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21.co.uk

https://21.co.uk· First analyzed 07 May 2026· Updated 07 May 2026
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21.co.uk
Desktop screenshot of 21.co.uk
Mobile screenshot of 21.co.uk
Mobile

Sponsored

Hosting Provider

Incapsula Inc

IP Address

107.154.133.67

Site Location

🇬🇧 United Kingdomvia tld

Server Location

🇺🇸 New York, United States

ASN

AS19551

Organization

Incapsula Inc

Server

Nginx

CDN

CDN

Nameservers

b.portsdns.net.a.portsdns.se.

Performance

100

Core Web Vitals

Weight

First Contentful Paint
339 ms10%
Speed Index
441 ms10%
Largest Contentful Paint
—25%
Total Blocking Time
0.0 ms30%
Cumulative Layout Shift
0.00025%
207 KB
17 requests

Image Optimization

Lazy LoadResponsive
0–49
50–89
90–100

Architecture Stack

Hybrid
🔀 Hybrid
Frontend
Framework
Next.js
Infrastructure
Hosting
Incapsula Inc
CDN
CDN

Progressive Web App

Web ManifestApple Touch IconTheme Color

Technology Stack

5 Technologies Detected

CSS Frameworks

2
Tailwind CSS
Material UI

Meta Frameworks

1
Next.jsv23.14.24

Tag Managers

1
Google Tag Manager

Web Servers

1
Nginx

SEO Analysis

B72/100
22
4
0
Meta Tags15/15
Content8/12
Headings8/8
Technical16/25
E-E-A-T0/7
Images6/7
Links2/5
URL5/5
Social5/5
Freshness0/4
Mobile4/4
Indexability3/3
2
21.co.uk21.co.uk

Top UK Casino Online | Play Online Casino Games at 21.co.uk

With over 2,000 online casino games on 21.co.uk, we have an incredible selection of the newest and best UK casino games!

Title Length59 chars

Recommended: 50-60 chars (~352px / 580px)

Description Length120 chars

Recommended: 120-160 chars

Issues (0)

    4 issues found

    Upgrade to view details

    Crawlability

    Sitemap

    Type: standard

    3,987 URLs

    robots.txt

    9 rules

    Sitemap reference found

    Local SEO

    Local Search Readiness

    3/100
    Poor
    1 14 2

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

    Sponsored

    AI & LLM Readiness

    F38/100
    Bot Access
    20/25
    Machine Read.
    7/25
    Schema Data
    0/25
    Citation
    11/25

    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
    Text ratio:1%
    Words:2,499
    Token eff.:Optimal

    Structured Data

    No Schema

    Citation Readiness

    Opening Summary65w
    Descriptive Headings
    Canonical URL
    Open Graph2/3
    Twitter Card3/3
    Language Tag
    Publish Date
    Author Info
    Lists
    Tables
    TL;DR / Summary
    About Page Link
    Recommendations (11)
    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
    20/20
    Checks if images have descriptive alt text for screen readers and visually impaired users.
    Semantic Structure
    13/20
    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
    7/15
    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.
    66/100
    A+
    26 mg
    CO₂e / view
    206.8 KB
    Page Weight
    95%
    Cleaner Than
    New Visitor
    29 mg
    vs
    Returning (cached)
    15 mg
    Annual (10K/mo)
    3.1 kg
    Emission Segments
    Data Center
    6 mg
    Network
    6 mg
    Device
    14 mg
    Resource Breakdown
    Images
    94.1 KB
    HTML
    112.7 KB
    Green Hosting Not Verified
    Incapsula Inc
    4 recommendations
    • •Carbon footprint recommendation preview...
    Upgrade to view recommendations
    B

    Security Score

    71%Good
    Interactive

    HTTPS

    WAF

    107d

    Certificate Details

    Type

    Organization Validated (OV)

    Certificate Authority

    DigiCert Inc

    Key Algorithm

    RSA (2048 bit)

    Signature

    SHA-256 with RSA

    TLS Version

    TLSv1.3

    HTTP Protocol

    HTTP/2

    Valid From

    22.07.2025

    Valid Until

    22.08.2026

    OCSP Stapling

    Enabled

    Subject Alternative Names (2)

    *.21.co.uk21.co.uk

    SHA-256 Fingerprint

    A3:1B:E6:FA:F0:51:87:3D:80:7B:6A:B8:66:16:2F:D6:2B:D6:9E:B9...

    Top Recommendations

    Security recommendation preview

    Upgrade to view recommendations
    Upgrade to view header details

    HTTP Headers

    Developer Console

    cache-control
    🔴 No Cache(private, no-cache, no-store, max-age=0, must-revalidate)
    content-encoding
    📦 Gzip(gzip)
    content-security-policy
    frame-ancestors 'self' *.leovegas.com *.casinomodule.com *.y...
    content-type
    text/html; charset=utf-8
    date
    Thu, 07 May 2026 00:27:40 GMT
    etag
    W/"dznizv288ts9az"
    Good Warning Issue

    Email Infrastructure

    Google Workspace

    Score

    95

    SPF
    DKIM
    DMARC

    DMARC Policy

    Reject (Strictest)

    MX Records (6)

    ASPMX.L.GOOGLE.COM
    mail.21.co.uk
    ALT1.ASPMX.L.GOOGLE.COM
    ASPMX3.GOOGLEMAIL.COM

    +2 more

    Domain Information

    21.co.uk

    Domain Age
    28y 9m

    Created

    25.07.1997

    Expires

    25.07.2026

    Last Updated

    18.07.2025

    Registrar

    Abion AB

    DNSSEC
    Not Enabled

    Privacy & Compliance

    Cookie Consent Banner
    Privacy Policy
    Terms of Service

    GDPR Indicators

    Cookie consent banner detected
    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.
    B
    78/100
    Mobile Friendly137 breakpoints
    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
    minimum-scale=1, initial-scale=1, width=device-width, shrink-to-fit=no, interactive-widget=resizes-content
    1 recommendation
    • •Mobile compatibility recommendation preview...
    Upgrade to view recommendations

    Typography & Readability

    Montserrat

    WCAG Partial
    75/100
    Readability
    /30
    24/30

    16px · LH 1.50

    Hierarchy
    /20
    19/20

    2.12x ratio · ✓ H1→H6

    WCAG
    /25
    16/25

    1:1 min contrast

    Performance
    /25
    16/25

    1 font

    Heading Font

    Montserrat

    Sans34px

    Body Font

    Montserrat

    Sans16px

    Contrast Ratio

    1:1

    34 issues

    Reading Comfort

    ~40 CPL

    Narrow lines
    34px
    h1
    25px
    h2
    48px
    h3
    34px
    h4
    16px
    p

    ✅ Excellent readability: 16px body text is ideal for all devices.

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

    ⚠️ Partial contrast: 34 elements below WCAG AA threshold (min 1.0:1).

    ✅ Perfect heading hierarchy: Sequential h1→h2→h3 with single H1 — ideal for SEO & accessibility.

    ✅ Strong hierarchy: Headlines are 2.1x larger than body text.

    ✅ Lean font stack: 1 font families keeps load times fast.

    Buy on MyFontsFlesch 56

    Color Palette

    5 unique colors
    2.36:1 Fail Dark
    #000000
    Primary· 66.30000000000001%
    #404d43
    Secondary· 4.6%
    #130e0b
    Secondary· 13.7%
    #383124
    Secondary· 9.7%
    #2d1f13
    Secondary· 5.9%

    Business & Marketing Stack

    2 Tools Detected

    Growing

    Behavior Analytics

    2
    Google Tag ManagerFree
    Google AnalyticsFree

    User behavior and product analytics

    1

    Categories

    2

    Total Tools

    0

    Enterprise

    0

    Mid-Market

    Assessment: Growing marketing technology adoption

    Sponsored

    Scripts & Styles

    20 Resources

    20
    Scripts
    0
    Styles
    0
    Async
    20
    Defer

    Top Script Sources

    cdn.21.co.uk(20)

    Website Identity

    21.co.uk

    28 years old
    Location detected: 🇬🇧 United Kingdomvia tld
    Abion AB📧 Google Workspaceen

    Sponsored

    Last analyzed: 07 May 2026 at 00:28

    Historical Analysis & Change Tracking