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https://edmunds.com

Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
91
GRADE
A
FIX
2
REVIEW
2
PASS
11
INFO
2

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

Mobile Desktop
90
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
85
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
80
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.

2.78 s

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

2.90 s

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

27 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.

2.78 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.

2.97 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
17
11 PASS 2 REVIEW 2 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 (170.1 KiB of 170.3 KiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
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.

C
JS Execution Cost
Action
1322ms total JS execution
REVIEW
1322ms total JS execution
Warning::
https://www.edmunds.com/dCX7AW/6H/oe/qASd/a5ptcu0K...: 966ms CPU time
Warning::
Unattributable: 291ms CPU time
Info::
https://www.edmunds.com/: 65ms CPU time
Warning::
Third-party scripts: 1322ms (100% of total)

Main Thread Breakdown

Script Evaluation 79% Other 12% Style & Layout 4%
ScriptTotalScriptingParse/CompileParty
https://www.edmunds.com/dCX7AW/6H/oe/qASd/a5ptcu0Ko_/0LNimti33caV/Rjt6GwE/eTZ/eHSt4AFwPAg?v=bc442236-264b-b7e6-931c-886a2c99173b&t=576098690966ms906ms36ms3rd
Unattributable291ms131ms0ms3rd
https://www.edmunds.com/65ms4ms1ms3rd
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Page Weight Budget
170 KB transferred, 8 requests
PASS
170 KB transferred, 8 requests
Info::
Page weighs 462 KB (170 KB transferred)
Info::
8 HTTP requests
Info::
Estimated 0.03 g CO2 per page load
170 KB / 2.4 MB budget
170 KB transferred
8 requests
0.03 g CO2 per page load
JavaScript 156.6 KiB 92%
HTML 9.3 KiB 5%
Other 4.4 KiB 3%
Other 15 B 0%
0 2.4 MB 4.9 MB
Under budget
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+
Image Optimization
No images on this page
PASS
No images on this page
Info::
No images on this page
0 images 0 KB
0 oversized -0 KB
0 legacy format
0 missing dimensions CLS risk
A+
Font Loading
No web fonts (system fonts)
PASS
No web fonts (system fonts)
Info::
No web fonts loaded — system fonts are fastest
No web fonts loaded — system fonts are optimal.
A+
JS Bundles
2 scripts, 33 KB unused
PASS
2 scripts, 33 KB unused
Warning::
https://www.edmunds.com/dCX7AW/6H/oe/qASd/a5ptcu0K...: 33 KB unused (21%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 33 KB
33 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.edmunds.com/dCX7AW/6H/oe/qASd/a5ptcu0Ko_/0LNimti33caV/Rjt6GwE/eTZ/eHSt4AFwPAg?v=bc442236-264b-b7e6-931c-886a2c99173b&t=576098690157 KB33 KB (21%)✓3rd
blob:https://www.edmunds.com/78ad2a45-20a8-4790-8488-bb03166b16680 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

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
Page Weight Inventory
8 resources · 170 KB · 33 KB savings available
PASS
8 resources · 170 KB · 33 KB savings available
Info::
Within 1MB page-weight target
Got: 170 KB
Warning::
7 third-party resources (100% of weight)
8 resources · 170.3 KiB · 7 third-party Within 1MB page-weight target
JavaScript 92% · 156.6 KiB
Document 5% · 9.3 KiB
Image 2% · 4.2 KiB
Other 0% · 256 B

~33.0 KiB of savings available

Remove unused JavaScript: 33.0 KiB
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
8 requests over 3215ms
INFO
0 ms 1.0 s 2.0 s 3.0 s FCP 2.8 s LCP 2.9 shttps://edmunds.com// https://edmunds.com/ — 301 — 241 B — 59 ms — h2https://www.edmunds.com/www.edmunds.com/ https://www.edmunds.com/ — 200 — 3.1 KiB — 111 ms — h2https://www.edmunds.com/dCX7AW/6H/oe/qASd/a5ptcu0Ko_/0LNimti33caV/Rjt6GwE/eTZ/eHSt4AFwPAg?v=bc442236-264b-b7e6-931c-886a2c99173b&t=576098690www.edmunds.com/dCX7AW/6H/oe/qASd/a... https://www.edmunds.com/dCX7AW/6H/oe/qASd/a5ptcu0Ko_/0LNimti33caV/Rjt6GwE/eTZ/eHSt4AFwPAg?v=bc442236-264b-b7e6-931c-886a2c99173b&t=576098690 — 200 — 156.6 KiB — 16 ms — h2https://www.edmunds.com/favicon.icowww.edmunds.com/favicon.ico https://www.edmunds.com/favicon.ico — 200 — 4.2 KiB — 21 ms — h3blob:https://www.edmunds.com/78ad2a45-20a8-4790-8488-bb03166b1668www.edmunds.com/78ad2a45-20a8-4790-... blob:https://www.edmunds.com/78ad2a45-20a8-4790-8488-bb03166b1668 — -1 — 0 B — 0 ms — https://www.edmunds.com/dCX7AW/6H/oe/qASd/a5ptcu0Ko_/0LNimti33caV/Rjt6GwE/eTZ/eHSt4AFwPAg?t=576098690www.edmunds.com/dCX7AW/6H/oe/qASd/a... https://www.edmunds.com/dCX7AW/6H/oe/qASd/a5ptcu0Ko_/0LNimti33caV/Rjt6GwE/eTZ/eHSt4AFwPAg?t=576098690 — 200 — 15 B — 100 ms — h3https://www.edmunds.com/www.edmunds.com/ https://www.edmunds.com/ — 403 — 6.2 KiB — 28 ms — h3https://www.edmunds.com/favicon.icowww.edmunds.com/favicon.ico https://www.edmunds.com/favicon.ico — 200 — 0 B — 1 ms — h3
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 1322ms · 163KB · $18/mo
www.edmunds.com
Other
Costly
Execution 966ms
Transfer 157 KB
Unused 21%
Monthly Cost $13/mo
Unattributable
Other
Costly
Execution 291ms
Transfer 0 KB
Monthly Cost $4/mo
www.edmunds.com
Other
Optional
Execution 65ms
Transfer 6 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • www.edmunds.com adds 966ms and costs ~$13/month
  • Unattributable adds 291ms 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

www.edmunds.com takes 966ms 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 291ms 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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