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https://www.eventbrite.com

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
66
GRADE
D
FIX
4
REVIEW
2
PASS
6
INFO
2

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

Mobile Desktop
70
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
95
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.
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.

547 ms

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

1.82 s

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

465 ms

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

0.006

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

1.68 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.

6.33 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
14
6 PASS 2 REVIEW 4 FIX
F
Page Weight Budget
Action
4.5 MB transferred, 160 requests
FIX
4.5 MB transferred, 160 requests
Critical::
Page weighs 11.7 MB (4.5 MB transferred)
Warning::
JavaScript is 2.8 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 2.8 MB
Info::
CSS is 319 KB — consider purging unused styles
Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.
Got: 319 KB
Info::
Fonts are 209 KB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 209 KB
Warning::
160 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 0.94 g CO2 per page load
4.5 MB / 2.4 MB budget
4.5 MB transferred
160 requests
0.94 g CO2 per page load
JavaScript 2.8 MiB 64%
Images 862.4 KiB 19%
CSS 318.7 KiB 7%
Fonts 208.8 KiB 5%
Other 174.7 KiB 4%
Other 50.0 KiB 1%
HTML 28.7 KiB 1%
Other 4.0 KiB 0%
Other 3.6 KiB 0%
Other 1.9 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

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

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
74% third-party, 0 ms blocking
FIX
74% third-party, 0 ms blocking
Warning::
Third-party code accounts for 74% of page weight (3.3 MiB of 4.5 MiB)
Info::
Third-party blocking time is low (0 ms)
26%
74%
First-party Third-party
D
JS Execution Cost
Action
3048ms total JS execution
FIX
3048ms total JS execution
Warning::
https://www.eventbrite.com/home/_next/static/chunk...: 396ms CPU time
Warning::
https://www.eventbrite.com/: 361ms CPU time
Warning::
Unattributable: 339ms CPU time
Warning::
https://t.contentsquare.net/uxa/757e6910546e7.js: 269ms CPU time
Info::
https://www.googletagmanager.com/gtm.js?id=GTM-5P8...: 248ms CPU time
Warning::
Third-party scripts: 1962ms (64% of total)

Main Thread Breakdown

Script Evaluation 65% Other 13% Style & Layout 9% Script Parsing & Compilation 8%
ScriptTotalScriptingParse/CompileParty
https://www.eventbrite.com/home/_next/static/chunks/framework-945b357d4a851f4b.js396ms360ms6ms1st
https://www.eventbrite.com/361ms3ms0ms1st
Unattributable339ms41ms0ms3rd
https://t.contentsquare.net/uxa/757e6910546e7.js269ms240ms16ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-5P8FXJ248ms189ms28ms3rd
https://js.hs-analytics.net/analytics/1775326800000/8020908.js233ms132ms4ms3rd
https://www.eventbrite.com/home/_next/static/chunks/pages/_app-58f20aaeb5cf3bf9.js123ms88ms30ms1st
https://www.eventbrite.com/home/_next/static/chunks/613.51b8f752b880b047.js121ms82ms5ms1st
https://www.googletagmanager.com/gtag/js?id=AW-1071787441&cx=c&gtm=4e6411105ms93ms12ms3rd
https://www.googletagmanager.com/gtag/js?id=AW-10956076365&cx=c&gtm=4e6411100ms89ms10ms3rd

Showing top 10 of 19 scripts

F
JS Bundles
Action
60 scripts, 1.1 MB unused
FIX
60 scripts, 1.1 MB unused
Warning::
https://www.eventbrite.com/home/_next/static/chunk...: 130 KB unused (100%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.eventbrite.com/home/_next/static/chunk...: 109 KB unused (54%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=AW-107...: 104 KB unused (73%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://t.contentsquare.net/uxa/757e6910546e7.js: 79 KB unused (49%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-TQVE...: 66 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 1.1 MB
1076 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.eventbrite.com/home/_next/static/chunks/3b999911-e0f67891397df603.js130 KB130 KB (100%)✓1st
https://www.eventbrite.com/home/_next/static/chunks/pages/_app-58f20aaeb5cf3bf9.js204 KB109 KB (54%)✓1st
https://www.googletagmanager.com/gtag/js?id=AW-1071787441143 KB104 KB (73%)✓3rd
https://t.contentsquare.net/uxa/757e6910546e7.js161 KB79 KB (49%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-TQVES5V6SH&cx=c&gtm=4e6411159 KB66 KB (42%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-5P8FXJ194 KB65 KB (34%)✓3rd
https://www.googletagmanager.com/gtag/js?id=DC-4080218&cx=c&gtm=4e6411130 KB58 KB (45%)✓3rd
https://www.eventbrite.com/home/_next/static/chunks/5631-74ddad1e2f1aec2d.js186 KB58 KB (31%)✓1st
https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwMQ.js110 KB56 KB (51%)✓3rd
https://www.googletagmanager.com/gtag/js?id=AW-1012298015&cx=c&gtm=4e6411145 KB55 KB (38%)✓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

B
Image Optimization
40 images, 0 KB saveable
REVIEW
40 images, 0 KB saveable
Info::
All images are well-optimized
40 images 862 KB
0 oversized -0 KB
34 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 (209 KB)
PASS
4 fonts (209 KB)
Info::
4 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

4

209 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 500 ms 1.0 s 1.5 s FCP 547 ms LCP 1.8 shttps://www.eventbrite.com/home/_next/static/media/374b3182e5e57bcb-s.p.woff2374b3182e5e57bcb-s.p.woff2 https://www.eventbrite.com/home/_next/static/media/374b3182e5e57bcb-s.p.woff2 — 34.3 KiB — 0 ms — font-display: swapdata:application/font-woff;base64,d09GRgABAAAAAPvQABIAAAACEEQAAQAyAAAAAAAAAAAAAAAAAAAAAAAAAABGRlRNA…font-woff;base64,d09GRg... data:application/font-woff;base64,d09GRgABAAAAAPvQABIAAAACEEQAAQAyAAAAAAAAAAAAAAAAAAAAAAAAAABGRlRNA… — 63.0 KiB — 0 ms — font-display: swapdata:application/font-woff;base64,d09GRgABAAAAAPyMABIAAAACEGgAAQAyAAAAAAAAAAAAAAAAAAAAAAAAAABGRlRNA…font-woff;base64,d09GRg... data:application/font-woff;base64,d09GRgABAAAAAPyMABIAAAACEGgAAQAyAAAAAAAAAAAAAAAAAAAAAAAAAABGRlRNA… — 63.1 KiB — 0 ms — font-display: swapdata:application/font-woff;base64,d09GRgABAAAAAMHYABIAAAABibwAAQAyAAAAAAAAAAAAAAAAAAAAAAAAAABGRlRNA…font-woff;base64,d09GRg... data:application/font-woff;base64,d09GRgABAAAAAMHYABIAAAABibwAAQAyAAAAAAAAAAAAAAAAAAAAAAAAAABGRlRNA… — 48.5 KiB — 0 ms — font-display: swap
374b3182e5e57bcb-s.p.woff2 woff2 swap
Size 34 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
font-woff;base64,d09GRg... woff swap
Size 63 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
font-woff;base64,d09GRg... woff swap
Size 63 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
font-woff;base64,d09GRg... woff swap
Size 48 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
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 ~52 KB and ~104 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+
HTTP Caching
max-age=300 (5 minutes)
PASS
max-age=300 (5 minutes)
Info::
Cache-Control header is set
Got: max-age=300, s-maxage=600, stale-while-revalidate=3600, stale-if-error=86400
Info::
Effective TTL: 5 minutes (max-age=300)
Info::
CDN TTL: 10 minutes (s-maxage=600)
Info::
ETag present — enables conditional (304) responses
Cache-Control

max-age=300, s-maxage=600, stale-while-revalidate=3600, stale-if-error=86400

DirectiveValueMeaning
max-age300Cache for 5 minutes
s-maxage600CDN caches for 10 minutes
stale-while-revalidate3600Serve stale for 1 hour while fetching fresh
stale-if-error86400
Effective TTL: 300 seconds
Network Waterfall
160 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
64% of JavaScript execution is third-party
First-party Third-party 1962ms · 1562KB · $26/mo
Unattributable
Other
Costly
Execution 339ms
Transfer 0 KB
Monthly Cost $4/mo
t.contentsquare.net
Other
Costly
Execution 269ms
Transfer 161 KB
Unused 49%
Monthly Cost $4/mo
Google Tag Manager
Tag Manager
Costly
Execution 248ms
Transfer 194 KB
Unused 34%
Monthly Cost $3/mo
HubSpot Analytics
Analytics
Costly
Execution 233ms
Transfer 43 KB
Monthly Cost $3/mo
Google Tag Manager
Tag Manager
Optional
Execution 105ms
Transfer 143 KB
Unused 38%
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 100ms
Transfer 145 KB
Unused 38%
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 97ms
Transfer 143 KB
Unused 38%
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 96ms
Transfer 130 KB
Unused 45%
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 89ms
Transfer 145 KB
Unused 38%
Monthly Cost $1/mo
analytics.tiktok.com
Other
Optional
Execution 86ms
Transfer 110 KB
Unused 51%
Monthly Cost $1/mo
Facebook Pixel
Advertising
Optional
Execution 84ms
Transfer 95 KB
Unused 36%
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 77ms
Transfer 159 KB
Unused 42%
Monthly Cost $1/mo
cdntranscend.eventbrite.com
Other
Optional
Execution 74ms
Transfer 91 KB
Unused 50%
Monthly Cost $1/mo
js.hsadspixel.net
Other
Optional
Execution 65ms
Transfer 4 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • Unattributable adds 339ms and costs ~$4/month
  • t.contentsquare.net adds 269ms and costs ~$4/month
  • Google Tag Manager adds 248ms and costs ~$3/month
  • HubSpot Analytics adds 233ms and costs ~$3/month

64% of JavaScript execution time comes from third-party scripts.

Why this matters

Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.

Learn more ▾

Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.

Source: web.dev / HTTP Archive Web Almanac

Unattributable takes 339ms 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

t.contentsquare.net takes 269ms 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 248ms 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

HubSpot Analytics takes 233ms 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

51% of analytics.tiktok.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

50% of cdntranscend.eventbrite.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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