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Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
91
GRADE
A
FIX
2
REVIEW
0
PASS
11
INFO
1

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

Mobile Desktop
100
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.

288 ms

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

822 ms

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

13 ms

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

0.001

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

378 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.

822 ms

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
11 PASS 2 FIX
D
Third-Party Impact
Action
82% third-party, 0 ms blocking
FIX
82% third-party, 0 ms blocking
Warning::
Third-party code accounts for 82% of page weight (393.7 KiB of 482.2 KiB)
Info::
Third-party blocking time is low (0 ms)
18%
82%
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.

A+
Page Weight Budget
482 KB transferred, 21 requests
PASS
482 KB transferred, 21 requests
Info::
Page weighs 905 KB (482 KB transferred)
Info::
21 HTTP requests
Info::
Estimated 0.10 g CO2 per page load
482 KB / 2.4 MB budget
482 KB transferred
21 requests
0.10 g CO2 per page load
Other 288.2 KiB 60%
HTML 97.8 KiB 20%
JavaScript 89.1 KiB 18%
Images 5.3 KiB 1%
Other 1.7 KiB 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 5 KB
0 oversized -0 KB
2 legacy format
0 missing dimensions CLS risk
A+
JS Execution Cost
233ms total JS execution
PASS
233ms total JS execution
Info::
https://codecademy.com/cdn-cgi/challenge-platform/...: 233ms CPU time

Main Thread Breakdown

Script Evaluation 79% Other 11% Garbage Collection 3% Style & Layout 3%
ScriptTotalScriptingParse/CompileParty
https://codecademy.com/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=9eceb68f3a52ae88233ms216ms4ms1st
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
8 scripts, 0 KB unused
PASS
8 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=9eceb68f3a52ae8872 KB—✓1st
blob:https://codecademy.com/db675450-cf8c-4fe5-946f-5819e12d763f0 KB—✓3rd
https://challenges.cloudflare.com/turnstile/v0/g/b0a7532ac8ec/api.js?onload=cFyL2&render=explicit17 KB—✓3rd
blob:https://codecademy.com/917fa632-ce97-4ebe-aa5a-ac3c2c7792ca-0 KB—✓3rd
blob:https://challenges.cloudflare.com/8ea283ac-c2e2-45c6-9902-a54c15f8c68a0 KB—✓3rd
blob:https://challenges.cloudflare.com/17219a07-d10f-437e-84cd-ee5d43cbfa11-0 KB—✓3rd
blob:https://challenges.cloudflare.com/17219a07-d10f-437e-84cd-ee5d43cbfa11-0 KB—✓3rd
blob:https://challenges.cloudflare.com/3c0e0659-7905-46c7-9b97-33a51cf1aee0-0 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
21 resources · 482 KB · 0 KB savings available
PASS
21 resources · 482 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 482 KB
Warning::
15 third-party resources (82% of weight)
Info::
1 resources over 200KB
21 resources · 482.2 KiB · 15 third-party Within 1MB page-weight target
Other 60% · 290.0 KiB
Document 20% · 97.8 KiB
JavaScript 18% · 89.1 KiB
Image 1% · 5.3 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
21 requests over 2308ms
INFO
0 ms 500 ms 1.0 s 1.5 s 2.0 s FCP 288 ms LCP 822 mshttps://codecademy.com// https://codecademy.com/ — 307 — 64 B — 62 ms — http/1.1https://codecademy.com// https://codecademy.com/ — 403 — 3.3 KiB — 21 ms — h2https://codecademy.com/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=9eceb68f3a52ae88/cdn-cgi/challenge-platform/h/g/orc... https://codecademy.com/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=9eceb68f3a52ae88 — 200 — 71.7 KiB — 42 ms — h2blob:https://codecademy.com/db675450-cf8c-4fe5-946f-5819e12d763fcodecademy.com/db675450-cf8c-4fe5-9... blob:https://codecademy.com/db675450-cf8c-4fe5-946f-5819e12d763f — -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 — 62 ms — h3https://codecademy.com/favicon.ico/favicon.ico https://codecademy.com/favicon.ico — 301 — 67 B — 23 ms — h2https://www.codecademy.com/favicon.icowww.codecademy.com/favicon.ico https://www.codecademy.com/favicon.ico — -1 — 0 B — 102 ms — https://codecademy.com/cdn-cgi/challenge-platform/h/g/flow/ov1/2101963723:1776294714:hxPki-uH3yb6z1oFr5P0pT-fewCq9YZDZcKtkGTF5W0/9eceb68f3a52ae88/Rha97uYTsXVWjGFMPCuiiC_k.5TJjR6hGltwO6r4x5Y-1776295564-1.2.1.1-15a6B8U.yaUwiEStFo0uumnNmjQTW9PW97EI9hgFUh21s5knUR3MoqibAlsZOTP0/cdn-cgi/challenge-platform/h/g/flo... https://codecademy.com/cdn-cgi/challenge-platform/h/g/flow/ov1/2101963723:1776294714:hxPki-uH3yb6z1oFr5P0pT-fewCq9YZDZcKtkGTF5W0/9eceb68f3a52ae88/Rha97uYTsXVWjGFMPCuiiC_k.5TJjR6hGltwO6r4x5Y-1776295564-1.2.1.1-15a6B8U.yaUwiEStFo0uumnNmjQTW9PW97EI9hgFUh21s5knUR3MoqibAlsZOTP0 — 200 — 13.4 KiB — 30 ms — h2https://codecademy.com/favicon.ico/favicon.ico https://codecademy.com/favicon.ico — 301 — 0 B — 0 ms — h2https://www.codecademy.com/favicon.icowww.codecademy.com/favicon.ico https://www.codecademy.com/favicon.ico — -1 — 0 B — 43 ms — blob:https://codecademy.com/917fa632-ce97-4ebe-aa5a-ac3c2c7792cacodecademy.com/917fa632-ce97-4ebe-a... blob:https://codecademy.com/917fa632-ce97-4ebe-aa5a-ac3c2c7792ca — 200 — -1 B — 21 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/turnstile/f/ov2/av0/rch/1n474/0x4AAAAAAADnPIDROrmt1Wwj/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/1n474/0x4AAAAAAADnPIDROrmt1Wwj/light/fbE/new/normal?lang=auto — 200 — 94.5 KiB — 102 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 — 22 ms — h3blob:https://challenges.cloudflare.com/8ea283ac-c2e2-45c6-9902-a54c15f8c68achallenges.cloudflare.com/8ea283ac-... blob:https://challenges.cloudflare.com/8ea283ac-c2e2-45c6-9902-a54c15f8c68a — -1 — 0 B — 0 ms — https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/flow/ov1/1250041109:1776294715:G-MwTZZkbZJhxmTQ3ZhFFu11zimeqnMrRRnrtJ1Os6E/9eceb6917e8202e1/plWWFpNOokunFDQfXN1wEh1D8PE6tYRbE3CMHLNNwwM-1776295565-1.2.1.1-tV7eJn0NWifrcTg62L81o5AwLnnz.4P3uAqG0ZlYMy7pfjDvr1VW9lbMH4ASBwwRchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/flow/ov1/1250041109:1776294715:G-MwTZZkbZJhxmTQ3ZhFFu11zimeqnMrRRnrtJ1Os6E/9eceb6917e8202e1/plWWFpNOokunFDQfXN1wEh1D8PE6tYRbE3CMHLNNwwM-1776295565-1.2.1.1-tV7eJn0NWifrcTg62L81o5AwLnnz.4P3uAqG0ZlYMy7pfjDvr1VW9lbMH4ASBwwR — 200 — 252.1 KiB — 147 ms — h3blob:https://challenges.cloudflare.com/17219a07-d10f-437e-84cd-ee5d43cbfa11challenges.cloudflare.com/17219a07-... blob:https://challenges.cloudflare.com/17219a07-d10f-437e-84cd-ee5d43cbfa11 — 200 — -1 B — 61 ms — blobblob:https://challenges.cloudflare.com/17219a07-d10f-437e-84cd-ee5d43cbfa11challenges.cloudflare.com/17219a07-... blob:https://challenges.cloudflare.com/17219a07-d10f-437e-84cd-ee5d43cbfa11 — 200 — -1 B — 15 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/pat/9eceb6917e8202e1/1776295565326/c01398a3f90f89bb2c55126e78d77d2afa4a0222eaaa00b8c64d6d8f6ae5778b/DrM83MKI722RE4Dchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/pat/9eceb6917e8202e1/1776295565326/c01398a3f90f89bb2c55126e78d77d2afa4a0222eaaa00b8c64d6d8f6ae5778b/DrM83MKI722RE4D — 401 — 1.7 KiB — 21 ms — h3https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/d/9eceb6917e8202e1/1776295565326/vrJmNbmS_j5-U5zchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/d/9eceb6917e8202e1/1776295565326/vrJmNbmS_j5-U5z — 200 — 5.1 KiB — 21 ms — h3https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/flow/ov1/1250041109:1776294715:G-MwTZZkbZJhxmTQ3ZhFFu11zimeqnMrRRnrtJ1Os6E/9eceb6917e8202e1/plWWFpNOokunFDQfXN1wEh1D8PE6tYRbE3CMHLNNwwM-1776295565-1.2.1.1-tV7eJn0NWifrcTg62L81o5AwLnnz.4P3uAqG0ZlYMy7pfjDvr1VW9lbMH4ASBwwRchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/g/flow/ov1/1250041109:1776294715:G-MwTZZkbZJhxmTQ3ZhFFu11zimeqnMrRRnrtJ1Os6E/9eceb6917e8202e1/plWWFpNOokunFDQfXN1wEh1D8PE6tYRbE3CMHLNNwwM-1776295565-1.2.1.1-tV7eJn0NWifrcTg62L81o5AwLnnz.4P3uAqG0ZlYMy7pfjDvr1VW9lbMH4ASBwwR — 200 — 22.8 KiB — 47 ms — h3blob:https://challenges.cloudflare.com/3c0e0659-7905-46c7-9b97-33a51cf1aee0challenges.cloudflare.com/3c0e0659-... blob:https://challenges.cloudflare.com/3c0e0659-7905-46c7-9b97-33a51cf1aee0 — 200 — -1 B — 14 ms — blob
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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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