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https://www.fly.io

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
74
GRADE
C
FIX
3
REVIEW
4
PASS
5
INFO
2

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

Mobile Desktop
80
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
96
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.
82
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.

581 ms

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

3.61 s

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

86 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.

598 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.

3.76 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
5 PASS 4 REVIEW 3 FIX
F
Page Weight Budget
Action
5.1 MB transferred, 47 requests
FIX
5.1 MB transferred, 47 requests
Critical::
Page weighs 8.1 MB (5.1 MB transferred)
Warning::
Images are 3.6 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 3.6 MB
Warning::
JavaScript is 1.1 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.1 MB
Info::
Fonts are 297 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 297 KB
Info::
47 HTTP requests
Info::
Estimated 1.1 g CO2 per page load
5.1 MB / 2.4 MB budget
5.1 MB transferred
47 requests
1.1 g CO2 per page load
Images 3.6 MiB 71%
JavaScript 1.1 MiB 21%
Fonts 297.5 KiB 6%
CSS 88.5 KiB 2%
HTML 43.9 KiB 1%
Other 4.7 KiB 0%
Other 3.6 KiB 0%
Other 573 B 0%
0 2.4 MB 4.9 MB
Over budget

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Why this matters

Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.

Source: web.dev

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

Subset fonts to include only used characters, or switch to system font stacks.

Why this matters

Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).

Source: web.dev font loading

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 (5.1 MiB of 5.1 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
D
JS Bundles
Action
7 scripts, 469 KB unused
FIX
7 scripts, 469 KB unused
Warning::
https://fly.io/phx/assets/js/app-8e481f8200d3ae950...: 164 KB unused (33%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://analytics.fly.io/gtag/js?id=G-EX6DMZ1DZV&c...: 114 KB unused (67%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://analytics.fly.io/gtag/js?id=G-EX6DMZ1DZV: 66 KB unused (39%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://analytics.fly.io/gtag/js?id=G-XXXXXXXXXX&c...: 63 KB unused (47%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://analytics.fly.io/gtm.js?id=GTM-M35Q2HRQ: 62 KB unused (52%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 469 KB
469 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://fly.io/phx/assets/js/app-8e481f8200d3ae9504da3cfa56ce2cfb.js?vsn=d496 KB164 KB (33%)✓3rd
https://analytics.fly.io/gtag/js?id=G-EX6DMZ1DZV&cx=c&gtm=4e6460h1&sign=00e7d94f87835bd67d5a86c22ddaad133a9c7e091e99fd5aa642e95638e78afe_20260407171 KB114 KB (67%)✓3rd
https://analytics.fly.io/gtag/js?id=G-EX6DMZ1DZV171 KB66 KB (39%)✓3rd
https://analytics.fly.io/gtag/js?id=G-XXXXXXXXXX&cx=c&gtm=4e6460h1&sign=00e7d94f87835bd67d5a86c22ddaad133a9c7e091e99fd5aa642e95638e78afe_20260407135 KB63 KB (47%)✓3rd
https://analytics.fly.io/gtm.js?id=GTM-M35Q2HRQ119 KB62 KB (52%)✓3rd
https://fly.io/js/events.js2 KB—✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-M35Q2HRQ&gtg_health=10 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

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
Image Optimization
Action
21 images, 0 KB saveable
REVIEW
21 images, 0 KB saveable
Warning::
https://fly.io/phx/images/hercules-34711b926fd005d... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/2-home-5715b50f553c9da93... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/4-home-84e15e7b8209179b4... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/5-home-83633deac598ae018... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/mercor-a7ffc13de45fe6eff... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/new-home-hero-017530e154... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/context-8058d9902ba3a54d... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/imbue-df3742d6d74199de3c... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/home-6-779aa35b5c66e1acf... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/cogram-f563a22679f9ec18b... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/beam-335997b863cd192251b... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/supabase-533b3ab7b5869d3... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/webhound-84942d3551221c7... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/autoscale3-db93aeaddd7d7... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/3-home-1e977867026ea5209... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/builderio-49040d5f48090f... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/mocha-f959a31e6ecf819b3e... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://fly.io/phx/images/reflex-215f5d3819c3bfef0... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
21 images 3.6 MB
0 oversized -0 KB
12 legacy format
18 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

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

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

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

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

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

C
JS Execution Cost
Action
1028ms total JS execution
REVIEW
1028ms total JS execution
Warning::
https://fly.io/: 389ms CPU time
Info::
Unattributable: 206ms CPU time
Info::
https://fly.io/phx/assets/js/app-8e481f8200d3ae950...: 182ms CPU time
Info::
https://analytics.fly.io/gtm.js?id=GTM-M35Q2HRQ: 135ms CPU time
Info::
https://analytics.fly.io/gtag/js?id=G-XXXXXXXXXX&c...: 66ms CPU time
Warning::
Third-party scripts: 1028ms (100% of total)

Main Thread Breakdown

Other 42% Script Evaluation 32% Script Parsing & Compilation 11% Style & Layout 9%
ScriptTotalScriptingParse/CompileParty
https://fly.io/389ms6ms1ms3rd
Unattributable206ms14ms0ms3rd
https://fly.io/phx/assets/js/app-8e481f8200d3ae9504da3cfa56ce2cfb.js?vsn=d182ms114ms61ms3rd
https://analytics.fly.io/gtm.js?id=GTM-M35Q2HRQ135ms120ms12ms3rd
https://analytics.fly.io/gtag/js?id=G-XXXXXXXXXX&cx=c&gtm=4e6460h1&sign=00e7d94f87835bd67d5a86c22ddaad133a9c7e091e99fd5aa642e95638e78afe_2026040766ms48ms13ms3rd
https://analytics.fly.io/gtag/js?id=G-EX6DMZ1DZV50ms24ms17ms3rd
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

B
HTTP Caching
max-age=0, private, must-revalidate
REVIEW
max-age=0, private, must-revalidate
Info::
Cache-Control header is set
Got: max-age=0, private, must-revalidate
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

max-age=0, private, must-revalidate

DirectiveValueMeaning
max-age0Cache for 0 seconds
private—Only browser cache, not CDN/proxy
must-revalidate—Must recheck with server after expiry
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
7 fonts (297 KB)
PASS
7 fonts (297 KB)
Info::
7 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

7

297 KB total

Render-blocking

0

of 7

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 581 ms LCP 3.6 shttps://fly.io/phx/ui/fonts/fricolage-grotesque.var.woff2fricolage-grotesque.var... https://fly.io/phx/ui/fonts/fricolage-grotesque.var.woff2 — 143.2 KiB — 0 ms — font-display: swaphttps://fly.io/phx/ui/fonts/mackinac-medium.woff2mackinac-medium.woff2 https://fly.io/phx/ui/fonts/mackinac-medium.woff2 — 25.2 KiB — 0 ms — font-display: swaphttps://fly.io/phx/ui/fonts/mackinac-medium-italic.woff2mackinac-medium-italic.... https://fly.io/phx/ui/fonts/mackinac-medium-italic.woff2 — 26.0 KiB — 0 ms — font-display: swaphttps://fly.io/phx/ui/fonts/mackinac-bold.woff2mackinac-bold.woff2 https://fly.io/phx/ui/fonts/mackinac-bold.woff2 — 26.1 KiB — 0 ms — font-display: swaphttps://fly.io/phx/ui/fonts/mackinac-bold-italic.woff2mackinac-bold-italic.woff2 https://fly.io/phx/ui/fonts/mackinac-bold-italic.woff2 — 26.2 KiB — 0 ms — font-display: swaphttps://fly.io/phx/ui/fonts/fragment-mono-regular.woff2fragment-mono-regular.w... https://fly.io/phx/ui/fonts/fragment-mono-regular.woff2 — 24.9 KiB — 0 ms — font-display: swaphttps://fly.io/phx/ui/fonts/fragment-mono-italic.woff2fragment-mono-italic.woff2 https://fly.io/phx/ui/fonts/fragment-mono-italic.woff2 — 25.8 KiB — 0 ms — font-display: swap
fricolage-grotesque.var... woff2 swap
Size 143 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
mackinac-medium.woff2 woff2 swap
Size 25 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
mackinac-medium-italic.... woff2 swap
Size 26 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
mackinac-bold.woff2 woff2 swap
Size 26 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
mackinac-bold-italic.woff2 woff2 swap
Size 26 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
fragment-mono-regular.w... woff2 swap
Size 25 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
fragment-mono-italic.woff2 woff2 swap
Size 26 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 ~72 KB and ~144 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
47 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
100% of JavaScript execution is third-party
First-party Third-party 1028ms · 963KB · $14/mo
fly.io
Other
Costly
Execution 389ms
Transfer 42 KB
Monthly Cost $5/mo
Unattributable
Other
Costly
Execution 206ms
Transfer 0 KB
Monthly Cost $3/mo
fly.io
Other
Optional
Execution 182ms
Transfer 496 KB
Unused 33%
Monthly Cost $2/mo
analytics.fly.io
Other
Optional
Execution 135ms
Transfer 119 KB
Unused 52%
Monthly Cost $2/mo
analytics.fly.io
Other
Optional
Execution 66ms
Transfer 135 KB
Unused 47%
Monthly Cost $1/mo
analytics.fly.io
Other
Optional
Execution 50ms
Transfer 171 KB
Unused 39%
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • fly.io adds 389ms and costs ~$5/month
  • Unattributable adds 206ms and costs ~$3/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

fly.io takes 389ms 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

Unattributable takes 206ms 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

52% of analytics.fly.io'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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