cerl.org

https://cerl.org· First analyzed 11 May 2026· Updated 11 May 2026

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cerl.org

Mobile

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Hosting Provider

Gemeinsamer Bibiliotheksverbund, Verbundzentrale in Goettingen

IP Address

195.37.138.14

Site Location

🇩🇪 Germanyvia ip

Server Location

🇩🇪 Berlin, Germany

ASN

AS680

Organization

Gemeinsamer Bibiliotheksverbund, Verbundzentrale in Goettingen

Server

Apache

Nameservers

inets1.gbv.de.inets2.gbv.de.

Performance

100

Core Web Vitals

Weight

First Contentful Paint

429 ms10%

Speed Index

558 ms10%

Largest Contentful Paint

—25%

Total Blocking Time

0.0 ms30%

Cumulative Layout Shift

0.00025%

1.4 MB

34 requests

Image Optimization

Lazy Load

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

Gemeinsamer Bibiliotheksverbund, Verbundzentrale in Goettingen

Progressive Web App

Web Manifest

Technology Stack

4 Technologies Detected

CSS Frameworks

Fonts

Web Servers

Languages

SEO Analysis

D56/100

Meta Tags9/15

Content10/12

Headings3/8

Technical12/21

E-E-A-T0/7

Images3/7

Links5/5

URL5/5

Social0/5

Freshness2/4

Mobile4/4

Indexability3/3

cerl.orgcerl.org

Supporting Europe's written heritage [CERL]

No description available for this page.

Title Length43 chars

Recommended: 50-60 chars (~260px / 580px)

Description Length0 chars

Recommended: 120-160 chars

Issues (3)

• Missing meta description — important for click-through rates in SERPs
• Missing H1 tag — every page should have exactly one H1
• Missing viewport meta tag — page may not be mobile-friendly (Google uses mobile-first indexing)

10 issues found

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Local SEO

Local Search Readiness

8/100

Poor

3 12 2

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

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AI & LLM Readiness

F39/100

Bot Access

20/25

Machine Read.

8/25

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:18%

Words:730

Token eff.:Optimal

Sections/1K:6.8

Structured Data

No Schema

Citation Readiness

Opening Summary18w

Descriptive Headingsavg 2.6w

Canonical URL

Open Graph0/3

Twitter Card0/3

Language Tag

Publish Date

Author Info

Lists

Tables

TL;DR / Summary

About Page Link

Recommendations (11)

AI readiness recommendation preview...

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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.

68/100

Passed

Critical

Warnings

Images & Alt Text

20/20

Checks if images have descriptive alt text for screen readers and visually impaired users.

Semantic Structure

7/20

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

4/15

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.

46/100

182 mg

CO₂e / view

1.4 MB

Page Weight

60%

Cleaner Than

New Visitor

209 mg

Returning (cached)

104 mg

Annual (10K/mo)

21.9 kg

Emission Segments

Data Center

41 mg

Network

44 mg

Device

98 mg

Resource Breakdown

JavaScript

370.1 KB

Images

974.7 KB

CSS

87.6 KB

Fonts

1.0 KB

HTML

6.9 KB

Other

35.1 KB

Green Hosting Not Verified

Gemeinsamer Bibiliotheksverbund, Verbundzentrale in Goettingen

4 recommendations

•Carbon footprint recommendation preview...

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Security Score

36%Critical

Interactive

HTTPS

No WAF

61d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Let's Encrypt

Key Algorithm

RSA (4096 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/1.1

Valid From

13.04.2026

Valid Until

12.07.2026

Subject Alternative Names (2)

cerl.orgwww.cerl.org

SHA-256 Fingerprint

FB:23:E5:22:37:A6:4E:63:8B:36:F2:B2:6C:B5:06:07:50:AE:A8:44...

Top Recommendations

Security recommendation preview

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HTTP Headers

Developer Console

cache-control

🔴 No Cache(no-store, no-cache, must-revalidate)

connection

Keep-Alive

content-encoding

📦 Gzip(gzip)

content-type

text/html; charset=utf-8

date

Mon, 11 May 2026 16:25:54 GMT

expires

Thu, 19 Nov 1981 08:52:00 GMT

Good Warning Issue

Email Infrastructure

Microsoft 365

Score

SPF

DKIM

DMARC

MX Records (1)

cerl-org.mail.protection.outlook.com

Domain Information

cerl.org

Domain Age

26y 9m

Created

20.08.1999

Expires

20.08.2026

Last Updated

04.10.2025

Registrar

COREhub, S.R.L.

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Cookie consent banner detected

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.

29/100

Not 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.

4 recommendations

•Mobile compatibility recommendation preview...

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Typography & Readability

Georgia + Arial

WCAG Partial

59/100

Readability

/30

19/30

14px · LH 1.50

Hierarchy

/20

7/20

WCAG

/25

14/25

3:1 min contrast

Performance

/25

19/25

System fonts

Heading Font

Georgia

Serif

Body Font

Arial

Sans14px

Contrast Ratio

3:1

4 issues

Reading Comfort

~92 CPL

Wide lines

22px

19px

14px

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

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

⚠️ Wide lines: ~92 chars/line. Use max-width: 65ch for comfortable reading.

⚠️ Hard to read: Flesch score 39/100. Simplify sentences for wider reach.

⚠️ Partial contrast: 4 elements below WCAG AA threshold (min 3.0:1).

❌ Missing H1: Every page should have exactly one H1 element for SEO and accessibility.

GGoogle Fonts Buy on MyFontsFlesch 39

Color Palette

6 unique colors

2.33:1 Fail Light

#ffffff

Background· 32%

#a3abb0

Secondary· 9.2%

#014165

Primary· 20.3%

#354e69

Secondary· 4.1%

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

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Scripts & Styles

4 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(2)

Website Identity

cerl.org

secretariat@cerl.org

26 years old

Location detected: 🇩🇪 Germanyvia ip

COREhub, S.R.L.📧 Microsoft 365en

Social Profiles

Facebook X (Twitter)

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Last analyzed: 11 May 2026 at 16:26

Historical Analysis & Change Tracking