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Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
91
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.
90
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
92
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
36
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.

963 ms

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

1.47 s

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

483 ms

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

0.003

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

963 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.

3.25 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
81% third-party, 0 ms blocking
FIX
81% third-party, 0 ms blocking
Warning::
Third-party code accounts for 81% of page weight (380.1 KiB of 468.6 KiB)
Info::
Third-party blocking time is low (0 ms)
19%
81%
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
JS Execution Cost
Action
1115ms total JS execution
REVIEW
1115ms total JS execution
Warning::
https://codecademy.com/cdn-cgi/challenge-platform/...: 880ms CPU time
Info::
Unattributable: 135ms CPU time
Info::
https://codecademy.com/: 100ms CPU time
Info::
Third-party scripts: 135ms (12% of total)

Main Thread Breakdown

Script Evaluation 77% Other 14% Style & Layout 3%
ScriptTotalScriptingParse/CompileParty
https://codecademy.com/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=9eceb6247b040274880ms844ms16ms1st
Unattributable135ms4ms0ms3rd
https://codecademy.com/100ms16ms1ms1st
A+
Page Weight Budget
469 KB transferred, 22 requests
PASS
469 KB transferred, 22 requests
Info::
Page weighs 886 KB (469 KB transferred)
Info::
22 HTTP requests
Info::
Estimated 0.10 g CO2 per page load
469 KB / 2.4 MB budget
469 KB transferred
22 requests
0.10 g CO2 per page load
Other 279.4 KiB 60%
HTML 97.5 KiB 21%
JavaScript 89.0 KiB 19%
Other 1.7 KiB 0%
Images 907 B 0%
Other 131 B 0%
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
Image Optimization
3 images, 0 KB saveable
PASS
3 images, 0 KB saveable
Info::
All images are well-optimized
3 images 1 KB
0 oversized -0 KB
2 legacy format
0 missing dimensions CLS risk
A+
Font Loading
No web fonts (system fonts)
PASS
No web fonts (system fonts)
Info::
No web fonts loaded — system fonts are fastest
No web fonts loaded — system fonts are optimal.
A+
JS Bundles
10 scripts, 0 KB unused
PASS
10 scripts, 0 KB unused
0 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://codecademy.com/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=9eceb6247b04027472 KB—✓1st
blob:https://codecademy.com/4ae7f4fd-631f-4136-9edc-9827dda5fb4a0 KB—✓3rd
https://challenges.cloudflare.com/turnstile/v0/g/b0a7532ac8ec/api.js?onload=cFyL2&render=explicit17 KB—✓3rd
blob:https://codecademy.com/ab17de91-7c10-49fa-80be-239979d1d66c-0 KB—✓3rd
blob:https://challenges.cloudflare.com/3dace7bb-52c8-4e35-95dc-ec1a040bab810 KB—✓3rd
blob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6-0 KB—✓3rd
blob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6-0 KB—✓3rd
blob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6-0 KB—✓3rd
blob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce60 KB—✓3rd
blob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6-0 KB—✓3rd
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
22 resources · 469 KB · 0 KB savings available
PASS
22 resources · 469 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 469 KB
Warning::
16 third-party resources (81% of weight)
Info::
1 resources over 200KB
22 resources · 468.6 KiB · 16 third-party Within 1MB page-weight target
Other 60% · 281.2 KiB
Document 21% · 97.5 KiB
JavaScript 19% · 89.0 KiB
Image 0% · 907 B
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
22 requests over 2622ms
INFO
0 ms 500 ms 1.0 s 1.5 s 2.0 s 2.5 s FCP 963 ms LCP 1.5 shttps://codecademy.com// https://codecademy.com/ — 307 — 64 B — 67 ms — http/1.1https://codecademy.com// https://codecademy.com/ — 403 — 3.3 KiB — 22 ms — h2https://codecademy.com/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=9eceb6247b040274/cdn-cgi/challenge-platform/h/g/orc... https://codecademy.com/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=9eceb6247b040274 — 200 — 71.7 KiB — 45 ms — h2blob:https://codecademy.com/4ae7f4fd-631f-4136-9edc-9827dda5fb4acodecademy.com/4ae7f4fd-631f-4136-9... blob:https://codecademy.com/4ae7f4fd-631f-4136-9edc-9827dda5fb4a — -1 — 0 B — 0 ms — https://challenges.cloudflare.com/turnstile/v0/g/b0a7532ac8ec/api.js?onload=cFyL2&render=explicitchallenges.cloudflare.com/turnstile... https://challenges.cloudflare.com/turnstile/v0/g/b0a7532ac8ec/api.js?onload=cFyL2&render=explicit — 200 — 17.4 KiB — 100 ms — h3https://codecademy.com/favicon.ico/favicon.ico https://codecademy.com/favicon.ico — 301 — 67 B — 25 ms — h2https://www.codecademy.com/favicon.icowww.codecademy.com/favicon.ico https://www.codecademy.com/favicon.ico — -1 — 0 B — 92 ms — https://codecademy.com/cdn-cgi/challenge-platform/h/g/flow/ov1/2101963723:1776294714:hxPki-uH3yb6z1oFr5P0pT-fewCq9YZDZcKtkGTF5W0/9eceb6247b040274/NXR..U.76gs4slyBDeq0MM9x_4A5Gmf_jM1KxoCx.3U-1776295547-1.2.1.1-FeVkf.2k3jScCEbowkiiwwO4dLcuwhYjLX70z_cNJxWE__pJe6SoWH08AFT14325/cdn-cgi/challenge-platform/h/g/flo... https://codecademy.com/cdn-cgi/challenge-platform/h/g/flow/ov1/2101963723:1776294714:hxPki-uH3yb6z1oFr5P0pT-fewCq9YZDZcKtkGTF5W0/9eceb6247b040274/NXR..U.76gs4slyBDeq0MM9x_4A5Gmf_jM1KxoCx.3U-1776295547-1.2.1.1-FeVkf.2k3jScCEbowkiiwwO4dLcuwhYjLX70z_cNJxWE__pJe6SoWH08AFT14325 — 200 — 13.4 KiB — 37 ms — h2https://codecademy.com/favicon.ico/favicon.ico https://codecademy.com/favicon.ico — 301 — 0 B — 1 ms — h2https://www.codecademy.com/favicon.icowww.codecademy.com/favicon.ico https://www.codecademy.com/favicon.ico — -1 — 0 B — 54 ms — blob:https://codecademy.com/ab17de91-7c10-49fa-80be-239979d1d66ccodecademy.com/ab17de91-7c10-49fa-8... blob:https://codecademy.com/ab17de91-7c10-49fa-80be-239979d1d66c — 200 — -1 B — 31 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/turnstile/f/ov2/av0/rch/4l0yz/0x4AAAAAAADnPIDROrmt1Wwj/light/fbE/new/normal?lang=autochallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/turnstile/f/ov2/av0/rch/4l0yz/0x4AAAAAAADnPIDROrmt1Wwj/light/fbE/new/normal?lang=auto — 200 — 94.2 KiB — 105 ms — h3https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/cmg/1challenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/cmg/1 — 200 — 208 B — 30 ms — h3blob:https://challenges.cloudflare.com/3dace7bb-52c8-4e35-95dc-ec1a040bab81challenges.cloudflare.com/3dace7bb-... blob:https://challenges.cloudflare.com/3dace7bb-52c8-4e35-95dc-ec1a040bab81 — -1 — 0 B — 0 ms — https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/flow/ov1/1250041109:1776294715:G-MwTZZkbZJhxmTQ3ZhFFu11zimeqnMrRRnrtJ1Os6E/9eceb626c9d8d716/Kt2MzY4xF2rdU6TqsCNK8BWQsSwQP20BKSoefWHGsfk-1776295547-1.2.1.1-y6hJipkMwtVVvJVGOiAkRnFwt6nZNeMjMp8IvkyULOXJvaU9H.vIxMnUTdWQmWMychallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/flow/ov1/1250041109:1776294715:G-MwTZZkbZJhxmTQ3ZhFFu11zimeqnMrRRnrtJ1Os6E/9eceb626c9d8d716/Kt2MzY4xF2rdU6TqsCNK8BWQsSwQP20BKSoefWHGsfk-1776295547-1.2.1.1-y6hJipkMwtVVvJVGOiAkRnFwt6nZNeMjMp8IvkyULOXJvaU9H.vIxMnUTdWQmWMy — 200 — 266.0 KiB — 161 ms — h3blob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6challenges.cloudflare.com/cdadd2a1-... blob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6 — 200 — -1 B — 60 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/d/9eceb626c9d8d716/1776295548265/am6zBxfsRioUw9zchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/d/9eceb626c9d8d716/1776295548265/am6zBxfsRioUw9z — 200 — 699 B — 21 ms — h3blob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6challenges.cloudflare.com/cdadd2a1-... blob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6 — 200 — -1 B — 28 ms — blobblob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6challenges.cloudflare.com/cdadd2a1-... blob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6 — 200 — -1 B — 28 ms — blobblob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6challenges.cloudflare.com/cdadd2a1-... blob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6 — -1 — 0 B — 0 ms — https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/pat/9eceb626c9d8d716/1776295548267/7344b2dabf50ae2d25fe512a283e3b83a68e0d615ae8e253410692317530d4fc/Vvvlmtxjxh4H9jOchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/pat/9eceb626c9d8d716/1776295548267/7344b2dabf50ae2d25fe512a283e3b83a68e0d615ae8e253410692317530d4fc/Vvvlmtxjxh4H9jO — 401 — 1.7 KiB — 21 ms — h3blob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6challenges.cloudflare.com/cdadd2a1-... blob:https://challenges.cloudflare.com/cdadd2a1-16d0-403a-8822-6a5e3b0ebce6 — 200 — -1 B — 11 ms — blob
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
12% of JavaScript execution is third-party
First-party Third-party 135ms · 0KB · $2/mo
Unattributable
Other
Optional
Execution 135ms
Transfer 0 KB
Monthly Cost $2/mo

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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