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https://www.twitch.tv

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
74
GRADE
C
FIX
3
REVIEW
4
PASS
5
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.
100
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
73
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
100
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.

6.99 s

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

13.37 s

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

6.75 s

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

0.002

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

10.06 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.

19.63 s

Page Load Progression

478 ms
957 ms
1.4 s
1.9 s
2.4 s
2.9 s
3.3 s
3.8 s
Checks
14
5 PASS 4 REVIEW 3 FIX
D
Page Weight Budget
Action
2.5 MB transferred, 170 requests
FIX
2.5 MB transferred, 170 requests
Warning::
Page weighs 5.3 MB (2.5 MB transferred)
Warning::
JavaScript is 1.3 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.3 MB
Warning::
170 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 0.53 g CO2 per page load
2.5 MB / 2.4 MB budget
2.5 MB transferred
170 requests
0.53 g CO2 per page load
JavaScript 1.3 MiB 50%
Images 1002.9 KiB 39%
Fonts 176.8 KiB 7%
HTML 70.8 KiB 3%
Other 14.3 KiB 1%
Other 4.7 KiB 0%
CSS 4.6 KiB 0%
Other 2.1 KiB 0%
Other 1.3 KiB 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

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
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (2.5 MiB of 2.5 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Execution Cost
Action
18585ms total JS execution
FIX
18585ms total JS execution
Warning::
https://assets.twitch.tv/assets/2433-0b949759e40ba...: 7963ms CPU time
Warning::
https://passport.twitch.tv/149e9513-01fa-4fb0-aad4...: 3588ms CPU time
Warning::
https://gql.twitch.tv/149e9513-01fa-4fb0-aad4-566a...: 2829ms CPU time
Warning::
Unattributable: 1301ms CPU time
Warning::
https://assets.twitch.tv/assets/mweb-main-6776654e...: 831ms CPU time
Warning::
Third-party scripts: 18585ms (100% of total)

Main Thread Breakdown

Script Evaluation 77% Other 9% Style & Layout 6% Script Parsing & Compilation 3%
ScriptTotalScriptingParse/CompileParty
https://assets.twitch.tv/assets/2433-0b949759e40ba0e099da.js7963ms6693ms129ms3rd
https://passport.twitch.tv/149e9513-01fa-4fb0-aad4-566afd725d1b/2d206a39-8ed7-437e-a3be-862e0f06eea3/ips.js?ga__15_abel=0QK3djnoAoVJAPXerB7SvjSbb0OXqBGQAkZVZmsOV5pnht0WUNDQGM8mb43C8G3YvTZK9dANKf95QvRALm8mg910dG0bkM8jnM1As56KBp83sO7CkuJEYrcKK7Q6630S5VYIDZYsjnEXgneyb0oFSybyCDLWUhrliGf6SaKiuSPd&x-kpsdk-v=j-1.2.308&x-kpsdk-im=AAKa7CCdAUPn6kswoVqrHrB1FjTDRGeIgFvkf49d-SW2VUrPp8iuAA-yPnRss9T_ZiggLCpMN22ohqx3FlFyOaKXQ-Y3588ms3381ms64ms3rd
https://gql.twitch.tv/149e9513-01fa-4fb0-aad4-566afd725d1b/2d206a39-8ed7-437e-a3be-862e0f06eea3/ips.js?KP_UIDZ_1=0Prw9JfrswUk28Ebyv8OUEEiFg77lTyTGWyBiZOuajj7KShgwZmdXTkzD7r1QGdYMQT4v7vWnvQ3xah3s3VEKtQPcQaRUDYm6eMq8mXuhnJORUWl1drCSIY3MggRwnFSxGb4SqhYEkdEm4xpFcftwqfajUWF8WUcj1Ts08YZLWhr&x-kpsdk-v=j-1.2.308&x-kpsdk-im=AAIwLOwMvxoIiYyj4GFKSzay03YPHtMQll4s7uD3VHRCakGunXIB_boXm28MpBiLd-H8GWPMhDUQWyu4pEnxeAR45QM2829ms2657ms64ms3rd
Unattributable1301ms65ms2ms3rd
https://assets.twitch.tv/assets/mweb-main-6776654e053bc9704520.js831ms822ms9ms3rd
https://m.twitch.tv/?desktop-redirect=true749ms39ms37ms3rd
https://k.twitchcdn.net/149e9513-01fa-4fb0-aad4-566afd725d1b/2d206a39-8ed7-437e-a3be-862e0f06eea3/p.js663ms636ms17ms3rd
https://app.link/_r?sdk=web2.86.0&branch_key=key_live_jgBdao5vVtyZ3hdckxy8jlkkzqooQltZ&callback=branch_callback__0272ms40ms0ms3rd
https://assets.twitch.tv/assets/91615-f0fa9c8855d6ef2ba74e.js199ms120ms72ms3rd
https://assets.twitch.tv/assets/46986-c33b193f9de78e30f624.js80ms44ms2ms3rd

Showing top 10 of 12 scripts

B
Image Optimization
90 images, 0 KB saveable
REVIEW
90 images, 0 KB saveable
Warning::
https://static-cdn.jtvnw.net/twilight-static-asset... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
90 images 1003 KB
0 oversized -0 KB
89 legacy format
1 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

C
JS Bundles
Action
44 scripts, 158 KB unused
REVIEW
44 scripts, 158 KB unused
Warning::
https://assets.twitch.tv/assets/2433-0b949759e40ba...: 86 KB unused (35%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://assets.twitch.tv/assets/flags-ff62b41fa1a6...: 39 KB unused (66%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://assets.twitch.tv/assets/91615-f0fa9c8855d6...: 33 KB unused (27%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 158 KB
158 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://assets.twitch.tv/assets/2433-0b949759e40ba0e099da.js249 KB86 KB (35%)✓3rd
https://assets.twitch.tv/assets/flags-ff62b41fa1a6ed5b8694.js58 KB39 KB (66%)✓3rd
https://assets.twitch.tv/assets/91615-f0fa9c8855d6ef2ba74e.js125 KB33 KB (27%)✓3rd
https://assets.twitch.tv/assets/33283-e77b5fb974661e6f7d78.js5 KB—✓3rd
https://assets.twitch.tv/assets/mweb-main-6776654e053bc9704520.js18 KB—✓3rd
https://assets.twitch.tv/assets/71259-3bcd239c1a3eccc7843e.js8 KB—✓3rd
https://assets.twitch.tv/assets/79004-adee6b9b24e5f508c5ba.js7 KB—✓3rd
https://assets.twitch.tv/assets/79058-307ba85d09ac48f03d14.js3 KB—✓3rd
https://assets.twitch.tv/assets/80399-4bb68412b634fa76378e.js7 KB—✓3rd
https://assets.twitch.tv/assets/22367-63138a15797201b78256.js5 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

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

Green Hosting

No green hosting detected

B
HTTP Caching
private, max-age=0
REVIEW
private, max-age=0
Info::
Cache-Control header is set
Got: private, max-age=0
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

private, max-age=0

DirectiveValueMeaning
private—Only browser cache, not CDN/proxy
max-age0Cache for 0 seconds
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
5 fonts (177 KB)
PASS
5 fonts (177 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

177 KB total

Render-blocking

0

of 5

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 FCP 7.0 s LCP 13.4 shttps://assets.twitch.tv/assets/inter-latin-variable-wghtOnly-normal-a05a0d687a088c4efed3.woff2inter-latin-variable-wg... https://assets.twitch.tv/assets/inter-latin-variable-wghtOnly-normal-a05a0d687a088c4efed3.woff2 — 36.3 KiB — 0 ms — font-display: swaphttps://assets.twitch.tv/assets/Roobert-Regular-2b0345b049d46f67090f.woff2Roobert-Regular-2b0345b... https://assets.twitch.tv/assets/Roobert-Regular-2b0345b049d46f67090f.woff2 — 28.2 KiB — 0 ms — font-display: swaphttps://assets.twitch.tv/assets/Roobert-Medium-050c71a0449f34eb9cd3.woff2Roobert-Medium-050c71a0... https://assets.twitch.tv/assets/Roobert-Medium-050c71a0449f34eb9cd3.woff2 — 27.2 KiB — 0 ms — font-display: swaphttps://assets.twitch.tv/assets/Roobert-SemiBold-2c9de19c87721c9bcb39.woff2Roobert-SemiBold-2c9de1... https://assets.twitch.tv/assets/Roobert-SemiBold-2c9de19c87721c9bcb39.woff2 — 28.4 KiB — 0 ms — font-display: swaphttps://assets.twitch.tv/assets/inter-latin-ext-variable-wghtOnly-normal-29df4aa934ecc9462070.woff2inter-latin-ext-variabl... https://assets.twitch.tv/assets/inter-latin-ext-variable-wghtOnly-normal-29df4aa934ecc9462070.woff2 — 56.6 KiB — 0 ms — font-display: swap
inter-latin-variable-wg... woff2 swap
Size 36 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Roobert-Regular-2b0345b... woff2 swap
Size 28 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Roobert-Medium-050c71a0... woff2 swap
Size 27 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Roobert-SemiBold-2c9de1... woff2 swap
Size 28 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
inter-latin-ext-variabl... woff2 swap
Size 57 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
11 hints, 0 missing preconnects
PASS
11 hints, 0 missing preconnects
Info::
Page uses 11 resource hint(s)

Current Resource Hints

preconnect
3
preload
2
dns-prefetch
6
prefetch
—

11 resource hints configured

Network Waterfall
170 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
100% of JavaScript execution is third-party
First-party Third-party 18585ms · 1051KB · $247/mo
assets.twitch.tv
Other
Costly
Execution 7963ms
Transfer 249 KB
Unused 35%
Monthly Cost $106/mo
passport.twitch.tv
Other
Costly
Execution 3588ms
Transfer 253 KB
Monthly Cost $48/mo
gql.twitch.tv
Other
Costly
Execution 2829ms
Transfer 244 KB
Monthly Cost $38/mo
Unattributable
Other
Costly
Execution 1301ms
Transfer 0 KB
Monthly Cost $17/mo
assets.twitch.tv
Other
Costly
Execution 831ms
Transfer 18 KB
Monthly Cost $11/mo
m.twitch.tv
Other
Costly
Execution 749ms
Transfer 68 KB
Monthly Cost $10/mo
k.twitchcdn.net
Other
Costly
Execution 663ms
Transfer 58 KB
Monthly Cost $9/mo
app.link
Other
Costly
Execution 272ms
Transfer 1 KB
Monthly Cost $4/mo
assets.twitch.tv
Other
Optional
Execution 199ms
Transfer 125 KB
Unused 27%
Monthly Cost $3/mo
assets.twitch.tv
Other
Optional
Execution 80ms
Transfer 6 KB
Monthly Cost $1/mo
assets.twitch.tv
Other
Optional
Execution 55ms
Transfer 8 KB
Monthly Cost $1/mo
assets.twitch.tv
Other
Optional
Execution 54ms
Transfer 21 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • assets.twitch.tv adds 7963ms and costs ~$106/month
  • passport.twitch.tv adds 3588ms and costs ~$48/month
  • gql.twitch.tv adds 2829ms and costs ~$38/month
  • Unattributable adds 1301ms and costs ~$17/month
  • assets.twitch.tv adds 831ms and costs ~$11/month
  • m.twitch.tv adds 749ms and costs ~$10/month
  • k.twitchcdn.net adds 663ms and costs ~$9/month
  • app.link adds 272ms and costs ~$4/month

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

assets.twitch.tv takes 7963ms 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

passport.twitch.tv takes 3588ms 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

gql.twitch.tv takes 2829ms 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 1301ms 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

assets.twitch.tv takes 831ms 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

m.twitch.tv takes 749ms 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

k.twitchcdn.net takes 663ms 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

app.link takes 272ms 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

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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