Performance

· 28 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

100

SEO

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

1.62 s

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

3.26 s

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

206 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.

1.88 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.

6.61 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

15 PASS 8 REVIEW 1 FIX

Page Weight Budget

Action

4.0 MB transferred, 35 requests

FIX

4.0 MB transferred, 35 requests

Page weighs 4.9 MB (4.0 MB transferred)

Images are 1.2 MB — compress or use modern formats

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

Got: 1.2 MB

35 HTTP requests

Estimated 0.84 g CO2 per page load

4.0 MB transferred

35 requests

0.84 g CO2 per page load

Other 2.3 MiB 57%

Images 1.2 MiB 30%

JavaScript 337.1 KiB 8%

Other 88.8 KiB 2%

Fonts 74.5 KiB 2%

HTML 17.5 KiB 0%

CSS 15.5 KiB 0%

Other 11.3 KiB 0%

Other 553 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

Image Optimization

8 images, 0 KB saveable

REVIEW

8 images, 0 KB saveable

All images are well-optimized

8 images 1.2 MB

0 oversized -0 KB

8 legacy format

0 missing dimensions CLS risk

JS Execution Cost

Action

1387ms total JS execution

REVIEW

1387ms total JS execution

https://www.googletagmanager.com/gtag/js?id=G-R22L...: 497ms CPU time

Unattributable: 450ms CPU time

https://vitalitydentistry.com/: 340ms CPU time

https://www.googletagmanager.com/gtm.js?id=GTM-N3N...: 100ms CPU time

Third-party scripts: 598ms (43% of total)

Main Thread Breakdown

Script Evaluation 42% Other 31% Style & Layout 13% Script Parsing & Compilation 7% Rendering 3%

Script	Total	Scripting	Parse/Compile	Party
https://www.googletagmanager.com/gtag/js?id=G-R22LR0L6W2	497ms	439ms	53ms	3rd
Unattributable	450ms	27ms	0ms	1st
https://vitalitydentistry.com/	340ms	26ms	5ms	1st
https://www.googletagmanager.com/gtm.js?id=GTM-N3NVVSVB	100ms	65ms	35ms	3rd

JS Bundles

10 scripts, 136 KB unused

REVIEW

10 scripts, 136 KB unused

https://www.googletagmanager.com/gtm.js?id=GTM-N3N...: 75 KB unused (65%)

Consider code splitting or tree shaking to reduce unused code.

https://www.googletagmanager.com/gtag/js?id=G-R22L...: 61 KB unused (31%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 136 KB

136 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://www.googletagmanager.com/gtm.js?id=GTM-N3NVVSVB	116 KB	75 KB (65%)	✓	3rd
https://www.googletagmanager.com/gtag/js?id=G-R22LR0L6W2	196 KB	61 KB (31%)	✓	3rd
https://vitalitydentistry.com/airo-video-slots.js	5 KB	—	✓	1st
https://vitalitydentistry.com/airo-logo-orientation.js	3 KB	—	✓	1st
https://vitalitydentistry.com/analytics.js?v=5	2 KB	—	✓	1st
https://vitalitydentistry.com/floating-cta.js	2 KB	—	✓	1st
https://vitalitydentistry.com/cookie-consent.js?v=2	3 KB	—	✓	1st
https://vitalitydentistry.com/search.js	6 KB	—	✓	1st
https://plausible.io/js/script.js	2 KB	—	✓	3rd
https://googleads.g.doubleclick.net/pagead/viewthroughconversion/18482887555/?random=1794616500217&cv=11&fst=1794616500217&bg=ffffff&guid=ON&async=1&en=gtag.config&gtm=45je6bb1v9265598231za208zd9265598231xecxf1&gcd=13l3l3l3l1l1&dma=0&tag_exp=115616985~115938466~115938468~117628656~117776796~118897920~118897930~120213116~120385423~120412526~120420414~120469145~120469153~121191153~121246026~121246034&u_w=412&u_h=823&url=https%3A%2F%2Fvitalitydentistry.com%2F&ref=https%3A%2F%2Fvitalitydentistry.com%2F&rcb=14&frm=0&tiba=Dentistry%20at%20Vitality%20Health%20%7C%20Markham%20Dentist%20Since%201985&hn=www.googleadservices.com&npa=0&pscdl=noapi&auid=1063091491.1794616500&uaa=&uab=64&uafvl=Not%253AA-Brand%3B8.0.0.0%7CChromium%3B156.0.8078.79&uamb=1&uam=moto%20g%20power%20(2022)&uap=Android&uapv=11.0&uaw=0&data=event%3Dgtag.config&ept=9&rfmt=3&fmt=4	3 KB	—	✓	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

HTTP/3 (QUIC)

HTTP/3 not advertised

REVIEW

HTTP/3 not advertised

HTTP/3 (QUIC) is not advertised

HTTP/3 isn't advertised via Alt-Svc and the worker didn't negotiate h3. HTTP/3 reduces handshake latency (1-RTT instead of 2-3 RTTs) and is more resilient on lossy connections. Most modern CDNs (Cloudflare, Fastly, AWS CloudFront, Google Cloud CDN) support HTTP/3 with a single config switch -- consider enabling for mobile-heavy workloads.

Server-Timing Observability

No Server-Timing header found

REVIEW

No Server-Timing header found

Server-Timing exposes backend timing breakdowns to browser DevTools (e.g., `db: 45ms; render: 120ms; cache: 2ms`). Useful for diagnosing slow pages without backend log access. Most modern frameworks (Next.js, Cloudflare Workers, Fastly) emit it automatically; absence on a managed platform usually means telemetry headers are stripped at the edge.

Page Weight Inventory

Action

35 resources · 4.0 MB · 136 KB savings available

REVIEW

35 resources · 4.0 MB · 136 KB savings available

Page weight 4.0 MB exceeds 1 MB target by 3.0 MB

Got: 4.0 MB Expected: ≤ 1 MB

~136 KB of savings available

11 third-party resources (8% of weight)

4 resources over 200KB

35 resources · 4.0 MiB · 11 third-party 3.0 MiB over 1MB target

Media 57% · 2.3 MiB

Image 32% · 1.3 MiB

JavaScript 8% · 337.1 KiB

Font 2% · 74.5 KiB

Document 0% · 17.7 KiB

CSS 0% · 15.5 KiB

Other 0% · 11.8 KiB

~136.1 KiB of savings available

Remove unused JavaScript: 136.1 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

35 resources			4.0 MiB

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

HTTP Caching

public, max-age=0, must-revalidate

REVIEW

public, max-age=0, must-revalidate

Cache-Control header is set

Got: public, max-age=0, must-revalidate

Last-Modified header present

Cache-Control

public, max-age=0, must-revalidate

Directive	Value	Meaning
public	—	Any cache may store this response
max-age	0	Cache for 0 seconds
must-revalidate	—	Must recheck with server after expiry

A+

Third-Party Impact

8% third-party, 0 ms blocking

PASS

8% third-party, 0 ms blocking

Third-party code accounts for 8% of page weight (318.6 KiB of 4.0 MiB)

Third-party blocking time is low (0 ms)

92%

First-party Third-party

A+

Text Compression

All text resources are compressed

PASS

All text resources are compressed

All text resources are properly compressed.

A+

Font Loading

2 fonts (74 KB)

PASS

2 fonts (74 KB)

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

Web fonts

74 KB total

Render-blocking

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

dm-sans-latin.woff2 woff2 swap

Size 37 KB

Load time 350 ms

Start 1.8 s

Risk FOUT — text flashes from fallback to web font

cormorant-garamond-lati... woff2 swap

Size 38 KB

Load time 452 ms

Start 1.8 s

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)

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

3 hints, 0 missing preconnects

PASS

3 hints, 0 missing preconnects

Page uses 3 resource hint(s)

Current Resource Hints

preconnect

—

preload

dns-prefetch

—

prefetch

—

3 resource hints configured

A+

Document Compression

Document response uses brotli

PASS

Document response uses brotli

Main HTML response uses brotli (Content-Encoding: br)

Brotli is the best text-compression algorithm for general use, ~20% smaller than gzip on average (40% on smaller files). Modern browsers all support it.

Asset Compression

1 of 1 asset host still on gzip

PASS

1 of 1 asset host still on gzip

www.googletagmanager.com serves assets with gzip; brotli would be ~20% smaller (assets: 3)

Every current browser accepts brotli. On a CDN this is a per-pull-zone toggle (Cloudflare, Fastly, CloudFront, CDN77, Bunny all expose it); on an origin it needs the brotli module (nginx-brotli, Apache mod_brotli). The saving lands on the assets this host serves, not on the HTML document -- the document's own encoding is reported separately.

Got: www.googletagmanager.com (application/javascript)

A+

LCP Image Preload

LCP preload audit not available

PASS

LCP preload audit not available

LCP image preload audit not available for this scan

A+

Main HTML Cache-Control

Main HTML max-age=0 (≤ 5min) is appropriate

PASS

Main HTML max-age=0 (≤ 5min) is appropriate

Got: public, max-age=0, must-revalidate

A+

Server Response Intelligence

2 server-response signal(s) detected

PASS

2 server-response signal(s) detected

`Vary` header declared: Accept-Encoding

The page declares a `Vary` header, telling downstream caches which request headers the response varies on. Critical for content-negotiated responses (compression, language, cookies, device class).

`Last-Modified` present -- timestamp-based conditional GET supported

Consider also setting `ETag` for stronger revalidation -- ETags are content hashes that don't suffer from clock-skew or DST issues. Last-Modified alone is functional for conditional GETs and not a bug.

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

JavaScript Blocking

1 JS blocking issue(s) detected

PASS

1 JS blocking issue(s) detected

3 render-blocking <script src> tag(s) without async/defer

Each `<script src=...>` without `async`, `defer`, or `type="module"` blocks HTML parsing while the browser fetches and executes it. The block lasts the entire round-trip + execution time -- on slow networks this translates directly into LCP delay. Add `defer` (executes after parse, in source order) for scripts that interact with the DOM, or `async` (executes whenever ready) for analytics / independent scripts. Module scripts (`type="module"`) are deferred by default.

A+

CSS Performance Depth

No CSS performance depth issues detected

PASS

No CSS performance depth issues detected

Network Waterfall

35 requests over 2970ms

INFO

HTML JavaScript CSS Images Fonts XHR/Fetch Other

Third-Party Script Cost

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

INFO

43% of JavaScript execution is third-party

First-party Third-party 598ms · 312KB · $8/mo

Script	Category	Execution	Transfer	Unused	Monthly Cost	Verdict
Google Tag Manager www.googletagmanager.com	Tag Manager	497ms	196 KB	31%	$7/mo	Costly
Google Tag Manager www.googletagmanager.com	Tag Manager	100ms	116 KB	65%	$1/mo	Optional

Google Tag Manager

Tag Manager

Costly

Execution 497ms

Transfer 196 KB

Unused 31%

Monthly Cost $7/mo

Google Tag Manager

Tag Manager

Optional

Execution 100ms

Transfer 116 KB

Unused 65%

Monthly Cost $1/mo

These scripts may cost more than they're worth

Google Tag Manager adds 497ms and costs ~$7/month

43% 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

Google Tag Manager takes 497ms 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

65% of Google Tag Manager'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

Real-User Performance (CrUX)

Field metrics from the Chrome User Experience Report

INFO

Chrome User Experience (CrUX)

Real-user metrics from the Chrome UX Report (2026-10-15 — 2026-11-11)

LCP (p75)

890 ms

98% good

INP (p75)

0 ms

0% good

CLS (p75)

0.000

98% good

FCP (p75)

814 ms

TTFB (p75)

367 ms

Image Optimization

7 images, 1078 KB total, 1008 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

1078 KB

Oversized

Wasted

1008 KB

1 missing lazy loading

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