Performance

· 15 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

100

Accessibility

100

Best Practices

100

SEO

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

1.41 s

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

1.55 s

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

21 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.

1.80 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.

2.59 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

6 PASS 4 REVIEW 3 FIX

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 (1.4 MiB of 1.4 MiB)

Third-party blocking time is low (0 ms)

100%

First-party Third-party

Page Weight Inventory

Action

59 resources · 1.4 MB · 291 KB savings available

FIX

59 resources · 1.4 MB · 291 KB savings available

Page weight 377 KB over 1MB target

Got: 1.4 MB Expected: ≤ 1 MB

~291 KB of savings available

58 third-party resources (100% of weight)

2 resources over 200KB

59 resources · 1.4 MiB · 58 third-party 376.6 KiB over 1MB target

JavaScript 60% · 844.2 KiB

Image 25% · 354.7 KiB

CSS 9% · 129.3 KiB

Font 3% · 42.2 KiB

Document 2% · 27.7 KiB

Other 0% · 2.5 KiB

~291.2 KiB of savings available

Remove unused JavaScript: 291.2 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

59 resources			1.4 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.

Page Weight Budget

1.4 MB transferred, 59 requests

REVIEW

1.4 MB transferred, 59 requests

Page weighs 4.1 MB (1.4 MB transferred)

JavaScript is 844 KB — consider code splitting or lazy loading

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

Got: 844 KB

59 HTTP requests

Estimated 0.29 g CO2 per page load

1.4 MB transferred

59 requests

0.29 g CO2 per page load

JavaScript 844.2 KiB 60%

Images 333.0 KiB 24%

CSS 129.3 KiB 9%

Fonts 42.2 KiB 3%

HTML 27.5 KiB 2%

Other 21.9 KiB 2%

Other 1.1 KiB 0%

Other 945 B 0%

Other 548 B 0%

0 2.4 MB 4.9 MB

Under budget

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

Image Optimization

4 images, 0 KB saveable

REVIEW

4 images, 0 KB saveable

https://www.ontario.ca/themes/ontario_2021/assets/... is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

4 images 333 KB

0 oversized -0 KB

4 legacy format

1 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

JS Bundles

Action

39 scripts, 291 KB unused

REVIEW

39 scripts, 291 KB unused

https://www.ontario.ca/libraries/ontario-search-au...: 102 KB unused (40%)