Performance

· 27 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

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.

10.23 s

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

13.01 s

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

1.11 s

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

0.032

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

13.37 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.

26.76 s

Page Load Progression

692 ms

1.4 s

2.1 s

2.8 s

3.5 s

4.2 s

4.8 s

5.5 s

Checks

11 PASS 7 REVIEW 6 FIX

Page Weight Budget

Action

6.3 MB transferred, 318 requests

FIX

6.3 MB transferred, 318 requests

Page weighs 15.5 MB (6.3 MB transferred)

JavaScript is 2.2 MB — consider code splitting or lazy loading

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

Got: 2.2 MB

Images are 1.3 MB — compress or use modern formats

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

Got: 1.3 MB

Fonts are 830 KB — consider subsetting or using system fonts

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

Got: 830 KB

CSS is 349 KB — consider purging unused styles

Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.

Got: 349 KB

318 HTTP requests — consider bundling or reducing

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

Estimated 1.3 g CO2 per page load

6.3 MB transferred

318 requests

1.3 g CO2 per page load

JavaScript 2.2 MiB 35%

Other 1.5 MiB 23%

Images 1.3 MiB 21%

Fonts 830.1 KiB 13%

CSS 349.5 KiB 5%

HTML 128.0 KiB 2%

Other 1.5 KiB 0%

Other 1.0 KiB 0%

Other 549 B 0%

Other 0 B 0%

0 2.4 MB 4.9 MB

Over 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

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

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

Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.

Why this matters

CSS bundle is large — purge unused styles (PurgeCSS, Tailwind JIT) to reduce CSS payload.

Source: web.dev

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

72% third-party, 0 ms blocking

FIX

72% third-party, 0 ms blocking

Third-party code accounts for 72% of page weight (4.6 MiB of 6.3 MiB)

Third-party blocking time is low (0 ms)

28%

72%

First-party Third-party

JS Execution Cost

Action

7011ms total JS execution

FIX

7011ms total JS execution

https://biermetstijl.com/: 1553ms CPU time

Unattributable: 1246ms CPU time

https://www.googletagmanager.com/gtag/js?id=G-776T...: 929ms CPU time

https://c0.wp.com/c/7.1.3/wp-includes/js/jquery/jq...: 643ms CPU time

https://biermetstijl.com/wp-content/plugins/age-ga...: 635ms CPU time

Third-party scripts: 1879ms (27% of total)

Main Thread Breakdown

Script Evaluation 39% Other 25% Style & Layout 23% Script Parsing & Compilation 7% Parse HTML & CSS 5%

Script	Total	Scripting	Parse/Compile	Party
https://biermetstijl.com/	1553ms	56ms	41ms	1st
Unattributable	1246ms	54ms	0ms	1st
https://www.googletagmanager.com/gtag/js?id=G-776THC0VQ0	929ms	756ms	73ms	3rd
https://c0.wp.com/c/7.1.3/wp-includes/js/jquery/jquery.min.js	643ms	577ms	9ms	3rd
https://biermetstijl.com/wp-content/plugins/age-gate/dist/all.js?ver=3.7.3	635ms	14ms	1ms	1st
https://biermetstijl.com/wp-content/plugins/jet-elements/assets/js/lib/tweenjs/tweenjs.min.js?ver=2.0.2	439ms	132ms	28ms	1st
https://biermetstijl.com/wp-content/plugins/jupiterx-core/includes/extensions/raven/assets/js/frontend.min.js?ver=7.1.3	379ms	197ms	182ms	1st
https://www.youtube.com/s/player/55de7e60/www-widgetapi.vflset/www-widgetapi.js	250ms	227ms	3ms	3rd
https://biermetstijl.com/wp-content/themes/jupiterx/lib/admin/assets/lib/webfont/webfont.min.js?ver=1.6.26	166ms	149ms	6ms	1st
https://biermetstijl.com/wp-content/plugins/elementor/assets/js/chunks/background-video.min.js?ver=4.3.5	160ms	140ms	4ms	1st

Showing top 10 of 18 scripts

JS Bundles

Action

74 scripts, 305 KB unused

FIX

74 scripts, 305 KB unused

https://biermetstijl.com/wp-content/plugins/jupite...: 150 KB unused (85%)

Consider code splitting or tree shaking to reduce unused code.

https://www.googletagmanager.com/gtag/js?id=G-776T...: 76 KB unused (39%)

Consider code splitting or tree shaking to reduce unused code.

https://biermetstijl.com/wp-content/themes/jupiter...: 30 KB unused (82%)

Consider code splitting or tree shaking to reduce unused code.

https://biermetstijl.com/wp-content/plugins/jet-el...: 28 KB unused (77%)

Consider code splitting or tree shaking to reduce unused code.

https://biermetstijl.com/wp-content/plugins/sellki...: 22 KB unused (91%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 305 KB

305 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://biermetstijl.com/wp-content/plugins/jupiterx-core/includes/extensions/raven/assets/js/frontend.min.js?ver=7.1.3	176 KB	150 KB (85%)	✓	1st
https://www.googletagmanager.com/gtag/js?id=G-776THC0VQ0	194 KB	76 KB (39%)	✓	3rd
https://biermetstijl.com/wp-content/themes/jupiterx/lib/assets/dist/js/frontend.min.js?ver=4.62.0	37 KB	30 KB (82%)	✓	1st
https://biermetstijl.com/wp-content/plugins/jet-elements/assets/js/lib/tweenjs/tweenjs.min.js?ver=2.0.2	36 KB	28 KB (77%)	✓	1st
https://biermetstijl.com/wp-content/plugins/sellkit/assets/dist/js/elementor-init.min.js?ver=2.8.0	24 KB	22 KB (91%)	✓	1st
https://biermetstijl.com/wp-content/plugins/sellkit-pro/assets/dist/js/elementor-init.min.js?ver=2.2.0	12 KB	—	✓	1st
https://c0.wp.com/p/woocommerce/11.2.1/assets/js/js-cookie/js.cookie.min.js	1 KB	—	✓	3rd
https://c0.wp.com/c/7.1.3/wp-includes/js/dist/hooks.min.js	2 KB	—	✓	3rd
https://c0.wp.com/c/7.1.3/wp-includes/js/dist/i18n.min.js	3 KB	—	✓	3rd
https://biermetstijl.com/wp-content/plugins/contact-form-7/includes/swv/js/index.js?ver=6.2.3	4 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

Page Weight Inventory

Action

318 resources · 6.3 MB · 305 KB savings available

FIX

318 resources · 6.3 MB · 305 KB savings available

Page weight 6.3 MB exceeds 1 MB target by 5.3 MB

Got: 6.3 MB Expected: ≤ 1 MB

~305 KB of savings available

242 third-party resources (72% of weight)

7 resources over 200KB

318 resources · 6.3 MiB · 242 third-party 5.3 MiB over 1MB target

JavaScript 35% · 2.2 MiB

Other 23% · 1.5 MiB

Image 21% · 1.3 MiB

Font 13% · 830.1 KiB

CSS 5% · 349.5 KiB

Document 2% · 128.1 KiB

~304.8 KiB of savings available

Remove unused JavaScript: 304.8 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

318 resources			6.3 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

19 images, 0 KB saveable

REVIEW

19 images, 0 KB saveable

All images are well-optimized

19 images 1.3 MB

0 oversized -0 KB

16 legacy format

0 missing dimensions CLS risk

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.

Document Compression

Document response uses gzip; brotli would be ~20% smaller

REVIEW

Document response uses gzip; brotli would be ~20% smaller

Main HTML response uses gzip (brotli would be ~20% smaller)

All current browsers support brotli. Most CDNs (Cloudflare, Fastly, AWS CloudFront, Vercel, Netlify) can switch from gzip to brotli with a single config flag. Origin servers (nginx, Apache) need a brotli module compiled in -- nginx-brotli or Apache mod_brotli.

Main HTML Cache-Control

No Cache-Control header on main HTML response

REVIEW

No Cache-Control header on main HTML response

Main HTML response has no Cache-Control header

Without an explicit Cache-Control, browsers fall back to heuristic caching (~10% of Last-Modified age). Set `Cache-Control: no-cache` or `max-age=300` for HTML to control freshness explicitly -- prevents stale auth state and SPA shell drift.

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.

JavaScript Blocking

2 JS blocking issue(s) detected

REVIEW

2 JS blocking issue(s) detected

38 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.

Total JS execution time is 7.0 s -- over the 3.5s budget

Total JavaScript execution (parse + compile + run) across all scripts exceeds 3.5 seconds. On low-end devices that becomes 7-15+ seconds and shows up directly in TBT and INP. Reduce by: tree-shaking unused dependencies, code-splitting (dynamic `import()`), removing or deferring third-party tracking, and replacing heavy frameworks where they're not needed.

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

A+

Text Compression

All text resources are compressed

PASS

All text resources are compressed

All text resources are properly compressed.

A+

Font Loading

154 fonts (830 KB)

PASS

154 fonts (830 KB)

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

Web fonts

154

830 KB total

Render-blocking

of 154

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

opensans-memtyags126miz... woff2 swap

Size 0 KB

Load time 0 ms

Start 4.7 s