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Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
85
GRADE
B
FIX
2
REVIEW
5
PASS
8
INFO
2

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

Mobile Desktop
36
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
100
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
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.

3.88 s

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

8.84 s

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

366 ms

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

0.522

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

3.88 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.

9.09 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
8 PASS 5 REVIEW 2 FIX
D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (976.7 KiB of 976.9 KiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
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
Image Optimization
2 images, 0 KB saveable
REVIEW
2 images, 0 KB saveable
Warning::
https://storage.ghost.io/c/d1/ab/d1ab7f97-66a2-404... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://storage.ghost.io/c/d1/ab/d1ab7f97-66a2-404... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
2 images 138 KB
0 oversized -0 KB
2 legacy format
2 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

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

C
JS Execution Cost
Action
1504ms total JS execution
REVIEW
1504ms total JS execution
Warning::
https://cdn.jsdelivr.net/ghost/portal@~2.68/umd/po...: 489ms CPU time
Info::
https://ilya.grigorik.com/: 243ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-LCVW...: 236ms CPU time
Info::
https://ilya.grigorik.com/assets/js/app.min.js?v=3...: 235ms CPU time
Info::
Unattributable: 168ms CPU time
Warning::
Third-party scripts: 1504ms (100% of total)

Main Thread Breakdown

Script Evaluation 48% Script Parsing & Compilation 20% Other 14% Style & Layout 14%
ScriptTotalScriptingParse/CompileParty
https://cdn.jsdelivr.net/ghost/portal@~2.68/umd/portal.min.js489ms292ms194ms3rd
https://ilya.grigorik.com/243ms16ms3ms3rd
https://www.googletagmanager.com/gtag/js?id=G-LCVWBFR9YN236ms198ms36ms3rd
https://ilya.grigorik.com/assets/js/app.min.js?v=35da3834ca235ms84ms49ms3rd
Unattributable168ms26ms0ms3rd
https://cdn.jsdelivr.net/ghost/sodo-search@~1.8/umd/sodo-search.min.js133ms102ms28ms3rd
C
JS Bundles
Action
7 scripts, 240 KB unused
REVIEW
7 scripts, 240 KB unused
Warning::
https://cdn.jsdelivr.net/ghost/portal@~2.68/umd/po...: 91 KB unused (23%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-LCVW...: 67 KB unused (43%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cdn.jsdelivr.net/ghost/sodo-search@~1.8/um...: 54 KB unused (56%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://ilya.grigorik.com/assets/js/app.min.js?v=3...: 28 KB unused (50%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 240 KB
240 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://cdn.jsdelivr.net/ghost/portal@~2.68/umd/portal.min.js436 KB91 KB (23%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-LCVWBFR9YN155 KB67 KB (43%)✓3rd
https://cdn.jsdelivr.net/ghost/sodo-search@~1.8/umd/sodo-search.min.js98 KB54 KB (56%)✓3rd
https://ilya.grigorik.com/assets/js/app.min.js?v=35da3834ca58 KB28 KB (50%)✓3rd
https://ilya.grigorik.com/public/cards.min.js?v=35da3834ca2 KB—✓3rd
https://ilya.grigorik.com/public/member-attribution.min.js?v=35da3834ca2 KB—✓3rd
https://ilya.grigorik.com/public/ghost-stats.min.js?v=35da3834ca13 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

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

B
Page Weight Inventory
25 resources · 977 KB · 240 KB savings available
REVIEW
25 resources · 977 KB · 240 KB savings available
Info::
Within 1MB page-weight target
Got: 977 KB
Info::
~240 KB of savings available
Warning::
24 third-party resources (100% of weight)
Info::
1 resources over 200KB
25 resources · 976.9 KiB · 24 third-party Within 1MB page-weight target
JavaScript 78% · 762.9 KiB
Image 15% · 143.5 KiB
Font 4% · 39.3 KiB
Document 2% · 19.6 KiB
CSS 1% · 7.2 KiB
Other 0% · 4.4 KiB

~240.2 KiB of savings available

Remove unused JavaScript: 240.2 KiB
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
Page Weight Budget
977 KB transferred, 25 requests
PASS
977 KB transferred, 25 requests
Info::
Page weighs 3.3 MB (977 KB transferred)
Warning::
JavaScript is 763 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 763 KB
Info::
25 HTTP requests
Info::
Estimated 0.20 g CO2 per page load
977 KB / 2.4 MB budget
977 KB transferred
25 requests
0.20 g CO2 per page load
JavaScript 762.9 KiB 78%
Images 137.7 KiB 14%
Fonts 39.3 KiB 4%
HTML 19.3 KiB 2%
CSS 7.2 KiB 1%
Other 6.1 KiB 1%
Other 4.4 KiB 0%
Other 0 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

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+
Font Loading
1 fonts (39 KB)
PASS
1 fonts (39 KB)
Info::
1 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

1

39 KB total

Render-blocking

0

of 1

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s 6.0 s 7.0 s 8.0 s 9.0 s FCP 3.9 s LCP 8.8 shttps://fonts.gstatic.com/s/ibmplexsans/v23/zYXzKVElMYYaJe8bpLHnCwDKr932-G7dytD-Dmu1syxeKYbSB4Zh.woff2zYXzKVElMYYaJe8bpLHnCwD... https://fonts.gstatic.com/s/ibmplexsans/v23/zYXzKVElMYYaJe8bpLHnCwDKr932-G7dytD-Dmu1syxeKYbSB4Zh.woff2 — 39.3 KiB — 37 ms — font-display: swap
zYXzKVElMYYaJe8bpLHnCwD... woff2 swap
Size 39 KB
Load time 37 ms
Start 972 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
2 hints, 0 missing preconnects
PASS
2 hints, 0 missing preconnects
Info::
Page uses 2 resource hint(s)

Current Resource Hints

preconnect
1
preload
1
dns-prefetch
—
prefetch
—

2 resource hints configured

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
Network Waterfall
25 requests over 1387ms
INFO
0 ms 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s 6.0 s 7.0 s 8.0 s 9.0 s FCP 3.9 s LCP 8.8 shttps://igvita.com// https://igvita.com/ — 301 — 189 B — 484 ms — h2https://www.igvita.com/www.igvita.com/ https://www.igvita.com/ — 301 — 190 B — 159 ms — h2https://ilya.grigorik.com/ilya.grigorik.com/ https://ilya.grigorik.com/ — 200 — 19.3 KiB — 15 ms — h2https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@400;500;600;700&display=swapfonts.googleapis.com/css2?family=IB... https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@400;500;600;700&display=swap — 200 — 1.2 KiB — 93 ms — h2https://cdn.jsdelivr.net/ghost/portal@~2.68/umd/portal.min.jscdn.jsdelivr.net/ghost/portal@~2.68... https://cdn.jsdelivr.net/ghost/portal@~2.68/umd/portal.min.js — 200 — 436.2 KiB — 62 ms — h2https://ilya.grigorik.com/public/cards.min.css?v=35da3834cailya.grigorik.com/public/cards.min.... https://ilya.grigorik.com/public/cards.min.css?v=35da3834ca — 200 — 6.0 KiB — 33 ms — h2https://storage.ghost.io/c/d1/ab/d1ab7f97-66a2-4047-a903-af92b763a683/content/images/2022/06/logo.svgstorage.ghost.io/c/d1/ab/d1ab7f97-6... https://storage.ghost.io/c/d1/ab/d1ab7f97-66a2-4047-a903-af92b763a683/content/images/2022/06/logo.svg — 200 — 3.2 KiB — 53 ms — h2https://ilya.grigorik.com/assets/js/app.min.js?v=35da3834cailya.grigorik.com/assets/js/app.min... https://ilya.grigorik.com/assets/js/app.min.js?v=35da3834ca — 200 — 57.6 KiB — 38 ms — h2https://cdn.jsdelivr.net/ghost/sodo-search@~1.8/umd/sodo-search.min.jscdn.jsdelivr.net/ghost/sodo-search@... https://cdn.jsdelivr.net/ghost/sodo-search@~1.8/umd/sodo-search.min.js — 200 — 97.7 KiB — 42 ms — h2https://ilya.grigorik.com/public/cards.min.js?v=35da3834cailya.grigorik.com/public/cards.min.... https://ilya.grigorik.com/public/cards.min.js?v=35da3834ca — 200 — 1.8 KiB — 35 ms — h2https://ilya.grigorik.com/public/member-attribution.min.js?v=35da3834cailya.grigorik.com/public/member-att... https://ilya.grigorik.com/public/member-attribution.min.js?v=35da3834ca — 200 — 1.5 KiB — 31 ms — h2https://ilya.grigorik.com/public/ghost-stats.min.js?v=35da3834cailya.grigorik.com/public/ghost-stat... https://ilya.grigorik.com/public/ghost-stats.min.js?v=35da3834ca — 200 — 12.8 KiB — 30 ms — h2https://www.googletagmanager.com/gtag/js?id=G-LCVWBFR9YNwww.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=G-LCVWBFR9YN — 200 — 155.3 KiB — 168 ms — h2https://storage.ghost.io/c/d1/ab/d1ab7f97-66a2-4047-a903-af92b763a683/content/images/size/w1080/2022/06/ilya-waist.jpgstorage.ghost.io/c/d1/ab/d1ab7f97-6... https://storage.ghost.io/c/d1/ab/d1ab7f97-66a2-4047-a903-af92b763a683/content/images/size/w1080/2022/06/ilya-waist.jpg — 200 — 134.5 KiB — 5 ms — h2https://ilya.grigorik.com/members/api/member/ilya.grigorik.com/members/api/membe... https://ilya.grigorik.com/members/api/member/ — 204 — 246 B — 76 ms — h2https://fonts.gstatic.com/s/ibmplexsans/v23/zYXzKVElMYYaJe8bpLHnCwDKr932-G7dytD-Dmu1syxeKYbSB4Zh.woff2fonts.gstatic.com/s/ibmplexsans/v23... https://fonts.gstatic.com/s/ibmplexsans/v23/zYXzKVElMYYaJe8bpLHnCwDKr932-G7dytD-Dmu1syxeKYbSB4Zh.woff2 — 200 — 39.3 KiB — 37 ms — h3https://igrigorik.ghost.io/ghost/api/content/settings/?key=0199552185a0b8b40738c405baigrigorik.ghost.io/ghost/api/conten... https://igrigorik.ghost.io/ghost/api/content/settings/?key=0199552185a0b8b40738c405ba — 204 — 0 B — 41 ms — h2https://igrigorik.ghost.io/ghost/api/content/tiers/?limit=100&include=monthly_price%2Cyearly_price%2Cbenefits&key=0199552185a0b8b40738c405baigrigorik.ghost.io/ghost/api/conten... https://igrigorik.ghost.io/ghost/api/content/tiers/?limit=100&include=monthly_price%2Cyearly_price%2Cbenefits&key=0199552185a0b8b40738c405ba — 204 — 0 B — 41 ms — h2https://igrigorik.ghost.io/ghost/api/content/newsletters/?limit=100&key=0199552185a0b8b40738c405baigrigorik.ghost.io/ghost/api/conten... https://igrigorik.ghost.io/ghost/api/content/newsletters/?limit=100&key=0199552185a0b8b40738c405ba — 204 — 0 B — 40 ms — h2https://igrigorik.ghost.io/ghost/api/content/settings/?key=0199552185a0b8b40738c405baigrigorik.ghost.io/ghost/api/conten... https://igrigorik.ghost.io/ghost/api/content/settings/?key=0199552185a0b8b40738c405ba — 200 — 2.1 KiB — 36 ms — h2https://igrigorik.ghost.io/ghost/api/content/newsletters/?limit=100&key=0199552185a0b8b40738c405baigrigorik.ghost.io/ghost/api/conten... https://igrigorik.ghost.io/ghost/api/content/newsletters/?limit=100&key=0199552185a0b8b40738c405ba — 200 — 701 B — 37 ms — h2https://igrigorik.ghost.io/ghost/api/content/tiers/?limit=100&include=monthly_price%2Cyearly_price%2Cbenefits&key=0199552185a0b8b40738c405baigrigorik.ghost.io/ghost/api/conten... https://igrigorik.ghost.io/ghost/api/content/tiers/?limit=100&include=monthly_price%2Cyearly_price%2Cbenefits&key=0199552185a0b8b40738c405ba — 200 — 569 B — 30 ms — h2https://region1.google-analytics.com/g/collect?v=2&tid=G-LCVWBFR9YN&gtm=45je64k0h2v896048868za200zd896048868&_p=1776804573056&gcd=13l3l3l2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1119128878.1776804573&frm=0&pscdl=noapi&rcb=13&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=0~115938465~115938469~117266400&sid=1776804573&sct=1&seg=0&dl=https%3A%2F%2Filya.grigorik.com%2F&dt=Ilya%20Grigorik&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=1039region1.google-analytics.com/g/coll... https://region1.google-analytics.com/g/collect?v=2&tid=G-LCVWBFR9YN&gtm=45je64k0h2v896048868za200zd896048868&_p=1776804573056&gcd=13l3l3l2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1119128878.1776804573&frm=0&pscdl=noapi&rcb=13&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=0~115938465~115938469~117266400&sid=1776804573&sct=1&seg=0&dl=https%3A%2F%2Filya.grigorik.com%2F&dt=Ilya%20Grigorik&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=1039 — 204 — 550 B — 79 ms — h2https://storage.ghost.io/c/d1/ab/d1ab7f97-66a2-4047-a903-af92b763a683/content/images/size/w256h256/format/png/2022/06/icon-1.svgstorage.ghost.io/c/d1/ab/d1ab7f97-6... https://storage.ghost.io/c/d1/ab/d1ab7f97-66a2-4047-a903-af92b763a683/content/images/size/w256h256/format/png/2022/06/icon-1.svg — 200 — 5.7 KiB — 4 ms — h3https://ilya.grigorik.com/.ghost/analytics/api/v1/page_hit?name=analytics_eventsilya.grigorik.com/.ghost/analytics/... https://ilya.grigorik.com/.ghost/analytics/api/v1/page_hit?name=analytics_events — 202 — 316 B — 138 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
100% of JavaScript execution is third-party
First-party Third-party 1504ms · 766KB · $5/mo
jsDelivr
CDN
Costly
Execution 489ms
Transfer 436 KB
Unused 23%
Monthly Cost $2/mo
ilya.grigorik.com
Other
Costly
Execution 243ms
Transfer 19 KB
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Costly
Execution 236ms
Transfer 155 KB
Unused 43%
Monthly Cost $1/mo
ilya.grigorik.com
Other
Costly
Execution 235ms
Transfer 58 KB
Unused 50%
Monthly Cost $1/mo
Unattributable
Other
Optional
Execution 168ms
Transfer 0 KB
Monthly Cost $1/mo
jsDelivr
CDN
Optional
Execution 133ms
Transfer 98 KB
Unused 56%
Monthly Cost $0/mo

These scripts may cost more than they're worth

  • jsDelivr adds 489ms and costs ~$2/month
  • ilya.grigorik.com adds 243ms and costs ~$1/month
  • Google Tag Manager adds 236ms and costs ~$1/month
  • ilya.grigorik.com adds 235ms and costs ~$1/month

100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.

Why this matters

When third-party JS execution time exceeds your own, performance gains from frontend work are capped by code you don't own.

Learn more ▾

Every millisecond of third-party JS competes with your own for main-thread time. If their share is bigger than yours, optimization on your code base barely moves the needle. Audit, defer, or remove third-parties before further frontend optimization. Use Lighthouse's third-party audit to identify the worst offenders.

Source: web.dev

jsDelivr takes 489ms 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

ilya.grigorik.com takes 243ms 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

Google Tag Manager takes 236ms 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

ilya.grigorik.com takes 235ms 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

56% of jsDelivr'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

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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