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c21.com

https://c21.com· First analyzed 15 May 2026· Updated 15 May 2026
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c21.com
Desktop screenshot of c21.com
Mobile screenshot of c21.com
Mobile

Sponsored

Hosting Provider

Amazon Web Services (AWS)
aws.amazon.com

IP Address

18.222.36.97

Site Location

🇺🇸 United Statesvia ip

Server Location

🇺🇸 Dublin, United States

ASN

AS16509

Organization

AWS EC2 (us-east-2)

Server

AmazonS3

CDN

CloudFront

Nameservers

ns-1619.awsdns-10.co.uk.ns-236.awsdns-29.com.ns-788.awsdns-34.net.ns-1182.awsdns-19.org.

Performance

95

Core Web Vitals

Weight

First Contentful Paint
1.1 s10%
Speed Index
1.5 s10%
Largest Contentful Paint
—25%
Total Blocking Time
0.0 ms30%
Cumulative Layout Shift
0.00025%
2.1 MB
108 requests

Image Optimization

WebP
0–49
50–89
90–100

Architecture Stack

Monolithic
⚙️ SSR
Infrastructure
Platform
AWS CloudFront
CDN
CloudFront

Technology Stack

7 Technologies Detected

Analytics

3
Google Analytics
Google Analytics 4
Facebook Pixel

CSS Frameworks

1
Tailwind CSS

Icon Libraries

1
Font Awesome

Tag Managers

1
Google Tag Manager

Advertising

1
Google Ads

SEO Analysis

B71/100
20
5
0
Meta Tags15/15
Content9/12
Headings6/8
Technical16/21
E-E-A-T0/7
Images3/7
Links5/5
URL5/5
Social5/5
Freshness0/4
Mobile4/4
Indexability3/3
C
c21.comc21.com

CENTURY 21 | Your Next Home's Here- Let Our Agents Help

Find your next home with CENTURY 21. Browse updated MLS listings and connect with expert agents ready to guide your search.

Title Length55 chars

Recommended: 50-60 chars (~337px / 580px)

Description Length123 chars

Recommended: 120-160 chars

Issues (0)

    5 issues found

    Upgrade to view details

    Local SEO

    Local Search Readiness

    15/100
    Poor
    4 11 2

    This site doesn't appear to be a local business. Local SEO signals are optional for non-local websites.

    Sponsored

    AI & LLM Readiness

    D54/100
    Bot Access
    20/25
    Machine Read.
    13/25
    Schema Data
    6/25
    Citation
    15/25

    AI Bot Access

    14/14 accessible
    AI Search
    OAI-SearchBot
    PerplexityBot
    Claude-SearchBot
    Gemini-Deep-Research
    DuckAssistBot
    Training
    GPTBot
    ClaudeBot
    Google-Extended
    Meta-ExternalAgent
    Bytespiderinfo
    Amazonbot
    Applebot-Extended
    CCBotinfo
    Fetch
    ChatGPT-User

    Machine Readability

    llms.txt
    llms-full.txt
    Semantic HTML
    Heading Hierarchy
    nav
    Text ratio:6%
    Words:870
    Token eff.:Optimal
    Sections/1K:13.8
    Depth:1/5

    Structured Data

    1 JSON-LD
    Organization×1.1WebSite
    sameAs entity links

    Citation Readiness

    Opening Summary37w
    Descriptive Headingsavg 6w
    Canonical URL
    Open Graph3/3
    Twitter Card2/3
    Language Tag
    Publish Date
    Author Info
    Lists
    Tables
    TL;DR / Summary
    About Page Link
    Recommendations (6)
    AI readiness recommendation preview...
    Upgrade to view recommendations

    Sponsored

    Accessibility

    WCAG 2.1 Compliance

    Evaluates how accessible your website is for users with disabilities, based on WCAG 2.1 guidelines. Checks images, forms, keyboard navigation, ARIA roles, and color contrast.
    B
    76/100
    11
    Passed
    4
    Critical
    0
    Warnings
    Images & Alt Text
    13/20
    Checks if images have descriptive alt text for screen readers and visually impaired users.
    Semantic Structure
    18/20
    Evaluates proper use of HTML5 semantic elements (header, nav, main, footer) and heading hierarchy.
    Forms & Inputs
    15/15
    Verifies form fields have labels, error messages are clear, and inputs are properly associated.
    Color & Contrast
    15/15
    Tests text-to-background color contrast ratios against WCAG AA/AAA minimum requirements.
    Keyboard & Focus
    9/15
    Ensures all interactive elements are reachable and operable via keyboard (tab, enter, escape).
    ARIA & Roles
    6/15
    Checks correct use of WAI-ARIA attributes (roles, states, properties) for assistive technologies.
    2 recommendations
    • •Accessibility recommendation preview...
    Upgrade to view recommendations

    Carbon Footprint

    SWDM v4 · Eco-Score

    Carbon emissions estimated using the Sustainable Web Design Model v4 (SWDM v4). Factors in data center, network, and device energy across new and returning visitors. Grade thresholds based on HTTP Archive percentiles.
    53/100
    D
    214 mg
    CO₂e / view
    2.1 MB
    Page Weight
    50%
    Cleaner Than
    New Visitor
    245 mg
    vs
    Returning (cached)
    122 mg
    Annual (10K/mo)
    25.7 kg
    Emission Segments
    Data Center
    11 mg
    Network
    63 mg
    Device
    141 mg
    Resource Breakdown
    JavaScript
    836.9 KB
    Images
    432.0 KB
    CSS
    748.5 KB
    Fonts
    96.2 KB
    HTML
    1.1 KB
    Other
    4.4 KB
    Green Hosting Verified
    Amazon Web Services (AWS)
    Provider Match
    4 recommendations
    • •Carbon footprint recommendation preview...
    Upgrade to view recommendations
    F

    Security Score

    26%Critical
    Interactive

    HTTPS

    WAF

    116d

    Certificate Details

    Type

    Domain Validated (DV)

    Certificate Authority

    Amazon

    Key Algorithm

    RSA (2048 bit)

    Signature

    SHA-256 with RSA

    TLS Version

    TLSv1.3

    HTTP Protocol

    HTTP/2+H3

    Valid From

    23.02.2026

    Valid Until

    08.09.2026

    OCSP Stapling

    Enabled

    Subject Alternative Names (2)

    www.century21.com*.www.century21.com

    SHA-256 Fingerprint

    67:88:1A:45:26:DA:F3:4B:F8:50:0D:FA:15:9F:77:72:D8:D0:A8:67...

    Top Recommendations

    Security recommendation preview

    Upgrade to view recommendations
    Upgrade to view header details

    HTTP Headers

    Developer Console

    alt-svc
    h3=":443"; ma=86400
    cache-control
    🔵 1 Week(public, max-age=604800)
    content-encoding
    ⚡ Brotli(br)
    content-type
    text/html
    date
    Fri, 15 May 2026 23:04:25 GMT
    etag
    W/"61180cdd6459308db6275a092fe76441"
    Good Warning Issue

    Email Infrastructure

    Mimecast

    Score

    90

    SPF
    DKIM
    DMARC

    DMARC Policy

    None (Monitor Only)

    MX Records (2)

    usb-smtp-inbound-2.mimecast.com
    usb-smtp-inbound-1.mimecast.com

    Domain Information

    c21.com

    Domain Age
    31y 2m

    Created

    10.03.1995

    Expires

    11.03.2027

    Last Updated

    08.03.2026

    Registrar

    CSC Corporate Domains, Inc.

    DNSSEC
    Not Enabled

    Privacy & Compliance

    TrustArc

    Cookie Consent Banner
    TrustArc
    Privacy Policy
    Terms of Service

    GDPR Indicators

    Cookie consent banner detected
    CMP: TrustArc
    Privacy policy page linked

    Mobile Compatibility

    Viewport & Responsive Test

    Tests how well your website works on mobile devices. Checks viewport configuration, responsive layout, touch targets, font readability, and simulates rendering across different screen sizes.
    C
    65/100
    Mobile Friendly1 breakpoint
    Viewport Meta
    The viewport meta tag tells mobile browsers how to scale the page. Without it, mobile devices render at desktop width.
    Responsive Design
    Uses CSS media queries or flexible layouts to adapt content to different screen sizes automatically.
    Touch Icons
    Apple touch icons and favicons displayed when users add the site to their home screen on mobile devices.
    Readable Font Size
    Base font size should be at least 16px on mobile to ensure text is readable without zooming.
    Relative Units
    Using em, rem, %, or vw instead of fixed px values allows content to scale properly across screen sizes.
    No H-Scroll Risk
    No elements wider than the viewport that would cause horizontal scrolling on mobile devices.
    Tap Targets OK
    Interactive elements (buttons, links) are at least 48x48px with enough spacing to prevent accidental taps.
    No Fixed Widths
    No elements with fixed pixel widths that could overflow on smaller screens and break the layout.
    Viewport
    width=device-width, initial-scale=1.0
    1 recommendation
    • •Mobile compatibility recommendation preview...
    Upgrade to view recommendations

    Typography & Readability

    Bold + Regular

    WCAG AA
    68/100
    Readability
    /30
    14/30

    12px · LH 1.50

    Hierarchy
    /20
    15/20

    4.67x ratio

    WCAG
    /25
    21/25

    6.13:1 min contrast

    Performance
    /25
    18/25

    2 fonts · 4 req

    Heading Font

    Bold

    Sans56px

    Body Font

    Regular

    Sans12px

    Contrast Ratio

    6.13:1

    WCAG AA (≥4.5:1)

    Reading Comfort

    ~41 CPL

    Narrow lines
    56px
    h1
    32px
    h2
    15px
    h3
    12px
    p

    ❌ Critical: 12px body text is too small. Minimum 14px, recommend 16px+.

    ✅ Optimal line spacing: 1.50 ratio (ideal range 1.4–1.6).

    ✅ WCAG AA contrast: All text meets 4.5:1 ratio (min 6.1:1).

    ⚠️ Minor heading issue: 0 level skip(s) detected. Maintain sequential order for screen readers.

    ✅ Strong hierarchy: Headlines are 4.7x larger than body text.

    ✅ Lean font stack: 2 font families keeps load times fast.

    Buy on MyFontsFlesch 52

    Color Palette

    10 unique colors
    16.14:1 AAA Light
    #fcfcfc
    Background· 20.5%
    #1e1f1c
    Primary· 10.9%
    #eaecee
    Secondary· 3.4%
    #758692
    Secondary· 1.9%

    Business & Marketing Stack

    5 Tools Detected

    Enterprise

    Behavior Analytics

    2
    Google Tag ManagerFree
    Google AnalyticsFree

    User behavior and product analytics

    Advertising

    3
    Google AdsEnterprise
    Facebook PixelMid-Market
    AdRollMid-Market

    Ad platforms and retargeting pixels

    2

    Categories

    5

    Total Tools

    1

    Enterprise

    2

    Mid-Market

    Assessment: Sophisticated marketing and sales technology infrastructure

    Sponsored

    Scripts & Styles

    30 Resources

    20
    Scripts
    10
    Styles
    13
    Async
    1
    Defer

    Top Script Sources

    googletagmanager.com(4)maps.googleapis.com(4)s.adroll.com(3)connect.facebook.net(2)googleads.g.doubleclick.net(2)

    Website Identity

    c21.com

    31 years old
    Location detected: 🇺🇸 United Statesvia ip
    CSC Corporate Domains, Inc.📧 Mimecasten

    Sponsored

    Last analyzed: 15 May 2026 at 23:04

    Historical Analysis & Change Tracking