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https://www.mailchimp.com

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
76
GRADE
C
FIX
3
REVIEW
3
PASS
6
INFO
2

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

Mobile Desktop
87
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.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
85
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.

800 ms

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

1.99 s

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

92 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.

1.75 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.

3.76 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 3 REVIEW 3 FIX
D
Page Weight Budget
Action
2.5 MB transferred, 163 requests
FIX
2.5 MB transferred, 163 requests
Warning::
Page weighs 7.1 MB (2.5 MB transferred)
Warning::
JavaScript is 1.5 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.5 MB
Warning::
163 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
163 requests
0.53 g CO2 per page load
JavaScript 1.5 MiB 58%
Images 622.8 KiB 24%
Fonts 178.8 KiB 7%
CSS 95.8 KiB 4%
Other 79.6 KiB 3%
HTML 77.4 KiB 3%
Other 11.4 KiB 0%
Other 5.6 KiB 0%
Other 224 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

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 Bundles
Action
91 scripts, 503 KB unused
FIX
91 scripts, 503 KB unused
Warning::
https://mailchimp.com/metrics/?id=: 80 KB unused (36%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://mailchimp.com/metrics/gtd?id=G-N5HD1RTH6E&...: 78 KB unused (43%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://accounts.google.com/gsi/client: 77 KB unused (83%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://mailchimp.com/metrics/?id=GTM-59GS5R2&gtm=...: 72 KB unused (53%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://mailchimp.com/metrics/?id=GTM-5XRCGV8&gtm=...: 71 KB unused (53%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 503 KB
503 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://mailchimp.com/metrics/?id=221 KB80 KB (36%)✓3rd
https://mailchimp.com/metrics/gtd?id=G-N5HD1RTH6E&cx=c&gtm=4e6460182 KB78 KB (43%)✓3rd
https://accounts.google.com/gsi/client93 KB77 KB (83%)✓3rd
https://mailchimp.com/metrics/?id=GTM-59GS5R2&gtm=4e6460136 KB72 KB (53%)✓3rd
https://mailchimp.com/metrics/?id=GTM-5XRCGV8&gtm=4e6460135 KB71 KB (53%)✓3rd
https://mailchimp.com/SVNV/JPUm/9J/NG64/cyzQ/5kitcDbzVkhSQkap/Ay4KP0QVAw/ex9XBDBX/LEwB173 KB37 KB (22%)✓3rd
https://plugin.intuitcdn.net/web-shell/5.60.1/integration/3935.js40 KB33 KB (85%)✓3rd
https://mailchimp.com/release/plums/cxp/js/index.570b2f64.1.js60 KB29 KB (49%)✓3rd
https://s2.go-mpulse.net/boomerang/QAT5G-9HZLF-7EDMX-YMVCJ-QZJDA58 KB24 KB (41%)✓3rd
https://mailchimp.com/release/plums/chunks/js/4073.0cd157ccb57023d8.1.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

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
34 images, 0 KB saveable
REVIEW
34 images, 0 KB saveable
Info::
All images are well-optimized
34 images 623 KB
0 oversized -0 KB
8 legacy format
0 missing dimensions CLS risk
C
JS Execution Cost
Action
1426ms total JS execution
REVIEW
1426ms total JS execution
Warning::
https://mailchimp.com/es/: 449ms CPU time
Info::
Unattributable: 235ms CPU time
Info::
https://mailchimp.com/SVNV/JPUm/9J/NG64/cyzQ/5kitc...: 198ms CPU time
Info::
https://mailchimp.com/release/plums/cxp/js/index.5...: 180ms CPU time
Info::
https://s2.go-mpulse.net/boomerang/QAT5G-9HZLF-7ED...: 97ms CPU time
Warning::
Third-party scripts: 1426ms (100% of total)

Main Thread Breakdown

Script Evaluation 51% Other 22% Style & Layout 9% Rendering 8% Script Parsing & Compilation 7%
ScriptTotalScriptingParse/CompileParty
https://mailchimp.com/es/449ms10ms3ms3rd
Unattributable235ms24ms0ms3rd
https://mailchimp.com/SVNV/JPUm/9J/NG64/cyzQ/5kitcDbzVkhSQkap/Ay4KP0QVAw/ex9XBDBX/LEwB198ms183ms11ms3rd
https://mailchimp.com/release/plums/cxp/js/index.570b2f64.1.js180ms145ms7ms3rd
https://s2.go-mpulse.net/boomerang/QAT5G-9HZLF-7EDMX-YMVCJ-QZJDA97ms35ms7ms3rd
https://mailchimp.com/metrics/?id=71ms51ms18ms3rd
https://mailchimp.com/metrics/gtd?id=G-N5HD1RTH6E&cx=c&gtm=4e646070ms51ms16ms3rd
https://plugin.intuitcdn.net/web-shell/5.60.1/integration/adk-api.js67ms63ms0ms3rd
https://mailchimp.com/release/plums/chunks/js/2362.49d5f9e21a4f8705.1.js58ms56ms0ms3rd
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
5 fonts (179 KB)
PASS
5 fonts (179 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

179 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 500 ms 1.0 s 1.5 s 2.0 s FCP 800 ms LCP 2.0 shttps://mailchimp.com/release/plums/659baf8b2573503b.woff2659baf8b2573503b.woff2 https://mailchimp.com/release/plums/659baf8b2573503b.woff2 — 32.2 KiB — 0 ms — font-display: swaphttps://mailchimp.com/release/plums/ea9371020395bcec.woff2ea9371020395bcec.woff2 https://mailchimp.com/release/plums/ea9371020395bcec.woff2 — 34.5 KiB — 0 ms — font-display: swaphttps://mailchimp.com/release/plums/b4358c1049ee69f4.woff2b4358c1049ee69f4.woff2 https://mailchimp.com/release/plums/b4358c1049ee69f4.woff2 — 36.3 KiB — 0 ms — font-display: swaphttps://mailchimp.com/release/plums/c477e5e371f1219d.woff2c477e5e371f1219d.woff2 https://mailchimp.com/release/plums/c477e5e371f1219d.woff2 — 35.2 KiB — 0 ms — font-display: swaphttps://mailchimp.com/release/plums/f503b10a8b819ad9.woff2f503b10a8b819ad9.woff2 https://mailchimp.com/release/plums/f503b10a8b819ad9.woff2 — 40.6 KiB — 0 ms — font-display: swap
659baf8b2573503b.woff2 woff2 swap
Size 32 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
ea9371020395bcec.woff2 woff2 swap
Size 34 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
b4358c1049ee69f4.woff2 woff2 swap
Size 36 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
c477e5e371f1219d.woff2 woff2 swap
Size 35 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
f503b10a8b819ad9.woff2 woff2 swap
Size 41 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
HTTP Caching
max-age=60 (1 minute)
PASS
max-age=60 (1 minute)
Info::
Cache-Control header is set
Got: max-age=60
Info::
Effective TTL: 1 minute (max-age=60)
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

max-age=60

DirectiveValueMeaning
max-age60Cache for 1 minute
Effective TTL: 60 seconds
Network Waterfall
163 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 1426ms · 606KB · $8/mo
mailchimp.com
Other
Costly
Execution 449ms
Transfer 77 KB
Monthly Cost $3/mo
Unattributable
Other
Costly
Execution 235ms
Transfer 0 KB
Monthly Cost $1/mo
mailchimp.com
Other
Optional
Execution 198ms
Transfer 1 KB
Unused 22%
Monthly Cost $1/mo
mailchimp.com
Other
Optional
Execution 180ms
Transfer 60 KB
Unused 49%
Monthly Cost $1/mo
s2.go-mpulse.net
Other
Optional
Execution 97ms
Transfer 58 KB
Unused 41%
Monthly Cost $1/mo
mailchimp.com
Other
Optional
Execution 71ms
Transfer 221 KB
Unused 36%
Monthly Cost $0/mo
mailchimp.com
Other
Optional
Execution 70ms
Transfer 182 KB
Unused 43%
Monthly Cost $0/mo
plugin.intuitcdn.net
Other
Optional
Execution 67ms
Transfer 3 KB
Monthly Cost $0/mo
mailchimp.com
Other
Optional
Execution 58ms
Transfer 3 KB
Monthly Cost $0/mo

These scripts may cost more than they're worth

  • mailchimp.com adds 449ms and costs ~$3/month
  • Unattributable adds 235ms and costs ~$1/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

mailchimp.com takes 449ms 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 235ms 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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