bxcNtUyXOQIf5oj5qsGWOd8pg-AJh7Csb | 114ms | 0ms | 0ms | 3rd |
| https://www.rpi.edu/sites/default/files/js/js_eSuyrTxcfusFaXjeggWsR2y0YuNdX4BfMpfK7YKizCI.js?scope=footer&delta=1&language=en&theme=rpi&include=eJxLz89Pz0mNL0lM108HEjrpqHy9xKzEClTBXJ2igkz9pPz8kuKSosQCMC89Jz8pMUe3uKQyJzMvHQBaliBg | 74ms | 56ms | 16ms | 3rd |
| https://www.rpi.edu/core/assets/vendor/jquery/jquery.min.js?v=4.0.0 | 63ms | 46ms | 14ms | 3rd |
DPage Weight InventoryAction42 resources · 2.0 MB · 161 KB savings availableFIX
~161.1 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 42 resources | 2.0 MiB | ||||||
CPage Weight BudgetAction2.0 MB transferred, 42 requestsREVIEW
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
CImage OptimizationAction8 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
CJS BundlesAction13 scripts, 161 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-TTXBMVKEJW&cx=c>m=4e64k0h2 | 169 KB | 68 KB (40%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WDDXF257 | 127 KB | 60 KB (48%) | ✓ | 3rd |
| https://www.rpi.edu/sites/default/files/js/js_eSuyrTxcfusFaXjeggWsR2y0YuNdX4BfMpfK7YKizCI.js?scope=footer&delta=1&language=en&theme=rpi&include=eJxLz89Pz0mNL0lM108HEjrpqHy9xKzEClTBXJ2igkz9pPz8kuKSosQCMC89Jz8pMUe3uKQyJzMvHQBaliBg | 42 KB | 33 KB (79%) | ✓ | 3rd |
| https://alert.rpi.edu/alerts.js?_=1776810881510 | 0 KB | — | ✓ | 3rd |
| https://www.rpi.edu/core/assets/vendor/jquery/jquery.min.js?v=4.0.0 | 32 KB | — | ✓ | 3rd |
| https://www.rpi.edu/modules/contrib/google_tag/js/gtm.js?tduvt5 | 1 KB | — | ✓ | 3rd |
| https://www.rpi.edu/sites/default/files/js/js_DNi57yiLLaas9DLermymPAhNQkAm8dw7Wh_LjN8WlrA.js?scope=header&delta=0&language=en&theme=rpi&include=eJxLz89Pz0mNL0lM108HEjrpqHy9xKzEClTBXJ2igkz9pPz8kuKSosQCMC89Jz8pMUe3uKQyJzMvHQBaliBg | 1 KB | — | ✓ | 3rd |
| https://www.clarity.ms/tag/rxfz2i6zpq?ref=gtm | 1 KB | — | ✓ | 3rd |
| https://www.rpi.edu/modules/contrib/google_tag/js/gtag.js?tduvt5 | 1 KB | — | ✓ | 3rd |
| https://adp.eab.com/js/adp.min.js | 0 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
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 Loading7 fonts (1024 KB)PASS
Web fonts
7
1024 KB total
Render-blocking
0
of 7
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
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- 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 ~452 KB and ~904 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
AHTTP Cachingmax-age=86400 (1 day)PASS
public, max-age=86400
| Directive | Value | Meaning |
|---|---|---|
| public | — | Any cache may store this response |
| max-age | 86400 | Cache for 1 day |
Network Waterfall42 requests over 2281msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.rpi.edu www.rpi.edu | Other | 379ms | 10 KB | — | €4/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 363ms | 169 KB | 40% | €4/mo | Costly |
Unattributable Unattributable | Other | 310ms | 0 KB | — | €3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 284ms | 127 KB | 48% | €3/mo | Costly |
rensselaer-polytechnic-institute.contact-server.com rensselaer-polytechnic-institute.contact-server.com | Other | 253ms | 4 KB | — | €3/mo | Costly |
Microsoft Clarity scripts.clarity.ms | Session Replay | 243ms | 26 KB | — | €3/mo | Costly |
www.rpi.edu www.rpi.edu | Other | 114ms | 181 KB | — | €1/mo | Optional |
www.rpi.edu www.rpi.edu | Other | 74ms | 42 KB | 79% | €1/mo | Optional |
www.rpi.edu www.rpi.edu | Other | 63ms | 32 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- www.rpi.edu adds 379ms and costs ~€4/month
- Google Tag Manager adds 363ms and costs ~€4/month
- Unattributable adds 310ms and costs ~€3/month
- Google Tag Manager adds 284ms and costs ~€3/month
- rensselaer-polytechnic-institute.contact-server.com adds 253ms and costs ~€3/month
- Microsoft Clarity adds 243ms 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.rpi.edu takes 379ms 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 363ms 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 310ms 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 284ms 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
rensselaer-polytechnic-institute.contact-server.com takes 253ms 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
Microsoft Clarity takes 243ms 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
79% of www.rpi.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