Skip to content
https://developer.wordpress.org

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
88
GRADE
B
FIX
1
REVIEW
3
PASS
8
INFO
2

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

Mobile Desktop
100
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
98
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
100
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.

467 ms

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

801 ms

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

14 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.

633 ms

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

1.16 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
14
8 PASS 3 REVIEW 1 FIX
F
HTTP Caching
Action
No cache headers
FIX
No cache headers
Warning::
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.

B
Third-Party Impact
40% third-party, 0 ms blocking
REVIEW
40% third-party, 0 ms blocking
Info::
Third-party code accounts for 40% of page weight (309.4 KiB of 766.3 KiB)
Info::
Third-party blocking time is low (0 ms)
60%
40%
First-party Third-party
B
JS Bundles
26 scripts, 132 KB unused
REVIEW
26 scripts, 132 KB unused
Warning::
https://www.googletagmanager.com/gtag/js?id=G-CG6G...: 69 KB unused (40%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-P24...: 64 KB unused (49%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 132 KB
132 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtag/js?id=G-CG6GJ50G8J&cx=c&gtm=4e6411h1170 KB69 KB (40%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-P24PF4B130 KB64 KB (49%)✓3rd
https://developer.wordpress.org/wp-content/plugins/gutenberg/build/scripts/hooks/index.min.js?ver=7496969728ca0f95732d2 KB—✓1st
https://developer.wordpress.org/wp-content/mu-plugins/pub-sync/blocks/time/build/view.js?ver=385bfe9134bf98c52dda1 KB—✓1st
https://developer.wordpress.org/wp-content/plugins/handbook/scripts/handbook.js?ver=201509301 KB—✓1st
https://developer.wordpress.org/wp-content/plugins/gutenberg/build/modules/interactivity/index.min.js?ver=4d2a3a72c7410d54888115 KB—✓1st
https://developer.wordpress.org/wp-content/plugins/gutenberg/build/modules/block-library/navigation/view.min.js?ver=96a846e1d7b789c39ab9-202403081 KB—✓1st
https://developer.wordpress.org/wp-content/plugins/code-syntax-block/assets/prism/prism.js?ver=174826508511 KB—✓1st
https://developer.wordpress.org/wp-content/plugins/gutenberg/build/scripts/i18n/index.min.js?ver=781d11515ad3d91786ec3 KB—✓1st
https://developer.wordpress.org/wp-content/themes/wporg-developer-2023/js/awesomplete.min.js?ver=17482649902 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

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
Page Weight Budget
766 KB transferred, 51 requests
PASS
766 KB transferred, 51 requests
Info::
Page weighs 2.0 MB (766 KB transferred)
Info::
51 HTTP requests
Info::
Estimated 0.16 g CO2 per page load
766 KB / 2.4 MB budget
766 KB transferred
51 requests
0.16 g CO2 per page load
JavaScript 398.1 KiB 52%
Fonts 187.0 KiB 24%
CSS 143.9 KiB 19%
HTML 28.5 KiB 4%
Images 6.5 KiB 1%
Other 1.7 KiB 0%
Other 554 B 0%
0 2.4 MB 4.9 MB
Under budget
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
Image Optimization
4 images, 0 KB saveable
PASS
4 images, 0 KB saveable
Info::
All images are well-optimized
4 images 6 KB
0 oversized -0 KB
3 legacy format
0 missing dimensions CLS risk
A+
JS Execution Cost
347ms total JS execution
PASS
347ms total JS execution
Info::
https://developer.wordpress.org/: 123ms CPU time
Info::
Unattributable: 86ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-CG6G...: 81ms CPU time
Info::
https://www.googletagmanager.com/gtm.js?id=GTM-P24...: 57ms CPU time
Warning::
Third-party scripts: 224ms (65% of total)

Main Thread Breakdown

Script Evaluation 43% Other 19% Style & Layout 18% Parse HTML & CSS 9% Script Parsing & Compilation 9%
ScriptTotalScriptingParse/CompileParty
https://developer.wordpress.org/123ms2ms2ms1st
Unattributable86ms23ms0ms3rd
https://www.googletagmanager.com/gtag/js?id=G-CG6GJ50G8J&cx=c&gtm=4e6411h181ms65ms16ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-P24PF4B57ms45ms12ms3rd
A+
Font Loading
3 fonts (187 KB)
PASS
3 fonts (187 KB)
Info::
3 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

3

187 KB total

Render-blocking

0

of 3

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 467 ms LCP 801 mshttps://developer.wordpress.org/wp-content/mu-plugins/pub-sync/global-fonts/Inter/Inter-latin.woff2Inter-latin.woff2 https://developer.wordpress.org/wp-content/mu-plugins/pub-sync/global-fonts/Inter/Inter-latin.woff2 — 76.0 KiB — 0 ms — font-display: swaphttps://developer.wordpress.org/wp-content/mu-plugins/pub-sync/global-fonts/EB-Garamond/EBGaramond-latin.woff2EBGaramond-latin.woff2 https://developer.wordpress.org/wp-content/mu-plugins/pub-sync/global-fonts/EB-Garamond/EBGaramond-latin.woff2 — 108.5 KiB — 0 ms — font-display: swaphttps://developer.wordpress.org/wp-content/mu-plugins/pub-sync/global-fonts/Inter/Inter-arrows.woff2Inter-arrows.woff2 https://developer.wordpress.org/wp-content/mu-plugins/pub-sync/global-fonts/Inter/Inter-arrows.woff2 — 2.5 KiB — 0 ms — font-display: swap
Inter-latin.woff2 woff2 swap
Size 76 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
EBGaramond-latin.woff2 woff2 swap
Size 108 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
Inter-arrows.woff2 woff2 swap
Size 3 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 ~54 KB and ~108 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
Network Waterfall
51 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
65% of JavaScript execution is third-party
First-party Third-party 224ms · 300KB · $3/mo
Unattributable
Other
Optional
Execution 86ms
Transfer 0 KB
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 81ms
Transfer 170 KB
Unused 40%
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 57ms
Transfer 130 KB
Unused 49%
Monthly Cost $1/mo

65% 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

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.

Send Feedback