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https://www.uottawa.ca

Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
75
GRADE
C
FIX
3
REVIEW
1
PASS
10
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
23
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
100
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
81
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
92
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

2.61 s

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

18.63 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

1.59 s

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.361

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

5.27 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.

21.71 s

Page Load Progression

375 ms
750 ms
1.1 s
1.5 s
1.9 s
2.2 s
2.6 s
3.0 s
Checks
16
10 PASS 1 REVIEW 3 FIX
F
Page Weight Budget
Action
4.6 MB transferred, 106 requests
FIX
4.6 MB transferred, 106 requests
Critical::
Page weighs 8.0 MB (4.6 MB transferred)
Warning::
Images are 3.2 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 3.2 MB
Warning::
JavaScript is 1.1 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.1 MB
Info::
Fonts are 203 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 203 KB
Warning::
106 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 0.97 g CO2 per page load
4.6 MB / 2.4 MB budget
4.6 MB transferred
106 requests
0.97 g CO2 per page load
Images 3.2 MiB 69%
JavaScript 1.1 MiB 24%
Fonts 203.3 KiB 4%
CSS 54.4 KiB 1%
HTML 26.2 KiB 1%
Other 6.7 KiB 0%
Other 5.0 KiB 0%
Other 3.3 KiB 0%
Other 1.9 KiB 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over budget

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

F
JS Execution Cost
Action
5603ms total JS execution
FIX
5603ms total JS execution
Warning::
https://www.uottawa.ca/sites/g/files/bhrskd331/fil...: 772ms CPU time
Warning::
Unattributable: 708ms CPU time
Warning::
https://analytics.tiktok.com/i18n/pixel/static/mai...: 704ms CPU time
Warning::
https://www.uottawa.ca/en: 637ms CPU time
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-WVK...: 543ms CPU time
Warning::
Third-party scripts: 3783ms (68% of total)

Main Thread Breakdown

Script Evaluation 54% Other 15% Script Parsing & Compilation 14% Style & Layout 13%
ScriptTotalScriptingParse/CompileParty
https://www.uottawa.ca/sites/g/files/bhrskd331/files/js/js_RwRTj6aqZvVFwsXo8YH2VV__7Q3-Ju6FJTvoqAXpWZU.js?scope=header&delta=0&language=en&theme=uottawa&include=eJx1kGtuwzAMgy_kzLuRIbuKy0V-wFbbpKevlwFpO2x_KOiTIBLyQvfNepQP-qLV8MWFUhbwKKkKKAd2UZP9b2BiKVHYKUUbh_zuf86-wWQwN0rsGnfcuVlkqNlzfIsR-EZtc52phbN9b4d9nhHdXFoyl6JKN7KBUiXEzO1AMwX2I_BUsbI8MdbdfBwLgXuHh0C317mSRz7x-vn3RpTiSaaumyDHA3coI9VWrvxkgrBMQ08vwXqmGs6kB1AseuS8gm_d7rp_7gFk_6Nb772ms463ms13ms1st
Unattributable708ms129ms0ms3rd
https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwMQ.js704ms384ms254ms3rd
https://www.uottawa.ca/en637ms8ms1ms1st
https://www.googletagmanager.com/gtm.js?id=GTM-WVKZFC543ms442ms84ms3rd
https://www.uottawa.ca/sites/g/files/bhrskd331/files/js/js_f6HUhyIqRKOI6LbMUIhd4AvYW3d-YV_AaD9LZR5k6yY.js?scope=footer&delta=2&language=en&theme=uottawa&include=eJx1kGtuwzAMgy_kzLuRIbuKy0V-wFbbpKevlwFpO2x_KOiTIBLyQvfNepQP-qLV8MWFUhbwKKkKKAd2UZP9b2BiKVHYKUUbh_zuf86-wWQwN0rsGnfcuVlkqNlzfIsR-EZtc52phbN9b4d9nhHdXFoyl6JKN7KBUiXEzO1AMwX2I_BUsbI8MdbdfBwLgXuHh0C317mSRz7x-vn3RpTiSaaumyDHA3coI9VWrvxkgrBMQ08vwXqmGs6kB1AseuS8gm_d7rp_7gFk_6Nb411ms163ms69ms1st
https://www.googletagmanager.com/gtag/js?id=G-GKVJ53FL3H&cx=c&gtm=4e6460402ms320ms54ms3rd
https://www.redditstatic.com/ads/pixel.js402ms367ms8ms3rd
https://connect.facebook.net/en_US/fbevents.js325ms154ms170ms3rd
https://www.googletagmanager.com/gtag/js?id=AW-873072808&cx=c&gtm=4e6460250ms211ms37ms3rd

Showing top 10 of 15 scripts

D
JS Bundles
Action
38 scripts, 363 KB unused
FIX
38 scripts, 363 KB unused
Warning::
https://www.uottawa.ca/sites/g/files/bhrskd331/fil...: 69 KB unused (52%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-GKVJ...: 64 KB unused (36%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-WVK...: 62 KB unused (38%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=AW-873...: 61 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://analytics.tiktok.com/i18n/pixel/static/mai...: 54 KB unused (50%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 363 KB
363 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.uottawa.ca/sites/g/files/bhrskd331/files/js/js_f6HUhyIqRKOI6LbMUIhd4AvYW3d-YV_AaD9LZR5k6yY.js?scope=footer&delta=2&language=en&theme=uottawa&include=eJx1kGtuwzAMgy_kzLuRIbuKy0V-wFbbpKevlwFpO2x_KOiTIBLyQvfNepQP-qLV8MWFUhbwKKkKKAd2UZP9b2BiKVHYKUUbh_zuf86-wWQwN0rsGnfcuVlkqNlzfIsR-EZtc52phbN9b4d9nhHdXFoyl6JKN7KBUiXEzO1AMwX2I_BUsbI8MdbdfBwLgXuHh0C317mSRz7x-vn3RpTiSaaumyDHA3coI9VWrvxkgrBMQ08vwXqmGs6kB1AseuS8gm_d7rp_7gFk_6Nb134 KB69 KB (52%)✓1st
https://www.googletagmanager.com/gtag/js?id=G-GKVJ53FL3H&cx=c&gtm=4e6460178 KB64 KB (36%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-WVKZFC165 KB62 KB (38%)✓3rd
https://www.googletagmanager.com/gtag/js?id=AW-873072808&cx=c&gtm=4e6460146 KB61 KB (42%)✓3rd
https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwMQ.js110 KB54 KB (50%)✓3rd
https://connect.facebook.net/en_US/fbevents.js95 KB32 KB (34%)✓3rd
https://www.uottawa.ca/sites/g/files/bhrskd331/files/js/js_17DkJEeQQi8P3KAkWwSYqfUyECzXDD9xwODiqGixV2o.js?scope=footer&delta=0&language=en&theme=uottawa&include=eJx1kGtuwzAMgy_kzLuRIbuKy0V-wFbbpKevlwFpO2x_KOiTIBLyQvfNepQP-qLV8MWFUhbwKKkKKAd2UZP9b2BiKVHYKUUbh_zuf86-wWQwN0rsGnfcuVlkqNlzfIsR-EZtc52phbN9b4d9nhHdXFoyl6JKN7KBUiXEzO1AMwX2I_BUsbI8MdbdfBwLgXuHh0C317mSRz7x-vn3RpTiSaaumyDHA3coI9VWrvxkgrBMQ08vwXqmGs6kB1AseuS8gm_d7rp_7gFk_6Nb29 KB21 KB (73%)✓1st
https://analytics.tiktok.com/i18n/pixel/events.js?sdkid=C6OG9ERSVD35Q9TRJ990&lib=ttq3 KB—✓3rd
https://www.uottawa.ca/modules/contrib/google_tag/js/gtm.js?tci2ce1 KB—✓1st
https://www.uottawa.ca/themes/custom/uottawa/src/js/lib/tiktok-pixel.js?tci2ce1 KB—✓1st

Consider code splitting or tree shaking to reduce unused code.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

C
Image Optimization
Action
20 images, 0 KB saveable
REVIEW
20 images, 0 KB saveable
Warning::
https://www.uottawa.ca/themes/custom/uottawa/dist/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.uottawa.ca/themes/custom/uottawa/dist/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
20 images 3.2 MB
0 oversized -0 KB
20 legacy format
2 missing dimensions CLS risk

Set explicit width and height to prevent CLS.

Why this matters

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.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

A
Third-Party Impact
24% third-party, 0 ms blocking
PASS
24% third-party, 0 ms blocking
Info::
Third-party code accounts for 24% of page weight (1.1 MiB of 4.6 MiB)
Info::
Third-party blocking time is low (0 ms)
76%
24%
First-party Third-party
A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+
Font Loading
4 fonts (203 KB)
PASS
4 fonts (203 KB)
Info::
4 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

4

203 KB total

Render-blocking

0

of 4

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s 12.0 s 14.0 s 16.0 s 18.0 s FCP 2.6 s LCP 18.6 shttps://fonts.gstatic.com/s/worksans/v24/QGYsz_wNahGAdqQ43Rh_fKDptfpA4Q.woff2QGYsz_wNahGAdqQ43Rh_fKD... https://fonts.gstatic.com/s/worksans/v24/QGYsz_wNahGAdqQ43Rh_fKDptfpA4Q.woff2 — 49.4 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/materialicons/v145/flUhRq6tzZclQEJ-Vdg-IuiaDsNcIhQ8tQ.woff2flUhRq6tzZclQEJ-Vdg-Iui... https://fonts.gstatic.com/s/materialicons/v145/flUhRq6tzZclQEJ-Vdg-IuiaDsNcIhQ8tQ.woff2 — 125.6 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/spectral/v15/rnCr-xNNww_2s0amA9M5knjsS_ul.woff2rnCr-xNNww_2s0amA9M5knj... https://fonts.gstatic.com/s/spectral/v15/rnCr-xNNww_2s0amA9M5knjsS_ul.woff2 — 13.7 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/spectral/v15/rnCs-xNNww_2s0amA9uSsG3BafaPWnII.woff2rnCs-xNNww_2s0amA9uSsG3... https://fonts.gstatic.com/s/spectral/v15/rnCs-xNNww_2s0amA9uSsG3BafaPWnII.woff2 — 14.5 KiB — 0 ms — font-display: swap
QGYsz_wNahGAdqQ43Rh_fKD... woff2 swap
Size 49 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
flUhRq6tzZclQEJ-Vdg-Iui... woff2 swap
Size 126 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
rnCr-xNNww_2s0amA9M5knj... woff2 swap
Size 14 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
rnCs-xNNww_2s0amA9uSsG3... woff2 swap
Size 15 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
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 ~63 KB and ~126 ms

A+
Resource Caching
All resources properly cached
PASS
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
No render-blocking resources detected
A+
Resource Hints
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

A
HTTP Caching
max-age=900 (15 minutes)
PASS
max-age=900 (15 minutes)
Info::
Cache-Control header is set
Got: max-age=900, public
Info::
Effective TTL: 15 minutes (max-age=900)
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

max-age=900, public

DirectiveValueMeaning
max-age900Cache for 15 minutes
public—Any cache may store this response
Effective TTL: 900 seconds
Network Waterfall
106 requests over 0ms
INFO

Performance analysis not available for this result.

Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
68% of JavaScript execution is third-party
First-party Third-party 3783ms · 861KB · CA$52/mo
Unattributable
Other
Costly
Execution 708ms
Transfer 0 KB
Monthly Cost CA$10/mo
analytics.tiktok.com
Other
Costly
Execution 704ms
Transfer 110 KB
Unused 50%
Monthly Cost CA$10/mo
Google Tag Manager
Tag Manager
Costly
Execution 543ms
Transfer 165 KB
Unused 38%
Monthly Cost CA$8/mo
Google Tag Manager
Tag Manager
Costly
Execution 402ms
Transfer 178 KB
Unused 36%
Monthly Cost CA$6/mo
www.redditstatic.com
Other
Costly
Execution 402ms
Transfer 19 KB
Monthly Cost CA$6/mo
Facebook Pixel
Advertising
Costly
Execution 325ms
Transfer 95 KB
Unused 34%
Monthly Cost CA$4/mo
Google Tag Manager
Tag Manager
Costly
Execution 250ms
Transfer 146 KB
Unused 42%
Monthly Cost CA$3/mo
sc-static.net
Other
Optional
Execution 136ms
Transfer 25 KB
Monthly Cost CA$2/mo
Facebook Pixel
Advertising
Optional
Execution 110ms
Transfer 39 KB
Monthly Cost CA$2/mo
siteimproveanalytics.com
Other
Optional
Execution 79ms
Transfer 27 KB
Monthly Cost CA$1/mo
LinkedIn Insight
Advertising
Optional
Execution 72ms
Transfer 19 KB
Monthly Cost CA$1/mo
analytics.tiktok.com
Other
Optional
Execution 52ms
Transfer 40 KB
Monthly Cost CA$1/mo

These scripts may cost more than they're worth

  • Unattributable adds 708ms and costs ~CA$10/month
  • analytics.tiktok.com adds 704ms and costs ~CA$10/month
  • Google Tag Manager adds 543ms and costs ~CA$8/month
  • Google Tag Manager adds 402ms and costs ~CA$6/month
  • www.redditstatic.com adds 402ms and costs ~CA$6/month
  • Facebook Pixel adds 325ms and costs ~CA$4/month
  • Google Tag Manager adds 250ms and costs ~CA$3/month

68% of JavaScript execution time comes from third-party scripts.

Why this matters

Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.

Learn more ▾

Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.

Source: web.dev / HTTP Archive Web Almanac

Unattributable takes 708ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

analytics.tiktok.com takes 704ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

Google Tag Manager takes 543ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

Google Tag Manager takes 402ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

www.redditstatic.com takes 402ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

Facebook Pixel takes 325ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

Google Tag Manager takes 250ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

How third-party costs are calculated

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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