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https://zenwriting.net

Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
92
GRADE
A
FIX
2
REVIEW
1
PASS
12
INFO
2

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

Mobile Desktop
88
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.

3.10 s

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

3.10 s

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

0 ms

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

0.022

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

3.10 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.

3.10 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
12 PASS 1 REVIEW 2 FIX
D
Third-Party Impact
Action
64% third-party, 0 ms blocking
FIX
64% third-party, 0 ms blocking
Warning::
Third-party code accounts for 64% of page weight (81.3 KiB of 126.1 KiB)
Info::
Third-party blocking time is low (0 ms)
36%
64%
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.

C
Image Optimization
Action
4 images, 0 KB saveable
REVIEW
4 images, 0 KB saveable
Warning::
https://zenwriting.net/features/noun_branding_1885... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://zenwriting.net/features/noun_The%20Process... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://zenwriting.net/features/noun_3d%20modeling... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
4 images 16 KB
0 oversized -0 KB
4 legacy format
3 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

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

A+
Page Weight Budget
126 KB transferred, 12 requests
PASS
126 KB transferred, 12 requests
Info::
Page weighs 267 KB (126 KB transferred)
Info::
12 HTTP requests
Info::
Estimated 0.03 g CO2 per page load
126 KB / 2.4 MB budget
126 KB transferred
12 requests
0.03 g CO2 per page load
Fonts 78.9 KiB 63%
CSS 18.0 KiB 14%
Images 16.4 KiB 13%
Other 8.7 KiB 7%
HTML 2.6 KiB 2%
JavaScript 1.5 KiB 1%
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+
JS Execution Cost
240ms total JS execution
PASS
240ms total JS execution
Info::
Unattributable: 130ms CPU time
Info::
https://zenwriting.net/: 110ms CPU time
Warning::
Third-party scripts: 130ms (54% of total)

Main Thread Breakdown

Other 50% Style & Layout 34% Script Evaluation 6% Parse HTML & CSS 5% Rendering 5%
ScriptTotalScriptingParse/CompileParty
Unattributable130ms5ms0ms3rd
https://zenwriting.net/110ms4ms0ms1st
A+
Font Loading
2 fonts (79 KB)
PASS
2 fonts (79 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

79 KB total

Render-blocking

0

of 2

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 FCP 3.1 s LCP 3.1 shttps://fonts.gstatic.com/s/lora/v37/0QIvMX1D_JOuMwr7I_FMl_E.woff20QIvMX1D_JOuMwr7I_FMl_E... https://fonts.gstatic.com/s/lora/v37/0QIvMX1D_JOuMwr7I_FMl_E.woff2 — 36.9 KiB — 80 ms — font-display: swaphttps://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2memvYaGs126MiZpBA-UvWbX... https://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2 — 42.0 KiB — 81 ms — font-display: swap
0QIvMX1D_JOuMwr7I_FMl_E... woff2 swap
Size 37 KB
Load time 80 ms
Start 282 ms
Risk FOUT — text flashes from fallback to web font
memvYaGs126MiZpBA-UvWbX... woff2 swap
Size 42 KB
Load time 81 ms
Start 282 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+
JS Bundles
2 scripts, 0 KB unused
PASS
2 scripts, 0 KB unused
0 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://zenwriting.net/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js1 KB—✓1st
https://zenwriting.net/js/scripts.min.bf1e1f7ae8e03db5f012356e825843facdff51c0a559cb0d27fe2bbe1db405c2.js0 KB—✓1st
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
A
Page Weight Inventory
12 resources · 126 KB · 0 KB savings available
PASS
12 resources · 126 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 126 KB
Warning::
3 third-party resources (64% of weight)
12 resources · 126.1 KiB · 3 third-party Within 1MB page-weight target
Font 63% · 78.9 KiB
Image 20% · 25.1 KiB
CSS 14% · 18.0 KiB
Document 2% · 2.6 KiB
JavaScript 1% · 1.5 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+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Network Waterfall
12 requests over 439ms
INFO
0 ms 1.0 s 2.0 s 3.0 s FCP 3.1 s LCP 3.1 shttps://zenwriting.net// https://zenwriting.net/ — 200 — 2.6 KiB — 83 ms — h2https://zenwriting.net/css/style.min.3e25e0d8b6702e00684d9a35cfc1f3461ff28f5139aa60ece211c234673b3fdd.css/css/style.min.3e25e0d8b6702e00684d... https://zenwriting.net/css/style.min.3e25e0d8b6702e00684d9a35cfc1f3461ff28f5139aa60ece211c234673b3fdd.css — 200 — 15.7 KiB — 67 ms — h2https://zenwriting.net/features/noun_branding_1885335.svg/features/noun_branding_1885335.svg https://zenwriting.net/features/noun_branding_1885335.svg — 200 — 1.6 KiB — 64 ms — h2https://zenwriting.net/features/noun_The%20Process_1885341.svg/features/noun_The%20Process_188534... https://zenwriting.net/features/noun_The%20Process_1885341.svg — 200 — 1.7 KiB — 62 ms — h2https://zenwriting.net/features/noun_3d%20modeling_1885342.svg/features/noun_3d%20modeling_188534... https://zenwriting.net/features/noun_3d%20modeling_1885342.svg — 200 — 2.0 KiB — 64 ms — h2https://zenwriting.net/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js/cdn-cgi/scripts/5c5dd728/cloudflar... https://zenwriting.net/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js — 200 — 1022 B — 19 ms — h2https://zenwriting.net/js/scripts.min.bf1e1f7ae8e03db5f012356e825843facdff51c0a559cb0d27fe2bbe1db405c2.js/js/scripts.min.bf1e1f7ae8e03db5f01... https://zenwriting.net/js/scripts.min.bf1e1f7ae8e03db5f012356e825843facdff51c0a559cb0d27fe2bbe1db405c2.js — 200 — 468 B — 63 ms — h2https://fonts.googleapis.com/css?family=Lora:400,700|Open+Sans:300,400,700fonts.googleapis.com/css?family=Lor... https://fonts.googleapis.com/css?family=Lora:400,700|Open+Sans:300,400,700 — 200 — 2.4 KiB — 96 ms — h2https://zenwriting.net/images/undraw_taking_notes_tjaf.svg/images/undraw_taking_notes_tjaf.sv... https://zenwriting.net/images/undraw_taking_notes_tjaf.svg — 200 — 11.2 KiB — 83 ms — h3https://fonts.gstatic.com/s/lora/v37/0QIvMX1D_JOuMwr7I_FMl_E.woff2fonts.gstatic.com/s/lora/v37/0QIvMX... https://fonts.gstatic.com/s/lora/v37/0QIvMX1D_JOuMwr7I_FMl_E.woff2 — 200 — 36.9 KiB — 80 ms — h3https://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2fonts.gstatic.com/s/opensans/v44/me... https://fonts.gstatic.com/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2 — 200 — 42.0 KiB — 81 ms — h3https://zenwriting.net/favicon.png/favicon.png https://zenwriting.net/favicon.png — 200 — 8.7 KiB — 68 ms — h3
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
54% of JavaScript execution is third-party
First-party Third-party 130ms · 0KB · $2/mo
Unattributable
Other
Optional
Execution 130ms
Transfer 0 KB
Monthly Cost $2/mo

54% 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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