Skip to content
https://www.nba.com

Performance

· 16 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
72
GRADE
C
FIX
5
REVIEW
2
PASS
7
INFO
2

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

Mobile Desktop
19
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
79
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
81
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
77
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.

4.14 s

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

21.24 s

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

2.12 s

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

0.221

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

9.28 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.

27.63 s

Page Load Progression

490 ms
980 ms
1.5 s
2.0 s
2.4 s
2.9 s
3.4 s
3.9 s
Checks
16
7 PASS 2 REVIEW 5 FIX
F
Page Weight Budget
Action
7.2 MB transferred, 306 requests
FIX
7.2 MB transferred, 306 requests
Critical::
Page weighs 18.3 MB (7.2 MB transferred)
Warning::
Images are 4.1 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 4.1 MB
Warning::
JavaScript is 2.2 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 2.2 MB
Info::
CSS is 296 KB — consider purging unused styles
Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.
Got: 296 KB
Warning::
306 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 1.5 g CO2 per page load
7.2 MB / 2.4 MB budget
7.2 MB transferred
306 requests
1.5 g CO2 per page load
Images 4.1 MiB 57%
JavaScript 2.2 MiB 31%
Other 388.0 KiB 5%
CSS 295.8 KiB 4%
Fonts 129.3 KiB 2%
HTML 62.8 KiB 1%
Other 26.0 KiB 0%
Other 25.4 KiB 0%
Other 1.6 KiB 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over budget

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

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

Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.

Why this matters

CSS bundle is large — purge unused styles (PurgeCSS, Tailwind JIT) to reduce CSS payload.

Source: web.dev

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
80% third-party, 0 ms blocking
FIX
80% third-party, 0 ms blocking
Warning::
Third-party code accounts for 80% of page weight (5.7 MiB of 7.2 MiB)
Info::
Third-party blocking time is low (0 ms)
20%
80%
First-party Third-party
F
JS Execution Cost
Action
12274ms total JS execution
FIX
12274ms total JS execution
Warning::
Unattributable: 2524ms CPU time
Warning::
https://www.nba.com/: 2235ms CPU time
Warning::
https://www.nba.com/_next/static/chunks/framework-...: 2157ms CPU time
Warning::
https://www.nba.com/_next/static/chunks/pages/_app...: 1372ms CPU time
Warning::
https://www.nba.com/1DzJPN/Ccndnb/-mWb6/9kEJa/Srbe...: 1223ms CPU time
Info::
Third-party scripts: 4076ms (33% of total)

Main Thread Breakdown

Script Evaluation 50% Other 25% Style & Layout 13% Script Parsing & Compilation 5% Rendering 4%
ScriptTotalScriptingParse/CompileParty
Unattributable2524ms623ms0ms3rd
https://www.nba.com/2235ms25ms2ms1st
https://www.nba.com/_next/static/chunks/framework-ad7abf312d5d61d4.js2157ms1509ms10ms1st
https://www.nba.com/_next/static/chunks/pages/_app-1dbe48d15786d52f.js1372ms849ms106ms1st
https://www.nba.com/1DzJPN/Ccndnb/-mWb6/9kEJa/SrbeU/VpOuXpE1w7i9/NkUVAg/O2Bs/ajAMMERv?v=b5f467b2-c69b-48ae-d512-4d019fac02121223ms1037ms35ms1st
https://www.nba.com/1DzJPN/Ccndnb/-mWb6/9kEJa/SrbeU/hiOuXpE1w7i9m59pr9/ZmILAg/TVZq/Ak0jGEEB910ms816ms59ms1st
https://cdn.cookielaw.org/scripttemplates/202511.1.0/otBannerSdk.js342ms88ms38ms3rd
https://stories.usestoryteller.com/amp/20251030.4/amp-story-player-v0.js283ms190ms11ms3rd
https://tags.nba.com/nba-web/prod/utag.js279ms199ms14ms3rd
https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604070101/pubads_impl.js238ms160ms65ms3rd

Showing top 10 of 17 scripts

F
JS Bundles
Action
73 scripts, 690 KB unused
FIX
73 scripts, 690 KB unused
Warning::
https://www.nba.com/_next/static/chunks/pages/_app...: 215 KB unused (59%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://securepubads.g.doubleclick.net/pagead/mana...: 128 KB unused (70%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://siteintercept.qualtrics.com/dxjsmodule/11....: 79 KB unused (89%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cdn.cookielaw.org/scripttemplates/202511.1...: 70 KB unused (57%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://assets.adobedtm.com/82bf3c13a525/38d894c71...: 54 KB unused (43%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 690 KB
690 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.nba.com/_next/static/chunks/pages/_app-1dbe48d15786d52f.js363 KB215 KB (59%)✓1st
https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604070101/pubads_impl.js183 KB128 KB (70%)✓3rd
https://siteintercept.qualtrics.com/dxjsmodule/11.f63ef3118b6fa709f80b.chunk.js?Q_CLIENTVERSION=2.41.0&Q_CLIENTTYPE=web&Q_BRANDID=www.nba.com89 KB79 KB (89%)✓3rd
https://cdn.cookielaw.org/scripttemplates/202511.1.0/otBannerSdk.js124 KB70 KB (57%)✓3rd
https://assets.adobedtm.com/82bf3c13a525/38d894c71c0b/launch-ff3828f362fb.min.js125 KB54 KB (43%)✓3rd
https://www.nba.com/1DzJPN/Ccndnb/-mWb6/9kEJa/SrbeU/hiOuXpE1w7i9m59pr9/ZmILAg/TVZq/Ak0jGEEB171 KB34 KB (20%)✓1st
https://www.nba.com/_next/static/chunks/56642-e64dd951c9aeac79.js39 KB32 KB (83%)✓1st
https://www.nba.com/1DzJPN/Ccndnb/-mWb6/9kEJa/SrbeU/VpOuXpE1w7i9/NkUVAg/O2Bs/ajAMMERv?v=b5f467b2-c69b-48ae-d512-4d019fac0212158 KB30 KB (19%)✓1st
https://www.nba.com/_next/static/chunks/87014-1bc12c2d0e199eea.js72 KB27 KB (38%)✓1st
https://www.nba.com/_next/static/chunks/30604-0f97564389a6e33a.js43 KB20 KB (48%)✓1st

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
HTTP Caching
Action
no-store (uncacheable)
FIX
no-store (uncacheable)
Info::
Cache-Control: no-store prevents all caching
Intentional for dynamic content, but increases server load for every page view.
Got: max-age=0, no-cache, no-store
Info::
ETag present — enables conditional (304) responses
Cache-Control

max-age=0, no-cache, no-store

DirectiveValueMeaning
max-age0Cache for 0 seconds
no-cache—Cache but always revalidate first
no-store—Never cache this response
B
Image Optimization
176 images, 0 KB saveable
REVIEW
176 images, 0 KB saveable
Info::
All images are well-optimized
176 images 4.1 MB
0 oversized -0 KB
141 legacy format
0 missing dimensions CLS risk
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+
Font Loading
4 fonts (129 KB)
PASS
4 fonts (129 KB)
Info::
4 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

4

129 KB total

Render-blocking

0

of 4

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 22.0 s FCP 4.1 s LCP 21.2 shttps://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2KFO7CnqEu92Fr1ME7kSn66a... https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2 — 36.7 KiB — 0 ms — font-display: swaphttps://cdn.nba.com/next/fonts/KnockoutW05-49Liteweight.woff2KnockoutW05-49Liteweigh... https://cdn.nba.com/next/fonts/KnockoutW05-49Liteweight.woff2 — 23.7 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3KUBHMdazTgWw.woff2KFO7CnqEu92Fr1ME7kSn66a... https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3KUBHMdazTgWw.woff2 — 23.9 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/robotocondensed/v31/ieVl2ZhZI2eCN5jzbjEETS9weq8-19K7DQk6YvM.woff2ieVl2ZhZI2eCN5jzbjEETS9... https://fonts.gstatic.com/s/robotocondensed/v31/ieVl2ZhZI2eCN5jzbjEETS9weq8-19K7DQk6YvM.woff2 — 45.0 KiB — 0 ms — font-display: swap
KFO7CnqEu92Fr1ME7kSn66a... woff2 swap
Size 37 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
KnockoutW05-49Liteweigh... woff2 swap
Size 24 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a... woff2 swap
Size 24 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ieVl2ZhZI2eCN5jzbjEETS9... woff2 swap
Size 45 KB
Load time 0 ms
Start 0 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
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
Network Waterfall
306 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
33% of JavaScript execution is third-party
First-party Third-party 4076ms · 624KB · $54/mo
Unattributable
Other
Costly
Execution 2524ms
Transfer 0 KB
Monthly Cost $34/mo
OneTrust
Consent
Essential
Execution 342ms
Transfer 124 KB
Unused 57%
Monthly Cost $5/mo
stories.usestoryteller.com
Other
Costly
Execution 283ms
Transfer 22 KB
Monthly Cost $4/mo
tags.nba.com
Other
Costly
Execution 279ms
Transfer 38 KB
Monthly Cost $4/mo
securepubads.g.doubleclick.net
Other
Costly
Execution 238ms
Transfer 183 KB
Unused 70%
Monthly Cost $3/mo
assets.adobedtm.com
Other
Optional
Execution 182ms
Transfer 125 KB
Unused 43%
Monthly Cost $2/mo
siteintercept.qualtrics.com
Other
Optional
Execution 103ms
Transfer 89 KB
Unused 89%
Monthly Cost $1/mo
OneTrust
Consent
Essential
Execution 62ms
Transfer 9 KB
Monthly Cost $1/mo
securepubads.g.doubleclick.net
Other
Optional
Execution 62ms
Transfer 34 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • Unattributable adds 2524ms and costs ~$34/month
  • stories.usestoryteller.com adds 283ms and costs ~$4/month
  • tags.nba.com adds 279ms and costs ~$4/month
  • securepubads.g.doubleclick.net adds 238ms and costs ~$3/month

Unattributable takes 2524ms 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

57% of OneTrust'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

stories.usestoryteller.com takes 283ms 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

tags.nba.com takes 279ms 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

securepubads.g.doubleclick.net 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

70% of securepubads.g.doubleclick.net'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

89% of siteintercept.qualtrics.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