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zdb-katalog.de

https://zdb-katalog.de· First analyzed 05 May 2026· Updated 05 May 2026
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zdb-katalog.de
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Mobile

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Hosting Provider

Deutsche Nationalbibliothek, Bibliothek Frankfurt, Deutsche Buecherei Leipzig, Deutsches Musikarchiv Berlin

IP Address

193.175.100.229

Site Location

🇩🇪 Germanyvia tld

Server Location

🇩🇪 Frankfurt am Main, Germany

ASN

AS680

Organization

Deutsche Nationalbibliothek, Bibliothek Frankfurt, Deutsche Buecherei Leipzig, Deutsches Musikarchiv Berlin

Server

Apache

Nameservers

ns1.dnb.de.dns-1.dfn.de.ns0.dnb.de.

Performance

91

Core Web Vitals

Weight

First Contentful Paint
1.4 s10%
Speed Index
1.8 s10%
Largest Contentful Paint
—25%
Total Blocking Time
0.0 ms30%
Cumulative Layout Shift
0.00025%
1.8 MB
37 requests
0–49
50–89
90–100

Architecture Stack

Monolithic
⚙️ SSR
Infrastructure
Hosting
Deutsche Nationalbibliothek, Bibliothek Frankfurt, Deutsche Buecherei Leipzig, Deutsches Musikarchiv Berlin

Technology Stack

3 Technologies Detected

Libraries

1
jQuery

CSS Frameworks

1
Tailwind CSS

Web Servers

1
Apache

SEO Analysis

D56/100
15
9
0
Meta Tags5/15
Content11/12
Headings6/8
Technical13/25
E-E-A-T0/7
Images4/7
Links5/5
URL5/5
Social0/5
Freshness0/4
Mobile4/4
Indexability3/3
Z
zdb-katalog.dezdb-katalog.de

ZDB catalogue - Home

ZDB Magazines Database

Title Length20 chars

Recommended: 50-60 chars (~124px / 580px)

Description Length22 chars

Recommended: 120-160 chars

Issues (0)

    9 issues found

    Upgrade to view details

    Crawlability

    Sitemap
    robots.txt

    32 rules

    Local SEO

    Local Search Readiness

    6/100
    Poor
    2 13 2

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

    Sponsored

    AI & LLM Readiness

    D40/100
    Bot Access
    20/25
    Machine Read.
    11/25
    Schema Data
    0/25
    Citation
    9/25

    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:10%
    Words:1,505
    Token eff.:Optimal
    Sections/1K:0.7

    Structured Data

    No Schema

    Citation Readiness

    Opening Summary48w
    Descriptive Headingsavg 3.5w
    Canonical URL
    Open Graph0/3
    Twitter Card0/3
    Language Tag
    Publish Date
    Author Info
    Lists
    Tables
    TL;DR / Summary
    About Page Link
    Recommendations (10)
    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.
    C
    69/100
    11
    Passed
    4
    Critical
    2
    Warnings
    Images & Alt Text
    20/20
    Checks if images have descriptive alt text for screen readers and visually impaired users.
    Semantic Structure
    12/20
    Evaluates proper use of HTML5 semantic elements (header, nav, main, footer) and heading hierarchy.
    Forms & Inputs
    2/15
    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
    11/15
    Ensures all interactive elements are reachable and operable via keyboard (tab, enter, escape).
    ARIA & Roles
    9/15
    Checks correct use of WAI-ARIA attributes (roles, states, properties) for assistive technologies.
    2 recommendations
    • •Accessibility recommendation preview...
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    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.
    27/100
    D
    223 mg
    CO₂e / view
    1.8 MB
    Page Weight
    60%
    Cleaner Than
    New Visitor
    255 mg
    vs
    Returning (cached)
    128 mg
    Annual (10K/mo)
    26.8 kg
    Emission Segments
    Data Center
    50 mg
    Network
    54 mg
    Device
    120 mg
    Resource Breakdown
    JavaScript
    1.2 MB
    Images
    103.3 KB
    CSS
    483.3 KB
    HTML
    9.2 KB
    Other
    24.7 KB
    Green Hosting Not Verified
    Deutsche Nationalbibliothek, Bibliothek Frankfurt, Deutsche Buecherei Leipzig, Deutsches Musikarchiv Berlin
    5 recommendations
    • •Carbon footprint recommendation preview...
    Upgrade to view recommendations
    F

    Security Score

    21%Critical
    Interactive

    HTTPS

    No WAF

    64d

    Certificate Details

    Type

    Organization Validated (OV)

    Certificate Authority

    Hellenic Academic and Research Institutions CA

    Key Algorithm

    RSA (4096 bit)

    Signature

    SHA-256 with RSA

    TLS Version

    TLSv1.3

    HTTP Protocol

    HTTP/2

    Valid From

    08.07.2025

    Valid Until

    08.07.2026

    OCSP Stapling

    Enabled

    Subject Alternative Names (1)

    zdb-katalog.de

    SHA-256 Fingerprint

    F9:EF:6C:1B:97:65:A1:77:98:19:FE:2C:A4:45:1B:27:7E:B9:1D:5D...

    Top Recommendations

    Security recommendation preview

    Upgrade to view recommendations
    Upgrade to view header details

    HTTP Headers

    Developer Console

    cache-control
    🔴 No Cache(no-cache, no-store, must-revalidate)
    content-encoding
    📦 Gzip(gzip)
    content-type
    text/html;charset=UTF-8
    date
    Tue, 05 May 2026 01:41:23 GMT
    expires
    Thu, 01 Jan 1970 00:00:00 GMT
    pragma
    no-cache
    Good Warning Issue

    Email Infrastructure

    Custom Mail Server

    Score

    0

    SPF
    DKIM
    DMARC

    Domain Information

    zdb-katalog.de

    Last Updated

    31.08.2022

    DNSSEC
    Not Enabled

    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
    60/100
    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, minimum-scale=1.0, user-scalable=yes
    2 recommendations
    • •Mobile compatibility recommendation preview...
    Upgrade to view recommendations

    Typography & Readability

    Open Sans

    WCAG Partial
    61/100
    Readability
    /30
    19/30

    14px · LH --

    Hierarchy
    /20
    17/20

    2x ratio

    WCAG
    /25
    14/25

    1:1 min contrast

    Performance
    /25
    11/25

    1 font · 4 req

    Heading Font

    Open Sans

    Sans28px

    Body Font

    Open Sans

    Sans14px

    Contrast Ratio

    1:1

    6 issues

    Reading Comfort

    ~47 CPL

    Optimal (45–75)
    28px
    h1
    24px
    h2
    14px
    p

    ⚠️ Small text: 14px may strain on mobile. Use ≥16px for WCAG compliance.

    ✅ Optimal line length: ~47 chars/line (ideal 45–75 CPL).

    ⚠️ Hard to read: Flesch score 31/100. Simplify sentences for wider reach.

    ⚠️ Partial contrast: 6 elements below WCAG AA threshold (min 1.0:1).

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

    ✅ Strong hierarchy: Headlines are 2.0x larger than body text.

    Buy on MyFontsFlesch 31

    Color Palette

    5 unique colors
    Light
    #907983
    Secondary· 3%
    #f4f3f1
    Background· 66.9%
    #c41074
    Primary· 14.599999999999998%
    #371123
    Accent· 8.4%
    #3c3131
    Text· 7.1%

    Sponsored

    Scripts & Styles

    19 Resources

    13
    Scripts
    6
    Styles
    2
    Async
    0
    Defer

    Top Script Sources

    local(10)code.etracker.com(2)etracker.de(1)

    Website Identity

    zdb-katalog.de

    Location detected: 🇩🇪 Germanyvia tld
    en

    Sponsored

    Last analyzed: 05 May 2026 at 01:41

    Historical Analysis & Change Tracking