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https://city-data.com

Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
89
GRADE
B
FIX
2
REVIEW
1
PASS
10
INFO
2

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

93
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
64
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.
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.

1.28 s

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

1.31 s

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

5 ms

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.

1.28 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.

1.67 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
15
10 PASS 1 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 (568.2 KiB of 568.3 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.

B
JS Bundles
8 scripts, 60 KB unused
REVIEW
8 scripts, 60 KB unused
Warning::
https://www.googletagmanager.com/gtag/js?id=G-VPW5...: 60 KB unused (39%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 60 KB
60 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.googletagmanager.com/gtag/js?id=G-VPW5MZTH4E153 KB60 KB (39%)3rd
https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js34 KB3rd
https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/js/bootstrap.min.js10 KB3rd
https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js54 KB3rd
https://www.google-analytics.com/ga.js17 KB3rd
https://secure.quantserve.com/quant.js12 KB3rd
https://www.city-data.com/a/util.js24 KB3rd
https://www.city-data.com/js/cookie_notifier_js.php0 KB3rd

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+
Page Weight Budget
568 KB transferred, 25 requests
PASS
568 KB transferred, 25 requests
Info::
Page weighs 1.5 MB (568 KB transferred)
Info::
25 HTTP requests
Info::
Estimated 0.12 g CO2 per page load
568 KB / 2.4 MB budget
568 KB transferred
25 requests
0.12 g CO2 per page load
JavaScript 304.7 KiB 54%
HTML 231.7 KiB 41%
Other 16.9 KiB 3%
Fonts 13.7 KiB 2%
Other 747 B 0%
Other 550 B 0%
Images 0 B 0%
CSS 0 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
5 images, 0 KB saveable
PASS
5 images, 0 KB saveable
Warning::
https://pics3.city-data.com/assets/desktop/maps/st... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEA... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
5 images 0 KB
0 oversized -0 KB
0 legacy format
3 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

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

Set explicit width and height to prevent CLS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

A+
JS Execution Cost
389ms total JS execution
PASS
389ms total JS execution
Info::
https://www.city-data.com/: 220ms CPU time
Info::
https://www.googletagmanager.com/gtag/js?id=G-VPW5...: 97ms CPU time
Info::
Unattributable: 72ms CPU time
Warning::
Third-party scripts: 389ms (100% of total)

Main Thread Breakdown

Script Evaluation 35% Style & Layout 26% Other 20% Parse HTML & CSS 9% Script Parsing & Compilation 6% Rendering 4%
ScriptTotalScriptingParse/CompileParty
https://www.city-data.com/220ms12ms12ms3rd
https://www.googletagmanager.com/gtag/js?id=G-VPW5MZTH4E97ms84ms12ms3rd
Unattributable72ms6ms0ms3rd
A+
Font Loading
6 fonts (14 KB)
PASS
6 fonts (14 KB)
Info::
6 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

6

14 KB total

Render-blocking

0

of 6

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 1.3 s LCP 1.3 shttps://pics3.city-data.com/fonts/glyphicons-halflings-regular.woff2glyphicons-halflings-re... https://pics3.city-data.com/fonts/glyphicons-halflings-regular.woff2 — 0 B — 25 ms — font-display: swaphttps://pics3.city-data.com/fonts/city-data.woff?73345346city-data.woff https://pics3.city-data.com/fonts/city-data.woff?73345346 — 0 B — 27 ms — font-display: swaphttps://fonts.gstatic.com/s/opensans/v15/mem8YaGs126MiZpBA-UFVZ0b.woff2mem8YaGs126MiZpBA-UFVZ0... https://fonts.gstatic.com/s/opensans/v15/mem8YaGs126MiZpBA-UFVZ0b.woff2 — 13.7 KiB — 41 ms — font-display: swaphttps://pics3.city-data.com/fonts/city-data.ttf?73345346city-data.ttf https://pics3.city-data.com/fonts/city-data.ttf?73345346 — 0 B — 60 ms — font-display: swaphttps://pics3.city-data.com/fonts/glyphicons-halflings-regular.woffglyphicons-halflings-re... https://pics3.city-data.com/fonts/glyphicons-halflings-regular.woff — 0 B — 57 ms — font-display: swaphttps://pics3.city-data.com/fonts/glyphicons-halflings-regular.ttfglyphicons-halflings-re... https://pics3.city-data.com/fonts/glyphicons-halflings-regular.ttf — 0 B — 46 ms — font-display: swap
glyphicons-halflings-re... woff2 swap
Size 0 KB
Load time 25 ms
Start 368 ms
Risk FOUT — text flashes from fallback to web font
city-data.woff woff swap
Size 0 KB
Load time 27 ms
Start 369 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
mem8YaGs126MiZpBA-UFVZ0... woff2 swap
Size 14 KB
Load time 41 ms
Start 378 ms
Risk FOUT — text flashes from fallback to web font
city-data.ttf ttf swap
Size 0 KB
Load time 60 ms
Start 597 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
glyphicons-halflings-re... woff swap
Size 0 KB
Load time 57 ms
Start 601 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
glyphicons-halflings-re... ttf swap
Size 0 KB
Load time 46 ms
Start 657 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)
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
25 resources · 568 KB · 60 KB savings available
PASS
25 resources · 568 KB · 60 KB savings available
Info::
Within 1MB page-weight target
Got: 568 KB
Info::
~60 KB of savings available
Warning::
24 third-party resources (100% of weight)
Info::
1 resources over 200KB
25 resources · 568.3 KiB · 24 third-party Within 1MB page-weight target
JavaScript 54% · 304.7 KiB
Document 41% · 231.8 KiB
Image 3% · 16.8 KiB
Font 2% · 13.7 KiB
Other 0% · 1.3 KiB
CSS 0% · 0 B

~60.1 KiB of savings available

Remove unused JavaScript: 60.1 KiB
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: OVHcloud

Network Waterfall
25 requests over 946ms
INFO
0 ms 500 ms 1.0 s FCP 1.3 s LCP 1.3 shttps://city-data.com// https://city-data.com/ — 301 — 136 B — 193 ms — h2https://www.city-data.com/www.city-data.com/ https://www.city-data.com/ — 200 — 231.7 KiB — 301 ms — h2https://pics3.city-data.com/fonts/glyphicons-halflings-regular.woff2pics3.city-data.com/fonts/glyphicon... https://pics3.city-data.com/fonts/glyphicons-halflings-regular.woff2 — -1 — 0 B — 25 ms — https://pics3.city-data.com/fonts/city-data.woff?73345346pics3.city-data.com/fonts/city-data... https://pics3.city-data.com/fonts/city-data.woff?73345346 — -1 — 0 B — 27 ms — https://pics3.city-data.com/assets/desktop/maps/states_bg.pngpics3.city-data.com/assets/desktop/... https://pics3.city-data.com/assets/desktop/maps/states_bg.png — -1 — 0 B — 27 ms — https://pics3.city-data.com/assets/desktop/bg/1background.jpgpics3.city-data.com/assets/desktop/... https://pics3.city-data.com/assets/desktop/bg/1background.jpg — -1 — 0 B — 32 ms — https://pics3.city-data.com/css/bootstrap.min.csspics3.city-data.com/css/bootstrap.m... https://pics3.city-data.com/css/bootstrap.min.css — -1 — 0 B — 27 ms — https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.jsajax.googleapis.com/ajax/libs/jquer... https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js — 200 — 33.8 KiB — 74 ms — h2https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/js/bootstrap.min.jsmaxcdn.bootstrapcdn.com/bootstrap/3... https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/js/bootstrap.min.js — 200 — 10.1 KiB — 32 ms — h3https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.jspagead2.googlesyndication.com/pagea... https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js — 200 — 54.3 KiB — 61 ms — h3https://www.google-analytics.com/ga.jswww.google-analytics.com/ga.js https://www.google-analytics.com/ga.js — 200 — 17.4 KiB — 38 ms — h2https://fonts.gstatic.com/s/opensans/v15/mem8YaGs126MiZpBA-UFVZ0b.woff2fonts.gstatic.com/s/opensans/v15/me... https://fonts.gstatic.com/s/opensans/v15/mem8YaGs126MiZpBA-UFVZ0b.woff2 — 200 — 13.7 KiB — 41 ms — h3https://www.googletagmanager.com/gtag/js?id=G-VPW5MZTH4Ewww.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=G-VPW5MZTH4E — 200 — 153.2 KiB — 101 ms — h2https://secure.quantserve.com/quant.jssecure.quantserve.com/quant.js https://secure.quantserve.com/quant.js — 200 — 12.2 KiB — 21 ms — h2https://www.city-data.com/a/util.jswww.city-data.com/a/util.js https://www.city-data.com/a/util.js — 200 — 23.5 KiB — 161 ms — h2data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAWcAAAA8CAYAAAC6hnsNAAAf+ElEQVR4Ae3cZ7icZYH/8c/9PM/Mn…data:image/png;base64,iVBORw0KGgoAA... data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAWcAAAA8CAYAAAC6hnsNAAAf+ElEQVR4Ae3cZ7icZYH/8c/9PM/Mn… — 200 — 0 B — 0 ms — datahttps://pics3.city-data.com/fonts/city-data.ttf?73345346pics3.city-data.com/fonts/city-data... https://pics3.city-data.com/fonts/city-data.ttf?73345346 — -1 — 0 B — 60 ms — https://pics3.city-data.com/fonts/glyphicons-halflings-regular.woffpics3.city-data.com/fonts/glyphicon... https://pics3.city-data.com/fonts/glyphicons-halflings-regular.woff — -1 — 0 B — 57 ms — https://www.city-data.com/js/cookie_notifier_js.phpwww.city-data.com/js/cookie_notifie... https://www.city-data.com/js/cookie_notifier_js.php — 200 — 242 B — 75 ms — h3https://pics3.city-data.com/fonts/glyphicons-halflings-regular.ttfpics3.city-data.com/fonts/glyphicon... https://pics3.city-data.com/fonts/glyphicons-halflings-regular.ttf — -1 — 0 B — 46 ms — https://www.city-data.com/a/util.php?action_name=City-Data.com%20-%20Stats%20about%20all%20US%20cities%20-%20real%20estate%2C%20relocation%20info%2C%20crime%2C%20house%20prices%2C%20cost%20of%20living%2C%20races%2C%20home%20value%20estimator%2C%20recent%20sales%2C%20income%2C%20photos%2C%20schools%2C%20maps%2C%20weather%2C%20neighborhoods%2C%20and%20more&idsite=1&rec=1&r=044457&h=22&m=36&s=25&url=https%3A%2F%2Fwww.city-data.com%2F&_id=70b968ac252cf817&_idn=1&send_image=0&_refts=0&pv_id=VSLC5q&devicePixelRatio=1&pf_net=0&pf_srv=99&pf_tfr=196&pf_dm1=330&uadata=%7B%22formFactors%22%3A%5B%22Desktop%22%5D%2C%22fullVersionList%22%3A%5B%7B%22brand%22%3A%22Not-A.Brand%22%2C%22version%22%3A%2224.0.0.0%22%7D%2C%7B%22brand%22%3A%22Chromium%22%2C%22version%22%3A%22146.0.7680.164%22%7D%5D%2C%22mobile%22%3Afalse%2C%22model%22%3A%22%22%2C%22platform%22%3A%22macOS%22%2C%22platformVersion%22%3A%2210.15.7%22%7D&pdf=1&qt=0&realp=0&wma=0&fla=0&java=0&ag=0&cookie=1&res=800x600www.city-data.com/a/util.php?action... https://www.city-data.com/a/util.php?action_name=City-Data.com%20-%20Stats%20about%20all%20US%20cities%20-%20real%20estate%2C%20relocation%20info%2C%20crime%2C%20house%20prices%2C%20cost%20of%20living%2C%20races%2C%20home%20value%20estimator%2C%20recent%20sales%2C%20income%2C%20photos%2C%20schools%2C%20maps%2C%20weather%2C%20neighborhoods%2C%20and%20more&idsite=1&rec=1&r=044457&h=22&m=36&s=25&url=https%3A%2F%2Fwww.city-data.com%2F&_id=70b968ac252cf817&_idn=1&send_image=0&_refts=0&pv_id=VSLC5q&devicePixelRatio=1&pf_net=0&pf_srv=99&pf_tfr=196&pf_dm1=330&uadata=%7B%22formFactors%22%3A%5B%22Desktop%22%5D%2C%22fullVersionList%22%3A%5B%7B%22brand%22%3A%22Not-A.Brand%22%2C%22version%22%3A%2224.0.0.0%22%7D%2C%7B%22brand%22%3A%22Chromium%22%2C%22version%22%3A%22146.0.7680.164%22%7D%5D%2C%22mobile%22%3Afalse%2C%22model%22%3A%22%22%2C%22platform%22%3A%22macOS%22%2C%22platformVersion%22%3A%2210.15.7%22%7D&pdf=1&qt=0&realp=0&wma=0&fla=0&java=0&ag=0&cookie=1&res=800x600 — 204 — 197 B — 81 ms — h3https://analytics.google.com/g/collect?v=2&tid=G-VPW5MZTH4E&gtm=45je64k1v9131902819za200zd9131902819&_p=1776897385061&_gaz=1&gcd=13l3l3l3l1l1&npa=0&dma=0&_eu=AAAAAGA&are=1&cid=323182487.1776897385&frm=0&pscdl=noapi&rcb=7&sr=800x600&uaa=x86&uab=64&uafvl=Not-A.Brand%3B24.0.0.0%7CChromium%3B146.0.7680.164&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115616985~115938466~115938468~117266401~117512543~118128923&sid=1776897385&sct=1&seg=0&dl=https%3A%2F%2Fwww.city-data.com%2F&dt=City-Data.com%20-%20Stats%20about%20all%20US%20cities%20-%20real%20estate%2C%20relocation%20info%2C%20crime%2C%20house%20prices%2C%20cost%20of%20living%2C%20races%2C%20home%20value%20estimator%2C%20recent%20sales%2C%20income%2C%20photos%2C%20schools%2C%20maps%2C%20weather%2C%20neighborhoods%2C%20and%20more&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=770analytics.google.com/g/collect?v=2&... https://analytics.google.com/g/collect?v=2&tid=G-VPW5MZTH4E&gtm=45je64k1v9131902819za200zd9131902819&_p=1776897385061&_gaz=1&gcd=13l3l3l3l1l1&npa=0&dma=0&_eu=AAAAAGA&are=1&cid=323182487.1776897385&frm=0&pscdl=noapi&rcb=7&sr=800x600&uaa=x86&uab=64&uafvl=Not-A.Brand%3B24.0.0.0%7CChromium%3B146.0.7680.164&uam=&uamb=0&uap=macOS&uapv=10.15.7&uaw=0&ul=en-us&_s=1&tag_exp=0~115616985~115938466~115938468~117266401~117512543~118128923&sid=1776897385&sct=1&seg=0&dl=https%3A%2F%2Fwww.city-data.com%2F&dt=City-Data.com%20-%20Stats%20about%20all%20US%20cities%20-%20real%20estate%2C%20relocation%20info%2C%20crime%2C%20house%20prices%2C%20cost%20of%20living%2C%20races%2C%20home%20value%20estimator%2C%20recent%20sales%2C%20income%2C%20photos%2C%20schools%2C%20maps%2C%20weather%2C%20neighborhoods%2C%20and%20more&en=page_view&_fv=1&_nsi=1&_ss=1&_ee=1&tfd=770 — 204 — 550 B — 77 ms — h2https://stats.g.doubleclick.net/g/collect?v=2&tid=G-VPW5MZTH4E&cid=323182487.1776897385&gtm=45je64k1v9131902819za200zd9131902819&rcb=7&aip=1&dma=0&gcd=13l3l3l3l1l1&npa=0&frm=0&tag_exp=0~115616985~115938466~115938468~117266401~117512543~118128923stats.g.doubleclick.net/g/collect?v... https://stats.g.doubleclick.net/g/collect?v=2&tid=G-VPW5MZTH4E&cid=323182487.1776897385&gtm=45je64k1v9131902819za200zd9131902819&rcb=7&aip=1&dma=0&gcd=13l3l3l3l1l1&npa=0&frm=0&tag_exp=0~115616985~115938466~115938468~117266401~117512543~118128923 — 204 — 550 B — 65 ms — h2https://www.city-data.com/favicon.icowww.city-data.com/favicon.ico https://www.city-data.com/favicon.ico — 200 — 16.8 KiB — 135 ms — h3data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxj…data:image/png;base64,iVBORw0KGgoAA... data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxj… — 200 — 0 B — 0 ms — data
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 389ms · 385KB · €4/mo
www.city-data.com
Other
Costly
Execution 220ms
Transfer 232 KB
Monthly Cost €2/mo
Google Tag Manager
Tag Manager
Optional
Execution 97ms
Transfer 153 KB
Unused 39%
Monthly Cost €1/mo
Unattributable
Other
Optional
Execution 72ms
Transfer 0 KB
Monthly Cost €1/mo

These scripts may cost more than they're worth

  • www.city-data.com adds 220ms and costs ~€2/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.city-data.com takes 220ms 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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