Skip to content
https://w3schools.com

Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
78
GRADE
C
FIX
4
REVIEW
3
PASS
6
INFO
2

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

Mobile Desktop
95
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.
83
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.

973 ms

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

1.32 s

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

9 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.

1.13 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.

2.68 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
15
6 PASS 3 REVIEW 4 FIX
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 (1.4 MiB of 1.4 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Bundles
Action
17 scripts, 461 KB unused
FIX
17 scripts, 461 KB unused
Warning::
https://www.gstatic.com/recaptcha/releases/gTpTIWh...: 242 KB unused (67%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-9YNM...: 70 KB unused (40%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.w3schools.com/lib/topnav/main.v1.0.95....: 68 KB unused (74%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.w3schools.com/lib/topnav/main.v1.0.95....: unminified — 25 KB could be saved
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-KTC...: 59 KB unused (47%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://static.fastcmp.com/fast-cmp-stub.modern.b8...: 22 KB unused (35%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 461 KB
461 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js362 KB242 KB (67%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-9YNMTB56NB&cx=c&gtm=4e64f0175 KB70 KB (40%)✓3rd
https://www.w3schools.com/lib/topnav/main.v1.0.95.js92 KB68 KB (74%)✗3rd
https://www.googletagmanager.com/gtm.js?id=GTM-KTCFC3S127 KB59 KB (47%)✓3rd
https://static.fastcmp.com/fast-cmp-stub.modern.b8d64b2fce5dae2bd026.js61 KB22 KB (35%)✓3rd
https://www.google.com/recaptcha/api.js?render=explicit1 KB—✓3rd
https://www.w3schools.com/lib/w3codecolor.js7 KB—✓3rd
https://www.w3schools.com/lib/w3schools_footer.js?update=2025092415 KB—✗3rd
https://www.w3schools.com/lib/w3schools_features.js?update=202604166 KB—✓3rd
https://www.w3schools.com/lib/user-session/main.v1.0.51.js11 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

D
Page Weight Inventory
Action
46 resources · 1.4 MB · 461 KB savings available
FIX
46 resources · 1.4 MB · 461 KB savings available
Warning::
Page weight 383 KB over 1MB target
Got: 1.4 MB Expected: ≤ 1 MB
Info::
~461 KB of savings available
Warning::
45 third-party resources (100% of weight)
Info::
1 resources over 200KB
46 resources · 1.4 MiB · 45 third-party 382.9 KiB over 1MB target
JavaScript 68% · 961.7 KiB
Font 14% · 191.4 KiB
Image 11% · 155.3 KiB
Document 4% · 52.4 KiB
CSS 3% · 41.6 KiB
Other 0% · 4.5 KiB

~461.0 KiB of savings available

Remove unused JavaScript: 461.0 KiB
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.

B
Page Weight Budget
1.4 MB transferred, 46 requests
REVIEW
1.4 MB transferred, 46 requests
Info::
Page weighs 4.0 MB (1.4 MB transferred)
Warning::
JavaScript is 962 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 962 KB
Info::
46 HTTP requests
Info::
Estimated 0.29 g CO2 per page load
1.4 MB / 2.4 MB budget
1.4 MB transferred
46 requests
0.29 g CO2 per page load
JavaScript 961.7 KiB 68%
Fonts 191.4 KiB 14%
Images 153.0 KiB 11%
HTML 52.3 KiB 4%
CSS 41.6 KiB 3%
Other 3.4 KiB 0%
Other 2.4 KiB 0%
Other 565 B 0%
Other 551 B 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Under 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

C
Image Optimization
Action
7 images, 0 KB saveable
REVIEW
7 images, 0 KB saveable
Warning::
is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.w3schools.com/spaces/files/check3.db67... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
7 images 153 KB
0 oversized -0 KB
5 legacy format
2 missing dimensions CLS risk

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

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

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+
JS Execution Cost
439ms total JS execution
PASS
439ms total JS execution
Info::
https://www.w3schools.com/: 128ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-9YNM...: 76ms CPU time
Info::
Unattributable: 67ms CPU time
Info::
https://static.fastcmp.com/fast-cmp-stub.modern.b8...: 61ms CPU time
Info::
https://www.googletagmanager.com/gtm.js?id=GTM-KTC...: 54ms CPU time
Warning::
Third-party scripts: 439ms (100% of total)

Main Thread Breakdown

Script Evaluation 44% Other 19% Style & Layout 15% Script Parsing & Compilation 14% Parse HTML & CSS 5%
ScriptTotalScriptingParse/CompileParty
https://www.w3schools.com/128ms24ms2ms3rd
https://www.googletagmanager.com/gtag/js?id=G-9YNMTB56NB&cx=c&gtm=4e64f076ms63ms12ms3rd
Unattributable67ms2ms0ms3rd
https://static.fastcmp.com/fast-cmp-stub.modern.b8d64b2fce5dae2bd026.js61ms42ms5ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-KTCFC3S54ms45ms9ms3rd
https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js53ms28ms24ms3rd
A+
Font Loading
7 fonts (191 KB)
PASS
7 fonts (191 KB)
Info::
7 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

7

191 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 500 ms 1.0 s FCP 973 ms LCP 1.3 shttps://www.w3schools.com/lib/fonts/fontawesome.woff2?14663396fontawesome.woff2 https://www.w3schools.com/lib/fonts/fontawesome.woff2?14663396 — 18.6 KiB — 42 ms — font-display: swaphttps://www.w3schools.com/lib/fonts/source-code-pro-v14-latin-regular.woff2source-code-pro-v14-lat... https://www.w3schools.com/lib/fonts/source-code-pro-v14-latin-regular.woff2 — 13.8 KiB — 41 ms — font-display: swaphttps://www.w3schools.com/lib/fonts/roboto-mono-v13-latin-500.woff2roboto-mono-v13-latin-5... https://www.w3schools.com/lib/fonts/roboto-mono-v13-latin-500.woff2 — 12.5 KiB — 43 ms — font-display: swaphttps://www.w3schools.com/lib/fonts/source-sans-pro-v14-latin-700.woff2source-sans-pro-v14-lat... https://www.w3schools.com/lib/fonts/source-sans-pro-v14-latin-700.woff2 — 15.7 KiB — 44 ms — font-display: swaphttps://www.w3schools.com/lib/fonts/source-sans-pro-v14-latin-600.woff2source-sans-pro-v14-lat... https://www.w3schools.com/lib/fonts/source-sans-pro-v14-latin-600.woff2 — 15.9 KiB — 45 ms — font-display: swaphttps://www.w3schools.com/lib/fonts/SourceSansPro-Regular.woff2SourceSansPro-Regular.w... https://www.w3schools.com/lib/fonts/SourceSansPro-Regular.woff2 — 75.8 KiB — 56 ms — font-display: swaphttps://www.w3schools.com/lib/fonts/freckle-face-v9-latin-regular.woff2freckle-face-v9-latin-r... https://www.w3schools.com/lib/fonts/freckle-face-v9-latin-regular.woff2 — 39.1 KiB — 48 ms — font-display: swap
fontawesome.woff2 woff2 swap
Size 19 KB
Load time 42 ms
Start 161 ms
Risk FOUT — text flashes from fallback to web font
source-code-pro-v14-lat... woff2 swap
Size 14 KB
Load time 41 ms
Start 162 ms
Risk FOUT — text flashes from fallback to web font
roboto-mono-v13-latin-5... woff2 swap
Size 13 KB
Load time 43 ms
Start 162 ms
Risk FOUT — text flashes from fallback to web font
source-sans-pro-v14-lat... woff2 swap
Size 16 KB
Load time 44 ms
Start 162 ms
Risk FOUT — text flashes from fallback to web font
source-sans-pro-v14-lat... woff2 swap
Size 16 KB
Load time 45 ms
Start 162 ms
Risk FOUT — text flashes from fallback to web font
SourceSansPro-Regular.w... woff2 swap
Size 76 KB
Load time 56 ms
Start 163 ms
Risk FOUT — text flashes from fallback to web font
freckle-face-v9-latin-r... woff2 swap
Size 39 KB
Load time 48 ms
Start 163 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)
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
46 requests over 1382ms
INFO
0 ms 500 ms 1.0 s FCP 973 ms LCP 1.3 shttps://w3schools.com// https://w3schools.com/ — 301 — 86 B — 127 ms — h2https://www.w3schools.com/www.w3schools.com/ https://www.w3schools.com/ — 200 — 50.7 KiB — 18 ms — h2https://www.w3schools.com/lib/fonts/fontawesome.woff2?14663396www.w3schools.com/lib/fonts/fontawe... https://www.w3schools.com/lib/fonts/fontawesome.woff2?14663396 — 200 — 18.6 KiB — 42 ms — h2https://www.w3schools.com/lib/fonts/source-code-pro-v14-latin-regular.woff2www.w3schools.com/lib/fonts/source-... https://www.w3schools.com/lib/fonts/source-code-pro-v14-latin-regular.woff2 — 200 — 13.8 KiB — 41 ms — h2https://www.w3schools.com/lib/fonts/roboto-mono-v13-latin-500.woff2www.w3schools.com/lib/fonts/roboto-... https://www.w3schools.com/lib/fonts/roboto-mono-v13-latin-500.woff2 — 200 — 12.5 KiB — 43 ms — h2https://www.w3schools.com/lib/fonts/source-sans-pro-v14-latin-700.woff2www.w3schools.com/lib/fonts/source-... https://www.w3schools.com/lib/fonts/source-sans-pro-v14-latin-700.woff2 — 200 — 15.7 KiB — 44 ms — h2https://www.w3schools.com/lib/fonts/source-sans-pro-v14-latin-600.woff2www.w3schools.com/lib/fonts/source-... https://www.w3schools.com/lib/fonts/source-sans-pro-v14-latin-600.woff2 — 200 — 15.9 KiB — 45 ms — h2https://www.w3schools.com/lib/fonts/SourceSansPro-Regular.woff2www.w3schools.com/lib/fonts/SourceS... https://www.w3schools.com/lib/fonts/SourceSansPro-Regular.woff2 — 200 — 75.8 KiB — 56 ms — h2https://www.w3schools.com/lib/fonts/freckle-face-v9-latin-regular.woff2www.w3schools.com/lib/fonts/freckle... https://www.w3schools.com/lib/fonts/freckle-face-v9-latin-regular.woff2 — 200 — 39.1 KiB — 48 ms — h2https://www.w3schools.com/lib/topnav/main.v1.0.95.csswww.w3schools.com/lib/topnav/main.v... https://www.w3schools.com/lib/topnav/main.v1.0.95.css — 200 — 15.9 KiB — 14 ms — h2https://www.w3schools.com/lib/my-learning/main.v1.0.81.csswww.w3schools.com/lib/my-learning/m... https://www.w3schools.com/lib/my-learning/main.v1.0.81.css — 200 — 3.0 KiB — 30 ms — h2https://www.w3schools.com/lib/pathfinder/main.v1.0.12.csswww.w3schools.com/lib/pathfinder/ma... https://www.w3schools.com/lib/pathfinder/main.v1.0.12.css — 200 — 4.5 KiB — 32 ms — h2https://www.w3schools.com/lib/w3schools.css?v=1.0.1www.w3schools.com/lib/w3schools.css... https://www.w3schools.com/lib/w3schools.css?v=1.0.1 — 200 — 15.0 KiB — 37 ms — h2https://www.w3schools.com/plus/plans/main.v1.0.3.csswww.w3schools.com/plus/plans/main.v... https://www.w3schools.com/plus/plans/main.v1.0.3.css — 200 — 2.6 KiB — 34 ms — h2https://www.w3schools.com/lib/sparteo.css?v=1.0.5www.w3schools.com/lib/sparteo.css?v... https://www.w3schools.com/lib/sparteo.css?v=1.0.5 — 200 — 704 B — 35 ms — h2https://www.w3schools.com/lib/uic.js?v=1.1.0www.w3schools.com/lib/uic.js?v=1.1.... https://www.w3schools.com/lib/uic.js?v=1.1.0 — 200 — 3.0 KiB — 47 ms — h2https://www.w3schools.com/lib/uic_prov.js?v=1.4.8www.w3schools.com/lib/uic_prov.js?v... https://www.w3schools.com/lib/uic_prov.js?v=1.4.8 — 200 — 3.7 KiB — 48 ms — h2https://www.w3schools.com/lib/common-deps/main.v1.0.18.jswww.w3schools.com/lib/common-deps/m... https://www.w3schools.com/lib/common-deps/main.v1.0.18.js — 200 — 9.3 KiB — 49 ms — h2https://www.w3schools.com/lib/user-session/main.v1.0.51.jswww.w3schools.com/lib/user-session/... https://www.w3schools.com/lib/user-session/main.v1.0.51.js — 200 — 10.8 KiB — 52 ms — h2https://www.w3schools.com/lib/topnav/main.v1.0.95.jswww.w3schools.com/lib/topnav/main.v... https://www.w3schools.com/lib/topnav/main.v1.0.95.js — 200 — 92.0 KiB — 60 ms — h2https://www.w3schools.com/lib/my-learning/main.v1.0.81.jswww.w3schools.com/lib/my-learning/m... https://www.w3schools.com/lib/my-learning/main.v1.0.81.js — 200 — 20.8 KiB — 58 ms — h2https://www.w3schools.com/signup/lynxlogo.svgwww.w3schools.com/signup/lynxlogo.s... https://www.w3schools.com/signup/lynxlogo.svg — 200 — 1.6 KiB — 56 ms — h2https://www.w3schools.com/spaces/files/check3.db67d31e.svgwww.w3schools.com/spaces/files/chec... https://www.w3schools.com/spaces/files/check3.db67d31e.svg — 200 — 770 B — 57 ms — h2https://www.w3schools.com/lib/w3codecolor.jswww.w3schools.com/lib/w3codecolor.j... https://www.w3schools.com/lib/w3codecolor.js — 200 — 7.3 KiB — 12 ms — h2https://www.w3schools.com/lib/w3schools_footer.js?update=20250924www.w3schools.com/lib/w3schools_foo... https://www.w3schools.com/lib/w3schools_footer.js?update=20250924 — 200 — 14.9 KiB — 15 ms — h2https://www.w3schools.com/lib/w3schools_features.js?update=20260416www.w3schools.com/lib/w3schools_fea... https://www.w3schools.com/lib/w3schools_features.js?update=20260416 — 200 — 5.5 KiB — 12 ms — h2https://www.google.com/recaptcha/api.js?render=explicitwww.google.com/recaptcha/api.js?ren... https://www.google.com/recaptcha/api.js?render=explicit — 200 — 1013 B — 74 ms — h3https://www.w3schools.com/site.webmanifestwww.w3schools.com/site.webmanifest https://www.w3schools.com/site.webmanifest — 200 — 565 B — 14 ms — h2https://static.fastcmp.com/fast-cmp-stub.jsstatic.fastcmp.com/fast-cmp-stub.js https://static.fastcmp.com/fast-cmp-stub.js — 200 — 1.7 KiB — 66 ms — h2https://www.googletagmanager.com/gtm.js?id=GTM-KTCFC3Swww.googletagmanager.com/gtm.js?id=... https://www.googletagmanager.com/gtm.js?id=GTM-KTCFC3S — 200 — 127.2 KiB — 254 ms — h2
0 ms 500 ms 1.0 s FCP 973 ms LCP 1.3 shttps://w3schools.com// https://w3schools.com/ — 301 — 86 B — 127 ms — h2https://www.w3schools.com/www.w3schools.com/ https://www.w3schools.com/ — 200 — 50.7 KiB — 18 ms — h2https://www.w3schools.com/lib/fonts/fontawesome.woff2?14663396www.w3schools.com/lib/fonts/fontawe... https://www.w3schools.com/lib/fonts/fontawesome.woff2?14663396 — 200 — 18.6 KiB — 42 ms — h2https://www.w3schools.com/lib/fonts/source-code-pro-v14-latin-regular.woff2www.w3schools.com/lib/fonts/source-... https://www.w3schools.com/lib/fonts/source-code-pro-v14-latin-regular.woff2 — 200 — 13.8 KiB — 41 ms — h2https://www.w3schools.com/lib/fonts/roboto-mono-v13-latin-500.woff2www.w3schools.com/lib/fonts/roboto-... https://www.w3schools.com/lib/fonts/roboto-mono-v13-latin-500.woff2 — 200 — 12.5 KiB — 43 ms — h2https://www.w3schools.com/lib/fonts/source-sans-pro-v14-latin-700.woff2www.w3schools.com/lib/fonts/source-... https://www.w3schools.com/lib/fonts/source-sans-pro-v14-latin-700.woff2 — 200 — 15.7 KiB — 44 ms — h2https://www.w3schools.com/lib/fonts/source-sans-pro-v14-latin-600.woff2www.w3schools.com/lib/fonts/source-... https://www.w3schools.com/lib/fonts/source-sans-pro-v14-latin-600.woff2 — 200 — 15.9 KiB — 45 ms — h2https://www.w3schools.com/lib/fonts/SourceSansPro-Regular.woff2www.w3schools.com/lib/fonts/SourceS... https://www.w3schools.com/lib/fonts/SourceSansPro-Regular.woff2 — 200 — 75.8 KiB — 56 ms — h2https://www.w3schools.com/lib/fonts/freckle-face-v9-latin-regular.woff2www.w3schools.com/lib/fonts/freckle... https://www.w3schools.com/lib/fonts/freckle-face-v9-latin-regular.woff2 — 200 — 39.1 KiB — 48 ms — h2https://www.w3schools.com/lib/topnav/main.v1.0.95.csswww.w3schools.com/lib/topnav/main.v... https://www.w3schools.com/lib/topnav/main.v1.0.95.css — 200 — 15.9 KiB — 14 ms — h2https://www.w3schools.com/lib/my-learning/main.v1.0.81.csswww.w3schools.com/lib/my-learning/m... https://www.w3schools.com/lib/my-learning/main.v1.0.81.css — 200 — 3.0 KiB — 30 ms — h2https://www.w3schools.com/lib/pathfinder/main.v1.0.12.csswww.w3schools.com/lib/pathfinder/ma... https://www.w3schools.com/lib/pathfinder/main.v1.0.12.css — 200 — 4.5 KiB — 32 ms — h2https://www.w3schools.com/lib/w3schools.css?v=1.0.1www.w3schools.com/lib/w3schools.css... https://www.w3schools.com/lib/w3schools.css?v=1.0.1 — 200 — 15.0 KiB — 37 ms — h2https://www.w3schools.com/plus/plans/main.v1.0.3.csswww.w3schools.com/plus/plans/main.v... https://www.w3schools.com/plus/plans/main.v1.0.3.css — 200 — 2.6 KiB — 34 ms — h2https://www.w3schools.com/lib/sparteo.css?v=1.0.5www.w3schools.com/lib/sparteo.css?v... https://www.w3schools.com/lib/sparteo.css?v=1.0.5 — 200 — 704 B — 35 ms — h2https://www.w3schools.com/lib/uic.js?v=1.1.0www.w3schools.com/lib/uic.js?v=1.1.... https://www.w3schools.com/lib/uic.js?v=1.1.0 — 200 — 3.0 KiB — 47 ms — h2https://www.w3schools.com/lib/uic_prov.js?v=1.4.8www.w3schools.com/lib/uic_prov.js?v... https://www.w3schools.com/lib/uic_prov.js?v=1.4.8 — 200 — 3.7 KiB — 48 ms — h2https://www.w3schools.com/lib/common-deps/main.v1.0.18.jswww.w3schools.com/lib/common-deps/m... https://www.w3schools.com/lib/common-deps/main.v1.0.18.js — 200 — 9.3 KiB — 49 ms — h2https://www.w3schools.com/lib/user-session/main.v1.0.51.jswww.w3schools.com/lib/user-session/... https://www.w3schools.com/lib/user-session/main.v1.0.51.js — 200 — 10.8 KiB — 52 ms — h2https://www.w3schools.com/lib/topnav/main.v1.0.95.jswww.w3schools.com/lib/topnav/main.v... https://www.w3schools.com/lib/topnav/main.v1.0.95.js — 200 — 92.0 KiB — 60 ms — h2https://www.w3schools.com/lib/my-learning/main.v1.0.81.jswww.w3schools.com/lib/my-learning/m... https://www.w3schools.com/lib/my-learning/main.v1.0.81.js — 200 — 20.8 KiB — 58 ms — h2https://www.w3schools.com/signup/lynxlogo.svgwww.w3schools.com/signup/lynxlogo.s... https://www.w3schools.com/signup/lynxlogo.svg — 200 — 1.6 KiB — 56 ms — h2https://www.w3schools.com/spaces/files/check3.db67d31e.svgwww.w3schools.com/spaces/files/chec... https://www.w3schools.com/spaces/files/check3.db67d31e.svg — 200 — 770 B — 57 ms — h2https://www.w3schools.com/lib/w3codecolor.jswww.w3schools.com/lib/w3codecolor.j... https://www.w3schools.com/lib/w3codecolor.js — 200 — 7.3 KiB — 12 ms — h2https://www.w3schools.com/lib/w3schools_footer.js?update=20250924www.w3schools.com/lib/w3schools_foo... https://www.w3schools.com/lib/w3schools_footer.js?update=20250924 — 200 — 14.9 KiB — 15 ms — h2https://www.w3schools.com/lib/w3schools_features.js?update=20260416www.w3schools.com/lib/w3schools_fea... https://www.w3schools.com/lib/w3schools_features.js?update=20260416 — 200 — 5.5 KiB — 12 ms — h2https://www.google.com/recaptcha/api.js?render=explicitwww.google.com/recaptcha/api.js?ren... https://www.google.com/recaptcha/api.js?render=explicit — 200 — 1013 B — 74 ms — h3https://www.w3schools.com/site.webmanifestwww.w3schools.com/site.webmanifest https://www.w3schools.com/site.webmanifest — 200 — 565 B — 14 ms — h2https://static.fastcmp.com/fast-cmp-stub.jsstatic.fastcmp.com/fast-cmp-stub.js https://static.fastcmp.com/fast-cmp-stub.js — 200 — 1.7 KiB — 66 ms — h2https://www.googletagmanager.com/gtm.js?id=GTM-KTCFC3Swww.googletagmanager.com/gtm.js?id=... https://www.googletagmanager.com/gtm.js?id=GTM-KTCFC3S — 200 — 127.2 KiB — 254 ms — h2https://www.w3schools.com/howto/tryhow_js_slideshow_ifr.htmwww.w3schools.com/howto/tryhow_js_s... https://www.w3schools.com/howto/tryhow_js_slideshow_ifr.htm — 200 — 1.6 KiB — 11 ms — h2https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.jswww.gstatic.com/recaptcha/releases/... https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js — 200 — 362.4 KiB — 273 ms — h2https://www.w3schools.com/howto/img_nature_wide.jpgwww.w3schools.com/howto/img_nature_... https://www.w3schools.com/howto/img_nature_wide.jpg — 200 — 51.0 KiB — 12 ms — h2https://www.w3schools.com/howto/img_snow_wide.jpgwww.w3schools.com/howto/img_snow_wi... https://www.w3schools.com/howto/img_snow_wide.jpg — 200 — 32.8 KiB — 13 ms — h2https://www.w3schools.com/howto/img_mountains_wide.jpgwww.w3schools.com/howto/img_mountai... https://www.w3schools.com/howto/img_mountains_wide.jpg — 200 — 59.3 KiB — 12 ms — h2https://sync.sparteo.com/crossfire.jssync.sparteo.com/crossfire.js https://sync.sparteo.com/crossfire.js — 200 — 12.7 KiB — 69 ms — h2https://static.fastcmp.com/fast-cmp-stub.modern.b8d64b2fce5dae2bd026.jsstatic.fastcmp.com/fast-cmp-stub.mo... https://static.fastcmp.com/fast-cmp-stub.modern.b8d64b2fce5dae2bd026.js — 200 — 61.4 KiB — 38 ms — h2https://eu.fastcmp.com/consent-require-renewal?_profile=stub-2eu.fastcmp.com/consent-require-rene... https://eu.fastcmp.com/consent-require-renewal?_profile=stub-2 — 204 — 0 B — 72 ms — h2https://eu.fastcmp.com/consent-require-renewal?_profile=stub-2eu.fastcmp.com/consent-require-rene... https://eu.fastcmp.com/consent-require-renewal?_profile=stub-2 — 200 — 3.0 KiB — 30 ms — h2https://www.googletagmanager.com/gtag/js?id=G-9YNMTB56NB&cx=c&gtm=4e64f0www.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=G-9YNMTB56NB&cx=c&gtm=4e64f0 — 200 — 174.7 KiB — 108 ms — h2https://t.fastcmp.com/beacont.fastcmp.com/beacon https://t.fastcmp.com/beacon — 200 — 212 B — 105 ms — h2https://t.fastcmp.com/beacont.fastcmp.com/beacon https://t.fastcmp.com/beacon — 200 — 213 B — 85 ms — h2https://static.fastcmp.com/fast-cmp-en-tcfeuv2.82b16153b940a36e2f80.jsstatic.fastcmp.com/fast-cmp-en-tcfe... https://static.fastcmp.com/fast-cmp-en-tcfeuv2.82b16153b940a36e2f80.js — 200 — 53.7 KiB — 27 ms — h2https://www.w3schools.com/images/w3schools_logo_500_04AA6D.webpwww.w3schools.com/images/w3schools_... https://www.w3schools.com/images/w3schools_logo_500_04AA6D.webp — 200 — 7.5 KiB — 10 ms — h2https://www.w3schools.com/favicon.icowww.w3schools.com/favicon.ico https://www.w3schools.com/favicon.ico — 200 — 2.3 KiB — 10 ms — h2https://region1.google-analytics.com/g/collect?v=2&tid=G-9YNMTB56NB&gtm=45je64f0v9104228927z8846712008za20gzb846712008zd846712008&_p=1776362305864&gcs=G100&gcd=13q3pPp2q5l1&npa=1&dma_cps=-&dma=1&tcfd=1642v&gdid=dMmMwZj&are=1&cid=1166431306.1776362307&frm=0&pscdl=denied&rcb=7&sr=800x600&uaa=x86&uab=64&uafvl=Chromium%3B147.0.7727.55%7CNot.A%252FBrand%3B8.0.0.0&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115938466~115938468~116363097~117266400~117512543&sid=1776362306&sct=1&seg=0&dl=https%3A%2F%2Fwww.w3schools.com%2F&dt=W3Schools%20Online%20Web%20Tutorials&en=page_view&_fv=1&_nsi=1&_ss=1&ep.content_group=W3Schools%20Home&tfd=1316region1.google-analytics.com/g/coll... https://region1.google-analytics.com/g/collect?v=2&tid=G-9YNMTB56NB&gtm=45je64f0v9104228927z8846712008za20gzb846712008zd846712008&_p=1776362305864&gcs=G100&gcd=13q3pPp2q5l1&npa=1&dma_cps=-&dma=1&tcfd=1642v&gdid=dMmMwZj&are=1&cid=1166431306.1776362307&frm=0&pscdl=denied&rcb=7&sr=800x600&uaa=x86&uab=64&uafvl=Chromium%3B147.0.7727.55%7CNot.A%252FBrand%3B8.0.0.0&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115938466~115938468~116363097~117266400~117512543&sid=1776362306&sct=1&seg=0&dl=https%3A%2F%2Fwww.w3schools.com%2F&dt=W3Schools%20Online%20Web%20Tutorials&en=page_view&_fv=1&_nsi=1&_ss=1&ep.content_group=W3Schools%20Home&tfd=1316 — 204 — 551 B — 65 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
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 439ms · 776KB · $3/mo
www.w3schools.com
Other
Optional
Execution 128ms
Transfer 51 KB
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 76ms
Transfer 175 KB
Unused 40%
Monthly Cost $0/mo
Unattributable
Other
Optional
Execution 67ms
Transfer 0 KB
Monthly Cost $0/mo
static.fastcmp.com
Other
Optional
Execution 61ms
Transfer 61 KB
Unused 35%
Monthly Cost $0/mo
Google Tag Manager
Tag Manager
Optional
Execution 54ms
Transfer 127 KB
Unused 47%
Monthly Cost $0/mo
www.gstatic.com
Other
Optional
Execution 53ms
Transfer 362 KB
Unused 67%
Monthly Cost $0/mo

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

67% of www.gstatic.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.

Send Feedback