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Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
70
GRADE
C
FIX
4
REVIEW
2
PASS
8
INFO
2

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

Mobile Desktop
26
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
91
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
77
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.

12.09 s

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

19.90 s

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

2.58 s

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.

23.05 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.

27.20 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
8 PASS 2 REVIEW 4 FIX
F
Page Weight Budget
Action
4.7 MB transferred, 179 requests
FIX
4.7 MB transferred, 179 requests
Critical::
Page weighs 9.5 MB (4.7 MB transferred)
Warning::
JavaScript is 1.8 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.8 MB
Warning::
Images are 1.6 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 1.6 MB
Info::
Fonts are 1.1 MB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 1.1 MB
Warning::
179 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 0.99 g CO2 per page load
4.7 MB / 2.4 MB budget
4.7 MB transferred
179 requests
0.99 g CO2 per page load
JavaScript 1.8 MiB 38%
Images 1.6 MiB 34%
Fonts 1.1 MiB 24%
HTML 63.9 KiB 1%
Other 63.3 KiB 1%
CSS 53.9 KiB 1%
Other 20.9 KiB 0%
Other 1.6 KiB 0%
Other 544 B 0%
Other 288 B 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over 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

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

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

D
Third-Party Impact
Action
96% third-party, 0 ms blocking
FIX
96% third-party, 0 ms blocking
Warning::
Third-party code accounts for 96% of page weight (4.6 MiB of 4.7 MiB)
Info::
Third-party blocking time is low (0 ms)
96%
First-party Third-party
F
JS Execution Cost
Action
11648ms total JS execution
FIX
11648ms total JS execution
Warning::
https://frontends.udemycdn.com/frontends-homepage/...: 2423ms CPU time
Warning::
https://frontends.udemycdn.com/frontends-homepage/...: 2159ms CPU time
Warning::
Unattributable: 1588ms CPU time
Warning::
https://frontends.udemycdn.com/frontends-homepage/...: 956ms CPU time
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-7BF...: 760ms CPU time
Warning::
Third-party scripts: 10731ms (92% of total)

Main Thread Breakdown

Script Evaluation 62% Other 18% Style & Layout 7% Script Parsing & Compilation 5% Rendering 3%
ScriptTotalScriptingParse/CompileParty
https://frontends.udemycdn.com/frontends-homepage/_next/static/chunks/pages/_app-b224ea5cbb64cb36.js2423ms1230ms125ms3rd
https://frontends.udemycdn.com/frontends-homepage/_next/static/chunks/pages/lohp-b6ea9acfc109d4a6.js2159ms2047ms7ms3rd
Unattributable1588ms82ms0ms3rd
https://frontends.udemycdn.com/frontends-homepage/_next/static/7X7PJwEDfA63XeUwLNJKc/_buildManifest.js956ms864ms0ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-7BF3X760ms671ms62ms3rd
https://www.udemy.com/648ms75ms3ms1st
https://frontends.udemycdn.com/frontends-homepage/_next/static/chunks/649-6254f0927693bd7b.js569ms299ms56ms3rd
https://www.upsellit.com/active/Udemy.jsp433ms410ms8ms3rd
https://frontends.udemycdn.com/frontends-homepage/_next/static/chunks/framework-8b7974553b1447ee.js388ms316ms12ms3rd
https://www.googletagmanager.com/gtag/js?id=G-7YMFEFLR6Q&cx=c&gtm=4e6460293ms229ms62ms3rd

Showing top 10 of 22 scripts

F
JS Bundles
Action
36 scripts, 729 KB unused
FIX
36 scripts, 729 KB unused
Warning::
https://frontends.udemycdn.com/frontends-homepage/...: 202 KB unused (63%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://gtm.udemy.com/gtag/js?id=G-7YMFEFLR6Q: 129 KB unused (65%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-7YMF...: 76 KB unused (44%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://frontends.udemycdn.com/frontends-homepage/...: 63 KB unused (41%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=AW-877...: 61 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 729 KB
729 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://frontends.udemycdn.com/frontends-homepage/_next/static/chunks/pages/_app-b224ea5cbb64cb36.js322 KB202 KB (63%)✓3rd
https://gtm.udemy.com/gtag/js?id=G-7YMFEFLR6Q199 KB129 KB (65%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-7YMFEFLR6Q&cx=c&gtm=4e6460173 KB76 KB (44%)✓3rd
https://frontends.udemycdn.com/frontends-homepage/_next/static/chunks/649-6254f0927693bd7b.js154 KB63 KB (41%)✓3rd
https://www.googletagmanager.com/gtag/js?id=AW-877556973&cx=c&gtm=4e6460145 KB61 KB (42%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-7BF3X186 KB59 KB (32%)✓3rd
https://connect.facebook.net/en_US/fbevents.js95 KB47 KB (49%)✓3rd
https://frontends.udemycdn.com/frontends-homepage/_next/static/chunks/163-715a7e94cdaaa4ee.js93 KB39 KB (42%)✓3rd
https://cl.qualaroo.com/ki.js/34436/6GL.js80 KB32 KB (40%)✓3rd
https://frontends.udemycdn.com/frontends-homepage/_next/static/chunks/1edf0483.9dfe51f2fe978bc8.js51 KB22 KB (43%)✓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
41 images, 0 KB saveable
REVIEW
41 images, 0 KB saveable
Warning::
https://frontends.udemycdn.com/frontends-homepage/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://s.udemycdn.com/career-academies/product-ca... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://cms-images.udemycdn.com/96883mtakkm8/2tQm6... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://s.udemycdn.com/career-academies/product-ca... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://cms-images.udemycdn.com/96883mtakkm8/3Yzfv... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://cms-images.udemycdn.com/96883mtakkm8/1UUVZ... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://cms-images.udemycdn.com/96883mtakkm8/23Xnh... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://s.udemycdn.com/career-academies/product-ca... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://frontends.udemycdn.com/frontends-homepage/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://cms-images.udemycdn.com/96883mtakkm8/2pNyD... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://cms-images.udemycdn.com/96883mtakkm8/7guDR... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://frontends.udemycdn.com/frontends-homepage/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://cms-images.udemycdn.com/96883mtakkm8/3E0eI... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://cms-images.udemycdn.com/96883mtakkm8/1GoAi... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://frontends.udemycdn.com/staticx/udemy/image... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
41 images 1.6 MB
0 oversized -0 KB
18 legacy format
16 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

Performance issues directly impact user engagement and conversion rates.

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

B
HTTP Caching
s-maxage=14400, stale-while-revalidate
REVIEW
s-maxage=14400, stale-while-revalidate
Info::
Cache-Control header is set
Got: s-maxage=14400, stale-while-revalidate
Info::
CDN TTL: 4 hours (s-maxage=14400)
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

s-maxage=14400, stale-while-revalidate

DirectiveValueMeaning
s-maxage14400CDN caches for 4 hours
stale-while-revalidate—Serve stale while revalidating
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
6 fonts (1150 KB)
PASS
6 fonts (1150 KB)
Info::
6 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

6

1150 KB total

Render-blocking

0

of 6

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 2.0 s 4.0 s 6.0 s 8.0 s 10.0 s 12.0 s 14.0 s 16.0 s 18.0 s 20.0 s FCP 12.1 s LCP 19.9 shttps://frontends.udemycdn.com/thesis/fonts/Udemy-Sans-Light-v1.woff2Udemy-Sans-Light-v1.woff2 https://frontends.udemycdn.com/thesis/fonts/Udemy-Sans-Light-v1.woff2 — 34.7 KiB — 0 ms — font-display: swaphttps://frontends.udemycdn.com/thesis/fonts/Udemy-Sans-Regular-v1.woff2Udemy-Sans-Regular-v1.w... https://frontends.udemycdn.com/thesis/fonts/Udemy-Sans-Regular-v1.woff2 — 35.5 KiB — 0 ms — font-display: swaphttps://frontends.udemycdn.com/thesis/fonts/Udemy-Sans-Medium-v1.woff2Udemy-Sans-Medium-v1.woff2 https://frontends.udemycdn.com/thesis/fonts/Udemy-Sans-Medium-v1.woff2 — 35.6 KiB — 0 ms — font-display: swaphttps://frontends.udemycdn.com/thesis/fonts/Udemy-Sans-Bold-v1.woff2Udemy-Sans-Bold-v1.woff2 https://frontends.udemycdn.com/thesis/fonts/Udemy-Sans-Bold-v1.woff2 — 35.7 KiB — 0 ms — font-display: swaphttps://frontends.udemycdn.com/thesis/fonts/Vazirmatn-Light.woff2Vazirmatn-Light.woff2 https://frontends.udemycdn.com/thesis/fonts/Vazirmatn-Light.woff2 — 50.4 KiB — 0 ms — font-display: swaphttps://frontends.udemycdn.com/thesis/fonts/noto-sans-jp-japanese-400-normal.woff2noto-sans-jp-japanese-4... https://frontends.udemycdn.com/thesis/fonts/noto-sans-jp-japanese-400-normal.woff2 — 957.5 KiB — 0 ms — font-display: swap
Udemy-Sans-Light-v1.woff2 woff2 swap
Size 35 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Udemy-Sans-Regular-v1.w... woff2 swap
Size 35 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Udemy-Sans-Medium-v1.woff2 woff2 swap
Size 36 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Udemy-Sans-Bold-v1.woff2 woff2 swap
Size 36 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Vazirmatn-Light.woff2 woff2 swap
Size 50 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
noto-sans-jp-japanese-4... woff2 swap
Size 958 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 ~479 KB and ~958 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
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
179 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
92% of JavaScript execution is third-party
First-party Third-party 10731ms · 1693KB · $142/mo
frontends.udemycdn.com
Other
Costly
Execution 2423ms
Transfer 322 KB
Unused 63%
Monthly Cost $32/mo
frontends.udemycdn.com
Other
Costly
Execution 2159ms
Transfer 26 KB
Monthly Cost $29/mo
Unattributable
Other
Costly
Execution 1588ms
Transfer 0 KB
Monthly Cost $21/mo
frontends.udemycdn.com
Other
Costly
Execution 956ms
Transfer 1 KB
Monthly Cost $13/mo
Google Tag Manager
Tag Manager
Costly
Execution 760ms
Transfer 186 KB
Unused 32%
Monthly Cost $10/mo
frontends.udemycdn.com
Other
Costly
Execution 569ms
Transfer 154 KB
Unused 41%
Monthly Cost $8/mo
www.upsellit.com
Other
Costly
Execution 433ms
Transfer 18 KB
Monthly Cost $6/mo
frontends.udemycdn.com
Other
Costly
Execution 388ms
Transfer 42 KB
Monthly Cost $5/mo
Google Tag Manager
Tag Manager
Costly
Execution 293ms
Transfer 173 KB
Unused 44%
Monthly Cost $4/mo
Google Tag Manager
Tag Manager
Costly
Execution 268ms
Transfer 145 KB
Unused 42%
Monthly Cost $4/mo
frontends.udemycdn.com
Other
Optional
Execution 147ms
Transfer 93 KB
Unused 42%
Monthly Cost $2/mo
Facebook Pixel
Advertising
Optional
Execution 124ms
Transfer 95 KB
Unused 49%
Monthly Cost $2/mo
trk.udemy.com
Other
Optional
Execution 117ms
Transfer 22 KB
Monthly Cost $2/mo
frontends.udemycdn.com
Other
Optional
Execution 93ms
Transfer 51 KB
Unused 43%
Monthly Cost $1/mo
gtm.udemy.com
Other
Optional
Execution 89ms
Transfer 199 KB
Unused 65%
Monthly Cost $1/mo
cl.qualaroo.com
Other
Optional
Execution 82ms
Transfer 80 KB
Unused 40%
Monthly Cost $1/mo
Twitter/X Pixel
Advertising
Optional
Execution 67ms
Transfer 13 KB
Monthly Cost $1/mo
Google Analytics
Analytics
Optional
Execution 66ms
Transfer 21 KB
Monthly Cost $1/mo
frontends.udemycdn.com
Other
Optional
Execution 57ms
Transfer 35 KB
Monthly Cost $1/mo
Bing UET
Advertising
Optional
Execution 50ms
Transfer 16 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • frontends.udemycdn.com adds 2423ms and costs ~$32/month
  • frontends.udemycdn.com adds 2159ms and costs ~$29/month
  • Unattributable adds 1588ms and costs ~$21/month
  • frontends.udemycdn.com adds 956ms and costs ~$13/month
  • Google Tag Manager adds 760ms and costs ~$10/month
  • frontends.udemycdn.com adds 569ms and costs ~$8/month
  • www.upsellit.com adds 433ms and costs ~$6/month
  • frontends.udemycdn.com adds 388ms and costs ~$5/month
  • Google Tag Manager adds 293ms and costs ~$4/month
  • Google Tag Manager adds 268ms and costs ~$4/month

92% 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

frontends.udemycdn.com takes 2423ms 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

63% of frontends.udemycdn.com'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

frontends.udemycdn.com takes 2159ms 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 1588ms 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

frontends.udemycdn.com takes 956ms 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

Google Tag Manager takes 760ms 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

frontends.udemycdn.com takes 569ms 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

www.upsellit.com takes 433ms 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

frontends.udemycdn.com takes 388ms 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

Google Tag Manager takes 293ms 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

Google Tag Manager takes 268ms 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

65% of gtm.udemy.com'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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