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Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
71
GRADE
C
FIX
5
REVIEW
2
PASS
5
INFO
2

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

Mobile Desktop
49
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.
77
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
92
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.

773 ms

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

1.09 s

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

743 ms

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

0.279

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

3.10 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.

7.82 s

Page Load Progression

611 ms
1.2 s
1.8 s
2.4 s
3.1 s
3.7 s
4.3 s
4.9 s
Checks
14
5 PASS 2 REVIEW 5 FIX
F
Page Weight Budget
Action
6.5 MB transferred, 242 requests
FIX
6.5 MB transferred, 242 requests
Critical::
Page weighs 23.2 MB (6.5 MB transferred)
Warning::
JavaScript is 5.3 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 5.3 MB
Info::
CSS is 203 KB — consider purging unused styles
Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.
Got: 203 KB
Warning::
242 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 1.4 g CO2 per page load
6.5 MB / 2.4 MB budget
6.5 MB transferred
242 requests
1.4 g CO2 per page load
JavaScript 5.3 MiB 81%
Images 811.2 KiB 12%
CSS 202.7 KiB 3%
Other 71.5 KiB 1%
HTML 69.4 KiB 1%
Fonts 28.8 KiB 0%
Other 20.5 KiB 0%
Other 17.8 KiB 0%
Other 6.9 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

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
93% third-party, 0 ms blocking
FIX
93% third-party, 0 ms blocking
Warning::
Third-party code accounts for 93% of page weight (6.0 MiB of 6.5 MiB)
Info::
Third-party blocking time is low (0 ms)
93%
First-party Third-party
F
JS Execution Cost
Action
5318ms total JS execution
FIX
5318ms total JS execution
Warning::
https://22af5ed32a4a.edge.sdk.awswaf.com/22af5ed32...: 1517ms CPU time
Warning::
https://prod.cdn-redfin.com/bundles/customer-pages...: 933ms CPU time
Warning::
Unattributable: 583ms CPU time
Warning::
https://www.redfin.com/: 460ms CPU time
Warning::
https://prod.cdn-redfin.com/bundles/customer-pages...: 372ms CPU time
Warning::
Third-party scripts: 4759ms (89% of total)

Main Thread Breakdown

Script Evaluation 69% Other 15% Script Parsing & Compilation 9%
ScriptTotalScriptingParse/CompileParty
https://22af5ed32a4a.edge.sdk.awswaf.com/22af5ed32a4a/939b6cb0e48b/challenge.js1517ms1309ms85ms3rd
https://prod.cdn-redfin.com/bundles/customer-pages-personalization/4f01b5f3087c9b5d3770.js933ms766ms27ms3rd
Unattributable583ms63ms0ms3rd
https://www.redfin.com/460ms41ms12ms1st
https://prod.cdn-redfin.com/bundles/customer-pages-personalization/c1bae9b3c77451aaa3bf.js372ms345ms10ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-TZTT5H290ms241ms37ms3rd
https://www.googletagmanager.com/gtag/js?id=DC-16107967&cx=c&gtm=4e6460277ms265ms9ms3rd
https://cdn.cookielaw.org/scripttemplates/202512.1.0/otBannerSdk.js187ms126ms37ms3rd
https://cdn.cookielaw.org/scripttemplates/202512.1.0/otGPP.js134ms121ms10ms3rd
https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwMQ.js101ms87ms12ms3rd

Showing top 10 of 17 scripts

F
JS Bundles
Action
61 scripts, 1.3 MB unused
FIX
61 scripts, 1.3 MB unused
Warning::
https://22af5ed32a4a.edge.sdk.awswaf.com/22af5ed32...: 256 KB unused (51%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://prod.cdn-redfin.com/bundles/customer-pages...: 197 KB unused (63%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://prod.cdn-redfin.com/bundles/customer-pages...: 159 KB unused (45%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://prod.cdn-redfin.com/bundles/customer-pages...: 96 KB unused (39%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://prod.cdn-redfin.com/bundles/customer-pages...: 87 KB unused (54%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 1.3 MB
1376 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://22af5ed32a4a.edge.sdk.awswaf.com/22af5ed32a4a/939b6cb0e48b/challenge.js501 KB256 KB (51%)✓3rd
https://prod.cdn-redfin.com/bundles/customer-pages-personalization/22651796b6dce9a62e9b.js314 KB197 KB (63%)✓3rd
https://prod.cdn-redfin.com/bundles/customer-pages-personalization/18b8f4f0f807e50242cd.js357 KB159 KB (45%)✓3rd
https://prod.cdn-redfin.com/bundles/customer-pages-personalization/4f01b5f3087c9b5d3770.js244 KB96 KB (39%)✓3rd
https://prod.cdn-redfin.com/bundles/customer-pages-personalization/50191368361583f43278.js162 KB87 KB (54%)✓3rd
https://accounts.google.com/gsi/client93 KB69 KB (75%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-928P0PZ00X&cx=c&gtm=4e6460160 KB66 KB (41%)✓3rd
https://cdn.cookielaw.org/scripttemplates/202512.1.0/otBannerSdk.js126 KB63 KB (50%)✓3rd
https://www.googletagmanager.com/gtag/js?id=GT-KVJ5LSL6&cx=c&gtm=4e6460129 KB56 KB (43%)✓3rd
https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwMQ.js110 KB56 KB (51%)✓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

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, private
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control

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

DirectiveValueMeaning
max-age0Cache for 0 seconds
no-cache—Cache but always revalidate first
no-store—Never cache this response
private—Only browser cache, not CDN/proxy
B
Image Optimization
41 images, 0 KB saveable
REVIEW
41 images, 0 KB saveable
Warning::
https://ssl.cdn-redfin.com/cop-assets/prod/hpwidge... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
41 images 811 KB
0 oversized -0 KB
40 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
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
2 fonts (29 KB)
PASS
2 fonts (29 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

29 KB total

Render-blocking

0

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 773 ms LCP 1.1 sdata:font/woff2;base64,d09GMgABAAAAADiwABAAAAAA2rQAADhMAAEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP0ZGVE0cGh4b…woff2;base64,d09GMgABAA... data:font/woff2;base64,d09GMgABAAAAADiwABAAAAAA2rQAADhMAAEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP0ZGVE0cGh4b… — 14.2 KiB — 0 ms — font-display: swapdata:font/woff2;base64,d09GMgABAAAAADqUABAAAAAA3LAAADoyAAEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP0ZGVE0cGh4b…woff2;base64,d09GMgABAA... data:font/woff2;base64,d09GMgABAAAAADqUABAAAAAA3LAAADoyAAEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP0ZGVE0cGh4b… — 14.6 KiB — 0 ms — font-display: swap
woff2;base64,d09GMgABAA... woff2 swap
Size 14 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
woff2;base64,d09GMgABAA... woff2 swap
Size 15 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
Network Waterfall
242 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
89% of JavaScript execution is third-party
First-party Third-party 4759ms · 2010KB · $63/mo
22af5ed32a4a.edge.sdk.awswaf.com
Other
Costly
Execution 1517ms
Transfer 501 KB
Unused 51%
Monthly Cost $20/mo
prod.cdn-redfin.com
Other
Costly
Execution 933ms
Transfer 244 KB
Unused 39%
Monthly Cost $12/mo
Unattributable
Other
Costly
Execution 583ms
Transfer 0 KB
Monthly Cost $8/mo
prod.cdn-redfin.com
Other
Costly
Execution 372ms
Transfer 70 KB
Unused 46%
Monthly Cost $5/mo
Google Tag Manager
Tag Manager
Costly
Execution 290ms
Transfer 199 KB
Unused 24%
Monthly Cost $4/mo
Google Tag Manager
Tag Manager
Costly
Execution 277ms
Transfer 129 KB
Unused 43%
Monthly Cost $4/mo
OneTrust
Consent
Essential
Execution 187ms
Transfer 126 KB
Unused 50%
Monthly Cost $2/mo
OneTrust
Consent
Essential
Execution 134ms
Transfer 22 KB
Monthly Cost $2/mo
analytics.tiktok.com
Other
Optional
Execution 101ms
Transfer 110 KB
Unused 51%
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 76ms
Transfer 144 KB
Unused 36%
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 67ms
Transfer 160 KB
Unused 41%
Monthly Cost $1/mo
Facebook Pixel
Advertising
Optional
Execution 58ms
Transfer 39 KB
Monthly Cost $1/mo
OneTrust
Consent
Essential
Execution 56ms
Transfer 9 KB
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 55ms
Transfer 129 KB
Unused 43%
Monthly Cost $1/mo
Google Tag Manager
Tag Manager
Optional
Execution 53ms
Transfer 129 KB
Unused 43%
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • 22af5ed32a4a.edge.sdk.awswaf.com adds 1517ms and costs ~$20/month
  • prod.cdn-redfin.com adds 933ms and costs ~$12/month
  • Unattributable adds 583ms and costs ~$8/month
  • prod.cdn-redfin.com adds 372ms and costs ~$5/month
  • Google Tag Manager adds 290ms and costs ~$4/month
  • Google Tag Manager adds 277ms and costs ~$4/month

89% 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

22af5ed32a4a.edge.sdk.awswaf.com takes 1517ms 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 22af5ed32a4a.edge.sdk.awswaf.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

prod.cdn-redfin.com takes 933ms 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 583ms 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

prod.cdn-redfin.com takes 372ms 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 290ms 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 277ms 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

50% 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

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

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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