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Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
84
GRADE
B
FIX
3
REVIEW
2
PASS
9
INFO
2

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

Mobile Desktop
56
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
92
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.
92
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.

6.98 s

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

7.92 s

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

194 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.

6.98 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.

7.92 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
16
9 PASS 2 REVIEW 3 FIX
D
Page Weight Budget
Action
2.3 MB transferred, 46 requests
FIX
2.3 MB transferred, 46 requests
Info::
Page weighs 2.8 MB (2.3 MB transferred)
Warning::
Images are 1.2 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 1.2 MB
Info::
Fonts are 970 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 970 KB
Info::
46 HTTP requests
Info::
Estimated 0.48 g CO2 per page load
2.3 MB / 2.4 MB budget
2.3 MB transferred
46 requests
0.48 g CO2 per page load
Images 1.2 MiB 52%
Fonts 970.3 KiB 42%
JavaScript 77.8 KiB 3%
CSS 29.7 KiB 1%
HTML 19.8 KiB 1%
Other 7.8 KiB 0%
Other 426 B 0%
Other 223 B 0%
0 2.4 MB 4.9 MB
Approaching limit

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

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 (2.3 MiB of 2.3 MiB)
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.

C
Image Optimization
Action
22 images, 0 KB saveable
REVIEW
22 images, 0 KB saveable
Warning::
https://ocaml.org/_/NjBkMWJkNDgzZjAwMTQ4MjlmYjUyN2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/ZWVmZmU2MzczN2FjZTk2OGE5MDViNT... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/OGI2M2JmY2NkYzQ0NzNjNTRhNGQ3ZD... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/OGNjZjBhMjg4MjQ2NDlmMWNiODE0ZG... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/MjcxNDQ0ZThiMDY2NjA0Y2ExNWRmZT... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/ZTM4NWExMjJiZjAwZjEzMWY5MTNjYj... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/MzEyZWI2NmFiMWY4ZGEwZmRkMDcxYT... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/ZDkzZDYxMDlmMmZjMTdhNjdhNTBhMT... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/ZGVjYTI0ZGJjNzYzZmRlZGQ3OWI0Mj... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/YjEyNTk1YjM2ZmIyMWFlNGFlYTM2MT... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/Mzc0OTY1YzIzYWI2YmJkMzVlNGUzNT... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/YTgwYjYyMzhlYzQwNTRhNmRlMzJkNT... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/YzA5ZWY4OTQ5Mjc1NjA4MmQ3NzAyNT... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/MDBjN2M4YjIxY2Y1YWExZWE3Njk4M2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/NDBkZDQ2N2U3Y2VmM2I1NWZkNTk0NW... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/ODdlNDViNTBkNGY4YjFiNzBkY2E2ZT... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://ocaml.org/_/ZGJiYTQ0NTA0MjQyMDIzMGU2YTJjZD... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
22 images 1.2 MB
0 oversized -0 KB
22 legacy format
17 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

C
JS Execution Cost
Action
1078ms total JS execution
REVIEW
1078ms total JS execution
Warning::
https://ocaml.org/_/ZDJiMGNkNGMzMjBlYjNmZGUxNTMxOT...: 445ms CPU time
Warning::
Unattributable: 328ms CPU time
Info::
https://ocaml.org/: 238ms CPU time
Info::
https://ocaml.org/_/NGI1NjQzZjdkODY0MTY2MmViNThhM2...: 67ms CPU time
Warning::
Third-party scripts: 1078ms (100% of total)

Main Thread Breakdown

Style & Layout 44% Other 30% Script Evaluation 17% Rendering 4%
ScriptTotalScriptingParse/CompileParty
https://ocaml.org/_/ZDJiMGNkNGMzMjBlYjNmZGUxNTMxOTAyNjA0MDU2N2Q/vendors/swiper-bundle.min.js445ms29ms12ms3rd
Unattributable328ms6ms0ms3rd
https://ocaml.org/238ms74ms3ms3rd
https://ocaml.org/_/NGI1NjQzZjdkODY0MTY2MmViNThhM2VlZTYwMDk3NTI/vendors/alpine.min.js67ms61ms5ms3rd
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
10 fonts (970 KB)
PASS
10 fonts (970 KB)
Info::
10 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

10

970 KB total

Render-blocking

0

of 10

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 FCP 7.0 s LCP 7.9 shttps://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-Regular.woff2?v=3.19Inter-Regular.woff2 https://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-Regular.woff2?v=3.19 — 97.8 KiB — 0 ms — font-display: swaphttps://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-Bold.woff2?v=3.19Inter-Bold.woff2 https://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-Bold.woff2?v=3.19 — 105.0 KiB — 0 ms — font-display: swaphttps://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-SemiBold.woff2?v=3.19Inter-SemiBold.woff2 https://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-SemiBold.woff2?v=3.19 — 104.9 KiB — 0 ms — font-display: swaphttps://ocaml.org/_/YjM3OGY4YzIwN2E2ZmUxZTczOWVkNDQwZWRhMDU0MGM/vendors/font-files/RobotoMono-Regular.woff2RobotoMono-Regular.woff2 https://ocaml.org/_/YjM3OGY4YzIwN2E2ZmUxZTczOWVkNDQwZWRhMDU0MGM/vendors/font-files/RobotoMono-Regular.woff2 — 37.4 KiB — 0 ms — font-display: swaphttps://ocaml.org/_/YjM3OGY4YzIwN2E2ZmUxZTczOWVkNDQwZWRhMDU0MGM/vendors/font-files/RobotoMono-Italic.woff2RobotoMono-Italic.woff2 https://ocaml.org/_/YjM3OGY4YzIwN2E2ZmUxZTczOWVkNDQwZWRhMDU0MGM/vendors/font-files/RobotoMono-Italic.woff2 — 40.8 KiB — 0 ms — font-display: swaphttps://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-BoldItalic.woff2?v=3.19Inter-BoldItalic.woff2 https://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-BoldItalic.woff2?v=3.19 — 110.6 KiB — 0 ms — font-display: swaphttps://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-Italic.woff2?v=3.19Inter-Italic.woff2 https://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-Italic.woff2?v=3.19 — 105.6 KiB — 0 ms — font-display: swaphttps://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-Medium.woff2?v=3.19Inter-Medium.woff2 https://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-Medium.woff2?v=3.19 — 104.8 KiB — 0 ms — font-display: swaphttps://ocaml.org/_/YjM3OGY4YzIwN2E2ZmUxZTczOWVkNDQwZWRhMDU0MGM/vendors/font-files/RobotoMono-SemiBold.woff2RobotoMono-SemiBold.woff2 https://ocaml.org/_/YjM3OGY4YzIwN2E2ZmUxZTczOWVkNDQwZWRhMDU0MGM/vendors/font-files/RobotoMono-SemiBold.woff2 — 38.3 KiB — 0 ms — font-display: swaphttps://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-roman.var.woff2?v=3.19Inter-roman.var.woff2 https://ocaml.org/_/NmFjYjY5ZmIxYWRhMWQxMTQxODM4ZDEwYTgwMDcwNmI/vendors/font-files/Inter-roman.var.woff2?v=3.19 — 225.0 KiB — 0 ms — font-display: swap
Inter-Regular.woff2 woff2 swap
Size 98 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Inter-Bold.woff2 woff2 swap
Size 105 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
Inter-SemiBold.woff2 woff2 swap
Size 105 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
RobotoMono-Regular.woff2 woff2 swap
Size 37 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
RobotoMono-Italic.woff2 woff2 swap
Size 41 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Inter-BoldItalic.woff2 woff2 swap
Size 111 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
Inter-Italic.woff2 woff2 swap
Size 106 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
Inter-Medium.woff2 woff2 swap
Size 105 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
RobotoMono-SemiBold.woff2 woff2 swap
Size 38 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Inter-roman.var.woff2 woff2 swap
Size 225 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
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 ~378 KB and ~756 ms

A+
JS Bundles
5 scripts, 25 KB unused
PASS
5 scripts, 25 KB unused
Warning::
https://ocaml.org/_/ZDJiMGNkNGMzMjBlYjNmZGUxNTMxOT...: 25 KB unused (59%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 25 KB
25 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://ocaml.org/_/ZDJiMGNkNGMzMjBlYjNmZGUxNTMxOTAyNjA0MDU2N2Q/vendors/swiper-bundle.min.js42 KB25 KB (59%)✓3rd
https://ocaml.org/_/OWYyZDQyZjg4MTFlNWEzZjE4ZGY0YWM0OTU1NGEzYTI/vendors/alpine-clipboard.js1 KB—✓3rd
https://ocaml.org/_/NGI1NjQzZjdkODY0MTY2MmViNThhM2VlZTYwMDk3NTI/vendors/alpine.min.js17 KB—✓3rd
https://ocaml.org/_/YTNhODI2Yzg0Yzk4M2ZiNDcxYmRiYzdhY2FiN2Y0OWQ/vendors/htmx.min.js17 KB—✓3rd
https://plausible.ci.dev/js/script.js2 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

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+
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: Scaleway

Network Waterfall
46 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 1078ms · 79KB · €12/mo
ocaml.org
Other
Costly
Execution 445ms
Transfer 42 KB
Unused 59%
Monthly Cost €5/mo
Unattributable
Other
Costly
Execution 328ms
Transfer 0 KB
Monthly Cost €4/mo
ocaml.org
Other
Costly
Execution 238ms
Transfer 20 KB
Monthly Cost €3/mo
ocaml.org
Other
Optional
Execution 67ms
Transfer 17 KB
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • ocaml.org adds 445ms and costs ~€5/month
  • Unattributable adds 328ms and costs ~€4/month
  • ocaml.org adds 238ms 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

ocaml.org takes 445ms 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

59% of ocaml.org'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

Unattributable takes 328ms 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

ocaml.org takes 238ms 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

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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