Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

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

Mobile Desktop

Performance

Accessibility

Best Practices

SEO

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

4.43 s

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

10.36 s

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

1.31 s

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

0.971

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

13.94 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.

34.50 s

Page Load Progression

441 ms

883 ms

1.3 s

1.8 s

2.2 s

2.6 s

3.1 s

3.5 s

Checks

8 PASS 1 REVIEW 6 FIX

Page Weight Budget

Action

5.2 MB transferred, 154 requests

FIX

5.2 MB transferred, 154 requests

Page weighs 10.1 MB (5.2 MB transferred)

Images are 2.9 MB — compress or use modern formats

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

Got: 2.9 MB

JavaScript is 1.9 MB — consider code splitting or lazy loading

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Got: 1.9 MB

Fonts are 341 KB — consider subsetting or using system fonts

Subset fonts to include only used characters, or switch to system font stacks.

Got: 341 KB

154 HTTP requests — consider bundling or reducing

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Estimated 1.1 g CO2 per page load

5.2 MB transferred

154 requests

1.1 g CO2 per page load

Images 2.9 MiB 56%

JavaScript 1.9 MiB 36%

Fonts 341.0 KiB 6%

HTML 35.7 KiB 1%

CSS 35.3 KiB 1%

Other 7.5 KiB 0%

Other 6.0 KiB 0%

Other 4.0 KiB 0%

Other 1.4 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

Third-Party Impact

Action

100% third-party, 0 ms blocking

FIX

100% third-party, 0 ms blocking

Third-party code accounts for 100% of page weight (5.2 MiB of 5.2 MiB)

Third-party blocking time is low (0 ms)

100%

First-party Third-party

JS Execution Cost

Action

7536ms total JS execution

FIX

7536ms total JS execution

https://www.uwa.edu.au/home: 2050ms CPU time

Unattributable: 825ms CPU time

https://www.uwa.edu.au/_next/static/chunks/862.c3b...: 816ms CPU time

https://www.googletagmanager.com/gtm.js?id=GTM-N39...: 665ms CPU time

https://www.googletagmanager.com/gtag/js?id=G-FQKY...: 438ms CPU time

Third-party scripts: 7536ms (100% of total)

Main Thread Breakdown

Script Evaluation 52% Other 19% Rendering 11% Style & Layout 8% Script Parsing & Compilation 6%

Script	Total	Scripting	Parse/Compile	Party
https://www.uwa.edu.au/home	2050ms	9ms	5ms	3rd
Unattributable	825ms	83ms	0ms	3rd
https://www.uwa.edu.au/_next/static/chunks/862.c3bf0b1c834f59ed.js?dpl=dpl_7tBuqLGahnT6xxbYrGJGUgMhQR5f	816ms	619ms	0ms	3rd
https://www.googletagmanager.com/gtm.js?id=GTM-N397MQR	665ms	587ms	58ms	3rd
https://www.googletagmanager.com/gtag/js?id=G-FQKYCDD16S&cx=c&gtm=4e64h1	438ms	265ms	34ms	3rd
https://www.uwa.edu.au/_next/static/chunks/framework-de98b93a850cfc71.js?dpl=dpl_7tBuqLGahnT6xxbYrGJGUgMhQR5f	329ms	284ms	13ms	3rd
https://www.googletagmanager.com/gtag/js?id=AW-10979345866&cx=c&gtm=4e64h1	290ms	258ms	30ms	3rd
https://www.googletagmanager.com/gtag/js?id=G-3TZVGFFX6H&cx=c&gtm=4e64h1	258ms	214ms	40ms	3rd
https://www.googletagmanager.com/gtag/js?id=G-886292W0J6&cx=c&gtm=4e64h1	235ms	194ms	38ms	3rd
https://scripts.clarity.ms/0.8.60-beta/clarity.js	230ms	204ms	7ms	3rd

Showing top 10 of 20 scripts

JS Bundles

Action

41 scripts, 710 KB unused

FIX

41 scripts, 710 KB unused

https://www.uwa.edu.au/_next/static/chunks/905-592...: 91 KB unused (70%)

Consider code splitting or tree shaking to reduce unused code.

https://www.googletagmanager.com/gtag/js?id=G-8862...: 71 KB unused (41%)

Consider code splitting or tree shaking to reduce unused code.

https://www.googletagmanager.com/gtag/js?id=G-3TZV...: 67 KB unused (39%)

Consider code splitting or tree shaking to reduce unused code.

https://www.googletagmanager.com/gtag/js?id=G-84TW...: 67 KB unused (42%)

Consider code splitting or tree shaking to reduce unused code.

https://www.googletagmanager.com/gtag/js?id=G-FQKY...: 64 KB unused (41%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 710 KB

710 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://www.uwa.edu.au/_next/static/chunks/905-592e6859982e2f85.js?dpl=dpl_7tBuqLGahnT6xxbYrGJGUgMhQR5f	131 KB	91 KB (70%)	✓	3rd
https://www.googletagmanager.com/gtag/js?id=G-886292W0J6&cx=c&gtm=4e64h1	174 KB	71 KB (41%)	✓	3rd
https://www.googletagmanager.com/gtag/js?id=G-3TZVGFFX6H&cx=c&gtm=4e64h1	172 KB	67 KB (39%)	✓	3rd
https://www.googletagmanager.com/gtag/js?id=G-84TWJYTGPY&cx=c&gtm=4e64h1	157 KB	67 KB (42%)	✓	3rd
https://www.googletagmanager.com/gtag/js?id=G-FQKYCDD16S&cx=c&gtm=4e64h1	157 KB	64 KB (41%)	✓	3rd
https://www.googletagmanager.com/gtag/js?id=AW-10979345866&cx=c&gtm=4e64h1	145 KB	62 KB (43%)	✓	3rd
https://www.googletagmanager.com/gtag/js?id=DC-9815668&cx=c&gtm=4e64h1	129 KB	57 KB (44%)	✓	3rd
https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwMQ.js	110 KB	56 KB (51%)	✓	3rd
https://www.googletagmanager.com/gtm.js?id=GTM-N397MQR	199 KB	52 KB (26%)	✓	3rd
https://connect.facebook.net/en_US/fbevents.js	97 KB	34 KB (36%)	✓	3rd

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

Page Weight Inventory

Action

154 resources · 5.2 MB · 710 KB savings available

FIX

154 resources · 5.2 MB · 710 KB savings available

Page weight 4.2 MB over 1MB target

Got: 5.2 MB Expected: ≤ 1 MB

~710 KB of savings available

153 third-party resources (100% of weight)

5 resources over 200KB

154 resources · 5.2 MiB · 153 third-party 4.2 MiB over 1MB target

Image 56% · 2.9 MiB

JavaScript 36% · 1.9 MiB

Font 6% · 341.0 KiB

Document 1% · 39.5 KiB

CSS 1% · 35.3 KiB

Other 0% · 12.0 KiB

~710.0 KiB of savings available

Remove unused JavaScript: 710.0 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

154 resources			5.2 MiB

HTTP Caching

Action

No cache headers

FIX

No cache headers

No Cache-Control header found

Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.

No Cache-Control header

Adding a Cache-Control header can significantly improve repeat-visit performance.

Image Optimization

Action

51 images, 0 KB saveable

REVIEW

51 images, 0 KB saveable

https://static.weboffice.uwa.edu.au/visualid/devco... is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

https://static.weboffice.uwa.edu.au/visualid/devco... is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

51 images 2.9 MB

0 oversized -0 KB

51 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+

Text Compression

All text resources are compressed

PASS

All text resources are compressed

All text resources are properly compressed.

A+

Font Loading

5 fonts (341 KB)

PASS

5 fonts (341 KB)

5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

341 KB total

Render-blocking

of 5

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

3AB790_2_0.b116682e.woff2 woff2 swap

Size 57 KB

Load time 38 ms

Start 2.0 s

Risk FOUT — text flashes from fallback to web font

MelunDisplayUWA-Bold.a6... woff2 swap

Size 45 KB

Load time 45 ms

Start 2.0 s

Risk FOUT — text flashes from fallback to web font

3AB790_E_0.8334a331.woff2 woff2 swap

Size 55 KB

Load time 40 ms

Start 2.0 s

Risk FOUT — text flashes from fallback to web font

PlusJakartaSans-Variabl... ttf swap

Size 77 KB

Load time 35 ms

Start 2.3 s

Risk FOUT — text flashes from fallback to web font

Convert to woff2 for ~30% smaller file size

Petrona-VariableFont_wg... ttf swap

Size 107 KB

Load time 40 ms

Start 2.3 s

Risk FOUT — text flashes from fallback to web font

Convert to woff2 for ~30% smaller file size
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 ~108 KB and ~216 ms

A+

Resource Caching

All resources properly cached

PASS

All resources properly cached

No caching issues found

All static resources have appropriate caching headers.

A+

Critical Rendering Path

No render-blocking resources

PASS

No render-blocking resources

No render-blocking resources detected

A+

Resource Hints

29 hints, 0 missing preconnects

PASS

29 hints, 0 missing preconnects

Page uses 29 resource hint(s)

Current Resource Hints

preconnect

preload

+18

dns-prefetch

—

prefetch

—

29 resource hints configured

A+

Render-Blocking Resources

No render-blocking resources detected

PASS

No render-blocking resources detected

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

Network Waterfall

154 requests over 7493ms

INFO

HTML JavaScript CSS Images Fonts XHR/Fetch Other

Third-Party Script Cost

Per-script blocking time, transfer cost, and cache headers

INFO

100% of JavaScript execution is third-party

First-party Third-party 7536ms · 1707KB · A$130/mo

Script	Category	Execution	Transfer	Unused	Monthly Cost	Verdict
www.uwa.edu.au www.uwa.edu.au	Other	2050ms	32 KB	—	A$35/mo	Costly
Unattributable Unattributable	Other	825ms	0 KB	—	A$14/mo	Costly
www.uwa.edu.au www.uwa.edu.au	Other	816ms	0 KB	—	A$14/mo	Costly
Google Tag Manager www.googletagmanager.com	Tag Manager	665ms	199 KB	26%	A$11/mo	Costly
Google Tag Manager www.googletagmanager.com	Tag Manager	438ms	157 KB	41%	A$8/mo	Costly
www.uwa.edu.au www.uwa.edu.au	Other	329ms	60 KB	34%	A$6/mo	Costly
Google Tag Manager www.googletagmanager.com	Tag Manager	290ms	145 KB	43%	A$5/mo	Costly
Google Tag Manager www.googletagmanager.com	Tag Manager	258ms	172 KB	39%	A$4/mo	Costly
Google Tag Manager www.googletagmanager.com	Tag Manager	235ms	174 KB	41%	A$4/mo	Costly
Microsoft Clarity scripts.clarity.ms	Session Replay	230ms	25 KB	—	A$4/mo	Costly
analytics.tiktok.com analytics.tiktok.com	Other	222ms	110 KB	51%	A$4/mo	Costly
Google Tag Manager www.googletagmanager.com	Tag Manager	214ms	157 KB	42%	A$4/mo	Costly
Google Tag Manager www.googletagmanager.com	Tag Manager	194ms	129 KB	44%	A$3/mo	Optional
www.uwa.edu.au www.uwa.edu.au	Other	181ms	1 KB	—	A$3/mo	Optional
Facebook Pixel connect.facebook.net	Advertising	148ms	45 KB	—	A$3/mo	Optional
Facebook Pixel connect.facebook.net	Advertising	126ms	97 KB	36%	A$2/mo	Optional
sc-static.net sc-static.net	Other	116ms	25 KB	—	A$2/mo	Optional
www.uwa.edu.au www.uwa.edu.au	Other	93ms	41 KB	—	A$2/mo	Optional
d1mj578wat5n4o.cloudfront.net d1mj578wat5n4o.cloudfront.net	Other	54ms	7 KB	—	A$1/mo	Optional
www.uwa.edu.au www.uwa.edu.au	Other	53ms	131 KB	70%	A$1/mo	Optional

www.uwa.edu.au

Other

Costly

Execution 2050ms

Transfer 32 KB

Monthly Cost A$35/mo

Unattributable

Other

Costly

Execution 825ms

Transfer 0 KB

Monthly Cost A$14/mo

www.uwa.edu.au

Other

Costly

Execution 816ms

Transfer 0 KB

Monthly Cost A$14/mo

Google Tag Manager

Tag Manager

Costly

Execution 665ms

Transfer 199 KB

Unused 26%

Monthly Cost A$11/mo

Google Tag Manager

Tag Manager

Costly

Execution 438ms

Transfer 157 KB

Unused 41%

Monthly Cost A$8/mo

www.uwa.edu.au

Other

Costly

Execution 329ms

Transfer 60 KB

Unused 34%

Monthly Cost A$6/mo

Google Tag Manager

Tag Manager

Costly

Execution 290ms

Transfer 145 KB

Unused 43%

Monthly Cost A$5/mo

Google Tag Manager

Tag Manager

Costly

Execution 258ms

Transfer 172 KB

Unused 39%

Monthly Cost A$4/mo

Google Tag Manager

Tag Manager

Costly

Execution 235ms

Transfer 174 KB

Unused 41%

Monthly Cost A$4/mo

Microsoft Clarity

Session Replay

Costly

Execution 230ms

Transfer 25 KB

Monthly Cost A$4/mo

analytics.tiktok.com

Other

Costly

Execution 222ms

Transfer 110 KB

Unused 51%

Monthly Cost A$4/mo

Google Tag Manager

Tag Manager

Costly

Execution 214ms

Transfer 157 KB

Unused 42%

Monthly Cost A$4/mo

Google Tag Manager

Tag Manager

Optional

Execution 194ms

Transfer 129 KB

Unused 44%

Monthly Cost A$3/mo

www.uwa.edu.au

Other

Optional

Execution 181ms

Transfer 1 KB

Monthly Cost A$3/mo

Facebook Pixel

Advertising

Optional

Execution 148ms

Transfer 45 KB

Monthly Cost A$3/mo

Facebook Pixel

Advertising

Optional

Execution 126ms

Transfer 97 KB

Unused 36%

Monthly Cost A$2/mo

sc-static.net

Other

Optional

Execution 116ms

Transfer 25 KB

Monthly Cost A$2/mo

www.uwa.edu.au

Other

Optional

Execution 93ms

Transfer 41 KB

Monthly Cost A$2/mo

d1mj578wat5n4o.cloudfront.net

Other

Optional

Execution 54ms

Transfer 7 KB

Monthly Cost A$1/mo

www.uwa.edu.au

Other

Optional

Execution 53ms

Transfer 131 KB

Unused 70%

Monthly Cost A$1/mo

These scripts may cost more than they're worth

www.uwa.edu.au adds 2050ms and costs ~A$35/month
Unattributable adds 825ms and costs ~A$14/month
www.uwa.edu.au adds 816ms and costs ~A$14/month
Google Tag Manager adds 665ms and costs ~A$11/month
Google Tag Manager adds 438ms and costs ~A$8/month
www.uwa.edu.au adds 329ms and costs ~A$6/month
Google Tag Manager adds 290ms and costs ~A$5/month
Google Tag Manager adds 258ms and costs ~A$4/month
Google Tag Manager adds 235ms and costs ~A$4/month
Microsoft Clarity adds 230ms and costs ~A$4/month
analytics.tiktok.com adds 222ms and costs ~A$4/month
Google Tag Manager adds 214ms and costs ~A$4/month

100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.

Why this matters

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.uwa.edu.au takes 2050ms 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

Unattributable takes 825ms 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.uwa.edu.au takes 816ms 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 665ms 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 438ms 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.uwa.edu.au takes 329ms 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 290ms 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 258ms 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 235ms 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

Microsoft Clarity takes 230ms 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 222ms 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

51% of analytics.tiktok.com's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

Google Tag Manager takes 214ms 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

70% of www.uwa.edu.au's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

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.