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https://Dylankotzer.com

Performance

· 22 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
90
GRADE
A
FIX
1
REVIEW
4
PASS
14
INFO
3

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.
87
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.

968 ms

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

1.81 s

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

135 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.

1.23 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.

1.86 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
22
14 PASS 4 REVIEW 1 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 (958.8 KiB of 959.4 KiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
C
JS Bundles
Action
2 scripts, 195 KB unused
REVIEW
2 scripts, 195 KB unused
Warning::
https://www.dylankotzer.com/static/js/main.f9e0e4e...: 130 KB unused (27%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-W4J4...: 65 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 195 KB
195 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.dylankotzer.com/static/js/main.f9e0e4ec.js484 KB130 KB (27%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-W4J4LY449S156 KB65 KB (42%)✓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
Compression Algorithm
Action
Main response served uncompressed
REVIEW
Main response served uncompressed
Info::
Main HTML response has no Content-Encoding (uncompressed)
The main HTML document is served without compression. The Text Compression section above lists the broader picture; for the main response specifically, even gzip would shave ~70-80% off most text payloads.
B
Server-Timing Observability
No Server-Timing header found
REVIEW
No Server-Timing header found
Info::
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.
B
HTTP Caching
public, max-age=0, must-revalidate
REVIEW
public, max-age=0, must-revalidate
Info::
Cache-Control header is set
Got: public, max-age=0, must-revalidate
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

public, max-age=0, must-revalidate

DirectiveValueMeaning
public—Any cache may store this response
max-age0Cache for 0 seconds
must-revalidate—Must recheck with server after expiry
A
Page Weight Budget
959 KB transferred, 13 requests
PASS
959 KB transferred, 13 requests
Info::
Page weighs 2.5 MB (959 KB transferred)
Warning::
JavaScript is 640 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 640 KB
Info::
13 HTTP requests
Info::
Estimated 0.20 g CO2 per page load
959 KB / 2.4 MB budget
959 KB transferred
13 requests
0.20 g CO2 per page load
JavaScript 639.6 KiB 67%
Images 269.2 KiB 28%
Fonts 36.7 KiB 4%
Other 6.4 KiB 1%
CSS 5.0 KiB 1%
HTML 1.2 KiB 0%
Other 926 B 0%
Other 552 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+
Image Optimization
1 images, 0 KB saveable
PASS
1 images, 0 KB saveable
Info::
All images are well-optimized
1 images 269 KB
0 oversized -0 KB
1 legacy format
0 missing dimensions CLS risk
A+
JS Execution Cost
437ms total JS execution
PASS
437ms total JS execution
Warning::
https://www.dylankotzer.com/static/js/main.f9e0e4e...: 332ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-W4J4...: 54ms CPU time
Info::
https://www.dylankotzer.com/: 51ms CPU time
Warning::
Third-party scripts: 437ms (100% of total)

Main Thread Breakdown

Script Evaluation 66% Other 15% Style & Layout 7% Script Parsing & Compilation 7%
ScriptTotalScriptingParse/CompileParty
https://www.dylankotzer.com/static/js/main.f9e0e4ec.js332ms273ms26ms3rd
https://www.googletagmanager.com/gtag/js?id=G-W4J4LY449S54ms46ms8ms3rd
https://www.dylankotzer.com/51ms1ms0ms3rd
A+
Font Loading
1 fonts (37 KB)
PASS
1 fonts (37 KB)
Info::
1 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

1

37 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 500 ms 1.0 s 1.5 s FCP 968 ms LCP 1.8 shttps://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2KFO7CnqEu92Fr1ME7kSn66a... https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2 — 36.7 KiB — 53 ms — font-display: swap
KFO7CnqEu92Fr1ME7kSn66a... woff2 swap
Size 37 KB
Load time 53 ms
Start 572 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
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
A+
HTTP/3 (QUIC)
HTTP/3 advertised via Alt-Svc
PASS
HTTP/3 advertised via Alt-Svc
Info::
HTTP/3 (QUIC) is supported
First-load mobile users on cellular networks see meaningful latency improvements with HTTP/3. The QUIC transport collapses TLS + TCP handshakes into one and recovers faster from packet loss.
A+
LCP Image Preload
LCP preload audit not available
PASS
LCP preload audit not available
Info::
LCP image preload audit not available for this scan
A+
Main HTML Cache-Control
Main HTML max-age=0 (≤ 5min) is appropriate
PASS
Main HTML max-age=0 (≤ 5min) is appropriate
Info::
Main HTML max-age=0 (≤ 5min) is appropriate
Got: public, max-age=0, must-revalidate
A+
Server Response Intelligence
1 server-response signal(s) detected
PASS
1 server-response signal(s) detected
Info::
No `ETag` or `Last-Modified` -- conditional GET not supported
Without either header, browsers can't issue conditional GETs and refresh always re-downloads the full response body even when nothing changed. Add `ETag: "<hash>"` (or `Last-Modified: <date>`) on cacheable responses; the server returns 304 Not Modified when the client's cached copy is still valid, saving bandwidth.
A
Page Weight Inventory
13 resources · 959 KB · 195 KB savings available
PASS
13 resources · 959 KB · 195 KB savings available
Info::
Within 1MB page-weight target
Got: 959 KB
Info::
~195 KB of savings available
Warning::
12 third-party resources (100% of weight)
Info::
2 resources over 200KB
13 resources · 959.4 KiB · 12 third-party Within 1MB page-weight target
JavaScript 67% · 639.6 KiB
Image 29% · 275.0 KiB
Font 4% · 36.7 KiB
CSS 1% · 5.0 KiB
Document 0% · 1.7 KiB
Other 0% · 1.4 KiB

~195.4 KiB of savings available

Remove unused JavaScript: 195.4 KiB
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
13 requests over 748ms
INFO
0 ms 500 ms 1.0 s 1.5 s FCP 968 ms LCP 1.8 shttps://dylankotzer.com// https://dylankotzer.com/ — 308 — 600 B — 71 ms — h3https://www.dylankotzer.com/www.dylankotzer.com/ https://www.dylankotzer.com/ — 200 — 1.2 KiB — 46 ms — h3https://fonts.googleapis.com/css?family=Roboto:300,400,500,700&display=swapfonts.googleapis.com/css?family=Rob... https://fonts.googleapis.com/css?family=Roboto:300,400,500,700&display=swap — 200 — 2.2 KiB — 144 ms — h2https://fonts.googleapis.com/icon?family=Material+Iconsfonts.googleapis.com/icon?family=Ma... https://fonts.googleapis.com/icon?family=Material+Icons — 200 — 446 B — 150 ms — h2https://www.dylankotzer.com/style.csswww.dylankotzer.com/style.css https://www.dylankotzer.com/style.css — 200 — 2.3 KiB — 56 ms — h3https://www.dylankotzer.com/static/js/main.f9e0e4ec.jswww.dylankotzer.com/static/js/main.... https://www.dylankotzer.com/static/js/main.f9e0e4ec.js — 200 — 483.9 KiB — 134 ms — h3https://www.googletagmanager.com/gtag/js?id=G-W4J4LY449Swww.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=G-W4J4LY449S — 200 — 155.6 KiB — 244 ms — h2https://www.dylankotzer.com/manifest.jsonwww.dylankotzer.com/manifest.json https://www.dylankotzer.com/manifest.json — 200 — 926 B — 57 ms — h3https://www.dylankotzer.com/favicon.pngwww.dylankotzer.com/favicon.png https://www.dylankotzer.com/favicon.png — 200 — 269.2 KiB — 37 ms — h3https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2fonts.gstatic.com/s/roboto/v51/KFO7... https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2 — 200 — 36.7 KiB — 53 ms — h3https://region1.google-analytics.com/g/collect?v=2&tid=G-W4J4LY449S&gtm=45je6562h1v895653871za200zd895653871&_p=1778411190766&gcd=13l3l3l2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1004268573.1778411191&frm=0&pscdl=noapi&rcb=4&sr=800x600&uaa=x86&uab=64&uafvl=Not%252FA)Brand%3B99.0.0.0%7CChromium%3B148.0.7778.96&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115616986~115938465~115938468~118463261&sid=1778411191&sct=1&seg=0&dl=https%3A%2F%2Fwww.dylankotzer.com%2F&dt=Dylan&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=680region1.google-analytics.com/g/coll... https://region1.google-analytics.com/g/collect?v=2&tid=G-W4J4LY449S&gtm=45je6562h1v895653871za200zd895653871&_p=1778411190766&gcd=13l3l3l2l1l1&npa=1&dma_cps=a&dma=1&are=1&cid=1004268573.1778411191&frm=0&pscdl=noapi&rcb=4&sr=800x600&uaa=x86&uab=64&uafvl=Not%252FA)Brand%3B99.0.0.0%7CChromium%3B148.0.7778.96&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115616986~115938465~115938468~118463261&sid=1778411191&sct=1&seg=0&dl=https%3A%2F%2Fwww.dylankotzer.com%2F&dt=Dylan&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=680 — 204 — 552 B — 67 ms — h2https://www.dylankotzer.com/favicon.pngwww.dylankotzer.com/favicon.png https://www.dylankotzer.com/favicon.png — 200 — 0 B — 4 ms — h3https://www.dylankotzer.com/logo192.pngwww.dylankotzer.com/logo192.png https://www.dylankotzer.com/logo192.png — 200 — 5.8 KiB — 32 ms — h3
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 437ms · 641KB · $6/mo
www.dylankotzer.com
Other
Costly
Execution 332ms
Transfer 484 KB
Unused 27%
Monthly Cost $4/mo
Google Tag Manager
Tag Manager
Optional
Execution 54ms
Transfer 156 KB
Unused 42%
Monthly Cost $1/mo
www.dylankotzer.com
Other
Optional
Execution 51ms
Transfer 1 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • www.dylankotzer.com adds 332ms and costs ~$4/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

www.dylankotzer.com takes 332ms 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

How third-party costs are calculated

Image Optimization
1 images, 269 KB total, 265 KB wasted
INFO

Image Optimization Audit

Total Images

1

Total Size

269 KB

Oversized

1

Wasted

265 KB

1 missing dimensions 1 missing lazy loading
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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