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Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
92
GRADE
A
FIX
0
REVIEW
4
PASS
11
INFO
2

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

Mobile Desktop
98
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
93
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.

1.05 s

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

2.25 s

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

87 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.

1.05 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.

5.09 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
17
11 PASS 4 REVIEW
B
Third-Party Impact
50% third-party, 0 ms blocking
REVIEW
50% third-party, 0 ms blocking
Info::
Third-party code accounts for 50% of page weight (217.7 KiB of 439.3 KiB)
Info::
Third-party blocking time is low (0 ms)
50%
50%
First-party Third-party
B
JS Execution Cost
542ms total JS execution
REVIEW
542ms total JS execution
Info::
https://jekyllrb.com/: 200ms CPU time
Info::
Unattributable: 147ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-GJE5...: 144ms CPU time
Info::
https://www.google-analytics.com/analytics.js: 51ms CPU time
Warning::
Third-party scripts: 342ms (63% of total)

Main Thread Breakdown

Script Evaluation 46% Other 21% Style & Layout 19% Script Parsing & Compilation 9%
ScriptTotalScriptingParse/CompileParty
https://jekyllrb.com/200ms44ms3ms1st
Unattributable147ms47ms0ms3rd
https://www.googletagmanager.com/gtag/js?id=G-GJE5T10EDG&cx=c&_slc=1144ms111ms31ms3rd
https://www.google-analytics.com/analytics.js51ms42ms4ms3rd
B
JS Bundles
3 scripts, 90 KB unused
REVIEW
3 scripts, 90 KB unused
Warning::
https://www.googletagmanager.com/gtag/js?id=G-GJE5...: 64 KB unused (43%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cdn.jsdelivr.net/npm/docsearch.js@2/dist/c...: 26 KB unused (56%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 90 KB
90 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtag/js?id=G-GJE5T10EDG&cx=c&_slc=1148 KB64 KB (43%)✓3rd
https://cdn.jsdelivr.net/npm/docsearch.js@2/dist/cdn/docsearch.min.js48 KB26 KB (56%)✓3rd
https://www.google-analytics.com/analytics.js21 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

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

Green Hosting

No green hosting detected

A+
Page Weight Budget
439 KB transferred, 17 requests
PASS
439 KB transferred, 17 requests
Info::
Page weighs 917 KB (439 KB transferred)
Info::
17 HTTP requests
Info::
Estimated 0.09 g CO2 per page load
439 KB / 2.4 MB budget
439 KB transferred
17 requests
0.09 g CO2 per page load
JavaScript 216.7 KiB 49%
Fonts 131.5 KiB 30%
Images 71.0 KiB 16%
CSS 13.7 KiB 3%
HTML 3.7 KiB 1%
Other 1.6 KiB 0%
Other 547 B 0%
Other 463 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
3 images, 0 KB saveable
PASS
3 images, 0 KB saveable
Info::
All images are well-optimized
3 images 71 KB
0 oversized -0 KB
3 legacy format
0 missing dimensions CLS risk
A+
Font Loading
6 fonts (132 KB)
PASS
6 fonts (132 KB)
Info::
6 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

6

132 KB total

Render-blocking

0

of 6

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s 1.5 s 2.0 s FCP 1.0 s LCP 2.2 shttps://jekyllrb.com/fonts/lato-v14-latin-300.woff2lato-v14-latin-300.woff2 https://jekyllrb.com/fonts/lato-v14-latin-300.woff2 — 22.9 KiB — 134 ms — font-display: swaphttps://jekyllrb.com/fonts/lato-v14-latin-700.woff2lato-v14-latin-700.woff2 https://jekyllrb.com/fonts/lato-v14-latin-700.woff2 — 22.5 KiB — 143 ms — font-display: swaphttps://jekyllrb.com/fonts/lato-v14-latin-900.woff2lato-v14-latin-900.woff2 https://jekyllrb.com/fonts/lato-v14-latin-900.woff2 — 22.1 KiB — 157 ms — font-display: swaphttps://jekyllrb.com/fonts/lato-v14-latin-300italic.woff2lato-v14-latin-300itali... https://jekyllrb.com/fonts/lato-v14-latin-300italic.woff2 — 17.3 KiB — 174 ms — font-display: swaphttps://jekyllrb.com/fonts/lato-v14-latin-700italic.woff2lato-v14-latin-700itali... https://jekyllrb.com/fonts/lato-v14-latin-700italic.woff2 — 23.8 KiB — 202 ms — font-display: swaphttps://jekyllrb.com/fonts/lato-v14-latin-regular.woff2lato-v14-latin-regular.... https://jekyllrb.com/fonts/lato-v14-latin-regular.woff2 — 23.0 KiB — 167 ms — font-display: swap
lato-v14-latin-300.woff2 woff2 swap
Size 23 KB
Load time 134 ms
Start 23 ms
Risk FOUT — text flashes from fallback to web font
lato-v14-latin-700.woff2 woff2 swap
Size 22 KB
Load time 143 ms
Start 24 ms
Risk FOUT — text flashes from fallback to web font
lato-v14-latin-900.woff2 woff2 swap
Size 22 KB
Load time 157 ms
Start 206 ms
Risk FOUT — text flashes from fallback to web font
lato-v14-latin-300itali... woff2 swap
Size 17 KB
Load time 174 ms
Start 206 ms
Risk FOUT — text flashes from fallback to web font
lato-v14-latin-700itali... woff2 swap
Size 24 KB
Load time 202 ms
Start 206 ms
Risk FOUT — text flashes from fallback to web font
lato-v14-latin-regular.... woff2 swap
Size 23 KB
Load time 167 ms
Start 208 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)
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
3 hints, 0 missing preconnects
PASS
3 hints, 0 missing preconnects
Info::
Page uses 3 resource hint(s)

Current Resource Hints

preconnect
—
preload
3
dns-prefetch
—
prefetch
—

3 resource hints configured

A
Page Weight Inventory
17 resources · 439 KB · 90 KB savings available
PASS
17 resources · 439 KB · 90 KB savings available
Info::
Within 1MB page-weight target
Got: 439 KB
Info::
~90 KB of savings available
Warning::
5 third-party resources (50% of weight)
17 resources · 439.3 KiB · 5 third-party Within 1MB page-weight target
JavaScript 49% · 216.7 KiB
Font 30% · 131.5 KiB
Image 17% · 72.7 KiB
CSS 3% · 13.7 KiB
Document 1% · 3.7 KiB
Other 0% · 1010 B

~90.1 KiB of savings available

Remove unused JavaScript: 90.1 KiB
A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
A+
HTTP Caching
max-age=600 (10 minutes)
PASS
max-age=600 (10 minutes)
Info::
Cache-Control header is set
Got: max-age=600
Info::
Effective TTL: 10 minutes (max-age=600)
Info::
ETag present — enables conditional (304) responses
Info::
Last-Modified header present
Cache-Control

max-age=600

DirectiveValueMeaning
max-age600Cache for 10 minutes
Effective TTL: 600 seconds
Network Waterfall
17 requests over 633ms
INFO
0 ms 500 ms 1.0 s 1.5 s 2.0 s FCP 1.0 s LCP 2.2 shttps://jekyllrb.com// https://jekyllrb.com/ — 200 — 3.7 KiB — 12 ms — h2https://jekyllrb.com/fonts/lato-v14-latin-300.woff2/fonts/lato-v14-latin-300.woff2 https://jekyllrb.com/fonts/lato-v14-latin-300.woff2 — 200 — 22.9 KiB — 134 ms — h2https://jekyllrb.com/fonts/lato-v14-latin-700.woff2/fonts/lato-v14-latin-700.woff2 https://jekyllrb.com/fonts/lato-v14-latin-700.woff2 — 200 — 22.5 KiB — 143 ms — h2https://jekyllrb.com/css/screen.css/css/screen.css https://jekyllrb.com/css/screen.css — 200 — 13.7 KiB — 151 ms — h2https://jekyllrb.com/img/octojekyll.png/img/octojekyll.png https://jekyllrb.com/img/octojekyll.png — 200 — 22.1 KiB — 164 ms — h2https://cdn.jsdelivr.net/npm/docsearch.js@2/dist/cdn/docsearch.min.jscdn.jsdelivr.net/npm/docsearch.js@2... https://cdn.jsdelivr.net/npm/docsearch.js@2/dist/cdn/docsearch.min.js — 200 — 47.8 KiB — 94 ms — h2https://jekyllrb.com/img/logo-2x.png/img/logo-2x.png https://jekyllrb.com/img/logo-2x.png — 200 — 45.2 KiB — 148 ms — h2https://jekyllrb.com/img/footer-logo.png/img/footer-logo.png https://jekyllrb.com/img/footer-logo.png — 200 — 3.7 KiB — 134 ms — h2https://jekyllrb.com/fonts/lato-v14-latin-900.woff2/fonts/lato-v14-latin-900.woff2 https://jekyllrb.com/fonts/lato-v14-latin-900.woff2 — 200 — 22.1 KiB — 157 ms — h2https://jekyllrb.com/fonts/lato-v14-latin-300italic.woff2/fonts/lato-v14-latin-300italic.wof... https://jekyllrb.com/fonts/lato-v14-latin-300italic.woff2 — 200 — 17.3 KiB — 174 ms — h2https://jekyllrb.com/fonts/lato-v14-latin-700italic.woff2/fonts/lato-v14-latin-700italic.wof... https://jekyllrb.com/fonts/lato-v14-latin-700italic.woff2 — 200 — 23.8 KiB — 202 ms — h2https://jekyllrb.com/fonts/lato-v14-latin-regular.woff2/fonts/lato-v14-latin-regular.woff2 https://jekyllrb.com/fonts/lato-v14-latin-regular.woff2 — 200 — 23.0 KiB — 167 ms — h2https://www.google-analytics.com/analytics.jswww.google-analytics.com/analytics.... https://www.google-analytics.com/analytics.js — 200 — 20.9 KiB — 98 ms — h2https://www.google-analytics.com/j/collect?v=1&_v=j102&a=573515282&t=pageview&_s=1&dl=https%3A%2F%2Fjekyllrb.com%2F&ul=en-us&dt=Jekyll%20%E2%80%A2%20Simple%2C%20blog-aware%2C%20static%20sites%20%7C%20Transform%20your%20plain%20text%20into%20static%20websites%20and%20blogs&sr=412x823&vp=412x823&_u=IEBAAAABAAAAACAAI~&jid=1297603532&gjid=2015587857&cid=266462361.1776816384&tid=UA-50755011-1&_gid=621608042.1776816384&_r=1&_slc=1&z=1676816489www.google-analytics.com/j/collect?... https://www.google-analytics.com/j/collect?v=1&_v=j102&a=573515282&t=pageview&_s=1&dl=https%3A%2F%2Fjekyllrb.com%2F&ul=en-us&dt=Jekyll%20%E2%80%A2%20Simple%2C%20blog-aware%2C%20static%20sites%20%7C%20Transform%20your%20plain%20text%20into%20static%20websites%20and%20blogs&sr=412x823&vp=412x823&_u=IEBAAAABAAAAACAAI~&jid=1297603532&gjid=2015587857&cid=266462361.1776816384&tid=UA-50755011-1&_gid=621608042.1776816384&_r=1&_slc=1&z=1676816489 — 200 — 463 B — 25 ms — h2https://www.googletagmanager.com/gtag/js?id=G-GJE5T10EDG&cx=c&_slc=1www.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=G-GJE5T10EDG&cx=c&_slc=1 — 200 — 148.0 KiB — 165 ms — h2https://region1.google-analytics.com/g/collect?v=2&tid=G-GJE5T10EDG&gtm=45je64h1v9124045930za20g&_p=1776816384225&gcd=13l3l3l2l2l1&npa=0&dma_cps=a&dma=1&_eu=EBAI&are=1&cid=266462361.1776816384&frm=0&ir=1&pscdl=noapi&rcb=9&sr=412x823&uaa=&uab=64&uafvl=Chromium%3B147.0.7727.101%7CNot.A%252FBrand%3B8.0.0.0&uam=moto%20g%20power%20(2022)&uamb=1&uap=Android&uapv=11.0&uaw=0&ul=en-us&_s=1&tag_exp=0~115616986~115938465~115938469~117266401~117512542&dl=https%3A%2F%2Fjekyllrb.com%2F&dt=Jekyll%20%E2%80%A2%20Simple%2C%20blog-aware%2C%20static%20sites%20%7C%20Transform%20your%20plain%20text%20into%20static%20websites%20and%20blogs&sid=1776816384&sct=1&seg=0&_tu=wAQ&en=page_view&_fv=1&_ss=1&_ee=1&tfd=564region1.google-analytics.com/g/coll... https://region1.google-analytics.com/g/collect?v=2&tid=G-GJE5T10EDG&gtm=45je64h1v9124045930za20g&_p=1776816384225&gcd=13l3l3l2l2l1&npa=0&dma_cps=a&dma=1&_eu=EBAI&are=1&cid=266462361.1776816384&frm=0&ir=1&pscdl=noapi&rcb=9&sr=412x823&uaa=&uab=64&uafvl=Chromium%3B147.0.7727.101%7CNot.A%252FBrand%3B8.0.0.0&uam=moto%20g%20power%20(2022)&uamb=1&uap=Android&uapv=11.0&uaw=0&ul=en-us&_s=1&tag_exp=0~115616986~115938465~115938469~117266401~117512542&dl=https%3A%2F%2Fjekyllrb.com%2F&dt=Jekyll%20%E2%80%A2%20Simple%2C%20blog-aware%2C%20static%20sites%20%7C%20Transform%20your%20plain%20text%20into%20static%20websites%20and%20blogs&sid=1776816384&sct=1&seg=0&_tu=wAQ&en=page_view&_fv=1&_ss=1&_ee=1&tfd=564 — 204 — 547 B — 69 ms — h2https://jekyllrb.com/favicon.ico/favicon.ico https://jekyllrb.com/favicon.ico — 200 — 1.6 KiB — 3 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
63% of JavaScript execution is third-party
First-party Third-party 342ms · 169KB · $1/mo
Unattributable
Other
Optional
Execution 147ms
Transfer 0 KB
Monthly Cost $0/mo
Google Tag Manager
Tag Manager
Optional
Execution 144ms
Transfer 148 KB
Unused 43%
Monthly Cost $0/mo
Google Analytics
Analytics
Optional
Execution 51ms
Transfer 21 KB
Monthly Cost $0/mo

63% 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.

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