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.
4.39 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
7.08 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
1.43 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.
5.97 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.
20.43 s
Page Load Progression
DPage Weight BudgetAction2.4 MB transferred, 78 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
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction3691ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 541ms | 80ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-SWMRZYHD0P&cx=c>m=4e64k0 | 404ms | 334ms | 45ms | 3rd |
| https://www.uoguelph.ca/ | 369ms | 16ms | 9ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-NRSSDKW | 331ms | 265ms | 53ms | 3rd |
| https://scripts.clarity.ms/0.8.59/clarity.js | 327ms | 276ms | 6ms | 3rd |
| https://connect.facebook.net/signals/config/2041675079654380?v=2.9.303&r=stable&domain=www.uoguelph.ca&hme=97937018cefade17726f0472876fc101316b2ce9008a35a6a5a7977d7436151a&ex_m=104%2C205%2C154%2C22%2C72%2C73%2C145%2C68%2C67%2C11%2C162%2C90%2C16%2C138%2C127%2C39%2C75%2C78%2C134%2C159%2C164%2C8%2C4%2C5%2C7%2C6%2C3%2C91%2C101%2C165%2C170%2C219%2C62%2C186%2C187%2C55%2C276%2C30%2C74%2C231%2C230%2C229%2C23%2C33%2C103%2C61%2C10%2C63%2C97%2C98%2C99%2C105%2C130%2C31%2C29%2C132%2C133%2C129%2C128%2C155%2C76%2C158%2C156%2C157%2C50%2C60%2C123%2C15%2C161%2C45%2C263%2C264%2C262%2C26%2C27%2C28%2C48%2C146%2C77%2C112%2C18%2C20%2C44%2C40%2C42%2C41%2C83%2C92%2C96%2C110%2C144%2C147%2C46%2C111%2C24%2C21%2C119%2C69%2C36%2C149%2C148%2C150%2C141%2C139%2C25%2C35%2C59%2C109%2C160%2C70%2C17%2C152%2C114%2C81%2C66%2C19%2C85%2C86%2C116%2C84%2C136%2C135%2C34%2C278%2C293%2C212%2C201%2C202%2C200%2C296%2C288%2C52%2C213%2C107%2C131%2C80%2C121%2C54%2C47%2C49%2C113%2C120%2C126%2C58%2C64%2C151%2C115%2C37%2C32%2C53%2C56%2C100%2C163%2C1%2C124%2C14%2C122%2C12%2C2%2C57%2C93%2C65%2C118%2C89%2C88%2C166%2C167%2C94%2C95%2C9%2C125%2C102%2C51%2C142%2C87%2C79%2C71%2C117%2C106%2C43%2C143%2C0%2C82%2C137%2C140%2C153%2C38%2C108%2C13%2C168%2C228%2C227%2C222%2C224%2C225%2C226%2C223%2C211%2C221%2C193%2C190%2C191%2C185%2C189%2C192%2C188%2C183%2C316%2C196%2C215%2C184%2C182%2C235%2C206%2C176%2C177%2C172%2C178%2C175%2C173%2C174%2C171%2C169%2C180%2C181%2C179%2C265%2C315%2C194%2C238%2C239%2C244%2C241%2C243%2C242%2C240%2C237%2C252%2C248%2C249%2C247%2C253%2C250%2C246%2C251%2C245%2C233%2C210 | 250ms | 207ms | 24ms | 3rd |
| https://www.uoguelph.ca/_next-home/_next/static/chunks/794-c55d2d695fbb2f2e.js | 233ms | 207ms | 17ms | 3rd |
| https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwOQ.js | 228ms | 186ms | 39ms | 3rd |
| https://www.uoguelph.ca/_next-home/_next/static/chunks/4bd1b696-096d35a2bd1da3af.js | 221ms | 199ms | 16ms | 3rd |
| https://www.uoguelph.ca/@uoguelph/web-components/index-BCH9nwsS.js | 163ms | 138ms | 1ms | 3rd |
Showing top 10 of 16 scripts
FJS BundlesAction35 scripts, 706 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.uoguelph.ca/_next-home/_next/static/chunks/794-c55d2d695fbb2f2e.js | 184 KB | 80 KB (44%) | ✓ | 3rd |
| https://www.uoguelph.ca/@uoguelph/web-components/index-BCH9nwsS.js | 257 KB | 80 KB (31%) | ✗ | 3rd |
| https://www.uoguelph.ca/_next-home/_next/static/chunks/4bd1b696-096d35a2bd1da3af.js | 194 KB | 79 KB (41%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-NRSSDKW | 174 KB | 78 KB (45%) | ✓ | 3rd |
| https://www.uoguelph.ca/_next-home/_next/static/chunks/275-84474f266077c482.js | 117 KB | 73 KB (62%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-SWMRZYHD0P&cx=c>m=4e64k0 | 179 KB | 66 KB (37%) | ✓ | 3rd |
| https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwOQ.js | 122 KB | 62 KB (52%) | ✓ | 3rd |
| https://www.uoguelph.ca/_next-home/_next/static/chunks/726-f3b3e74c80caa220.js | 80 KB | 43 KB (54%) | ✓ | 3rd |
| https://script.hotjar.com/modules.6a0f3932cb1341a35c18.js | 57 KB | 37 KB (65%) | ✓ | 3rd |
| https://connect.facebook.net/en_US/fbevents.js | 97 KB | 31 KB (32%) | ✓ | 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 InventoryAction78 resources · 2.4 MB · 706 KB savings availableFIX
~705.9 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 78 resources | 2.4 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization17 images, 0 KB saveableREVIEW
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 (70 KB)PASS
Web fonts
2
70 KB total
Render-blocking
0
of 2
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 Hints7 hints, 0 missing preconnectsPASS
Current Resource Hints
7 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall78 requests over 5469msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 541ms | 0 KB | — | CA$7/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 404ms | 179 KB | 37% | CA$6/mo | Costly |
www.uoguelph.ca www.uoguelph.ca | Other | 369ms | 70 KB | — | CA$5/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 331ms | 174 KB | 45% | CA$5/mo | Costly |
Microsoft Clarity scripts.clarity.ms | Session Replay | 327ms | 26 KB | — | CA$5/mo | Costly |
Facebook Pixel connect.facebook.net | Advertising | 250ms | 97 KB | 27% | CA$3/mo | Costly |
www.uoguelph.ca www.uoguelph.ca | Other | 233ms | 184 KB | 44% | CA$3/mo | Costly |
analytics.tiktok.com analytics.tiktok.com | Other | 228ms | 122 KB | 52% | CA$3/mo | Costly |
www.uoguelph.ca www.uoguelph.ca | Other | 221ms | 194 KB | 41% | CA$3/mo | Costly |
www.uoguelph.ca www.uoguelph.ca | Other | 163ms | 257 KB | 31% | CA$2/mo | Optional |
Hotjar script.hotjar.com | Session Replay | 142ms | 57 KB | 65% | CA$2/mo | Optional |
Facebook Pixel connect.facebook.net | Advertising | 135ms | 97 KB | 32% | CA$2/mo | Optional |
kit.fontawesome.com kit.fontawesome.com | Other | 116ms | 6 KB | — | CA$2/mo | Optional |
Facebook Pixel connect.facebook.net | Advertising | 115ms | 45 KB | — | CA$2/mo | Optional |
Facebook Pixel connect.facebook.net | Advertising | 65ms | 19 KB | — | CA$1/mo | Optional |
LinkedIn Insight snap.licdn.com | Advertising | 51ms | 19 KB | — | CA$1/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 541ms and costs ~CA$7/month
- Google Tag Manager adds 404ms and costs ~CA$6/month
- www.uoguelph.ca adds 369ms and costs ~CA$5/month
- Google Tag Manager adds 331ms and costs ~CA$5/month
- Microsoft Clarity adds 327ms and costs ~CA$5/month
- Facebook Pixel adds 250ms and costs ~CA$3/month
- www.uoguelph.ca adds 233ms and costs ~CA$3/month
- analytics.tiktok.com adds 228ms and costs ~CA$3/month
- www.uoguelph.ca adds 221ms and costs ~CA$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
Unattributable takes 541ms 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 404ms 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.uoguelph.ca takes 369ms 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 331ms 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 327ms 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
Facebook Pixel takes 250ms 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.uoguelph.ca takes 233ms 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
analytics.tiktok.com takes 228ms 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
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
www.uoguelph.ca takes 221ms 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
65% 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