StackOptic
Back to Search
naturalis.nl favicon

naturalis.nl

https://naturalis.nl· First analyzed 27 Apr 2026· Updated 27 Apr 2026
Export
naturalis.nl
Desktop screenshot of naturalis.nl
Mobile screenshot of naturalis.nl
Mobile

Sponsored

Hosting Provider

True B.V

IP Address

87.233.198.7

Site Location

🇳🇱 Netherlandsvia tld

Server Location

🇳🇱 Amsterdam, The Netherlands

ASN

AS15703

Organization

True B.V

Nameservers

ns-959.awsdns-55.net.ns-117.awsdns-14.com.ns-1282.awsdns-32.org.ns-1805.awsdns-33.co.uk.

Performance

94

Core Web Vitals

Weight

First Contentful Paint
1.2 s10%
Speed Index
1.6 s10%
Largest Contentful Paint
—25%
Total Blocking Time
0.0 ms30%
Cumulative Layout Shift
0.00025%
1.7 MB
65 requests

Image Optimization

Lazy LoadWebPResponsive
0–49
50–89
90–100

Architecture Stack

Monolithic
⚙️ SSR
Infrastructure
Hosting
True B.V

Technology Stack

7 Technologies Detected

Analytics

3
Google Analytics
Google Analytics 4
Facebook Pixel

Libraries

1
jQuery

Other

1
Lottie

CSS Frameworks

1
Tailwind CSS

Tag Managers

1
Google Tag Manager

SEO Analysis

B71/100
20
7
1
Meta Tags12/15
Content11/12
Headings3/8
Technical20/25
E-E-A-T0/7
Images6/7
Links5/5
URL5/5
Social2/5
Freshness0/4
Mobile4/4
Indexability3/3
N
naturalis.nlnaturalis.nl

Naturalis Biodiversity Center | Museum en onderzoek in Leiden

Naturalis Biodiversity Center: voor iedereen die meer wil ontdekken over de rijkdom van de natuur.

Title Length61 chars

Recommended: 50-60 chars (~366px / 580px)

Description Length98 chars

Recommended: 120-160 chars

Issues (1)

  • • Missing H1 tag — every page should have exactly one H1

8 issues found

Upgrade to view details

Crawlability

Sitemap

Type: index

2 URLs

2 sub-sitemaps

robots.txt

33 rules

Local SEO

Local Search Readiness

10/100
Poor
3 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

D42/100
Bot Access
19/25
Machine Read.
10/25
Schema Data
0/25
Citation
13/25

AI Bot Access

13/14 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:5%
Words:1,149
Token eff.:Optimal
Sections/1K:11.3
Depth:1/5

Structured Data

Microdata

Citation Readiness

Opening Summary28w
Descriptive Headingsavg 2.9w
Canonical URL
Open Graph2/3
Twitter Card0/3
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
71/100
11
Passed
3
Critical
1
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
5/15
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
9/15
Checks correct use of WAI-ARIA attributes (roles, states, properties) for assistive technologies.
3 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.
27/100
D
219 mg
CO₂e / view
1.7 MB
Page Weight
60%
Cleaner Than
New Visitor
250 mg
vs
Returning (cached)
125 mg
Annual (10K/mo)
26.2 kg
Emission Segments
Data Center
49 mg
Network
53 mg
Device
117 mg
Resource Breakdown
JavaScript
423.2 KB
Images
817.6 KB
CSS
465.6 KB
HTML
16.8 KB
Other
44.2 KB
Green Hosting Not Verified
True B.V
7 recommendations
  • •Carbon footprint recommendation preview...
Upgrade to view recommendations
F

Security Score

21%Critical
Interactive

HTTPS

No WAF

76d

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/2

Valid From

14.04.2026

Valid Until

13.07.2026

Subject Alternative Names (2)

naturalis.nlwww.naturalis.nl

SHA-256 Fingerprint

71:E3:BA:34:A3:1E:C8:2B:99:17:F2:B2:98:9A:4F:DD:AA:F1:DC:48...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations
Upgrade to view header details

HTTP Headers

Developer Console

cache-control
🔴 No Cache(no-cache)
content-length
1483
content-type
text/html
Good Warning Issue

Email Infrastructure

Google Workspace

Score

100

SPF
DKIM
DMARC

DMARC Policy

Reject (Strictest)

MX Records (5)

aspmx2.googlemail.com
aspmx3.googlemail.com
alt1.aspmx.l.google.com
alt2.aspmx.l.google.com

+1 more

Domain Information

naturalis.nl

Domain Age
28y 11m

Created

28.05.1997

Last Updated

17.03.2021

Registrar

Gandi

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.
C
69/100
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

Typography & Readability

platform + akkurat

WCAG Partial
55/100
Readability
/30
20/30

16px · LH 2.00

Hierarchy
/20
7/20
WCAG
/25
17/25

1:1 min contrast

Performance
/25
11/25

2 fonts · 9 req

Heading Font

platform

Sans

Body Font

akkurat

Sans16px

Contrast Ratio

1:1

40 issues

Reading Comfort

~35 CPL

Narrow lines
112px
h2
64px
h3
20px
h4
16px
p

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

⚠️ Wide line spacing (2.00). 1.4–1.6 is optimal for body text.

❌ Very complex text: Flesch score 22/100. Consider shorter sentences and simpler words.

⚠️ Partial contrast: 40 elements below WCAG AA threshold (min 1.0:1).

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

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

Buy on MyFontsFlesch 22

Color Palette

11 unique colors
4.55:1 AA Light
#ffffff
Background· 26.200000000000003%
#707967
Secondary· 7.6%
#585348
Primary· 7.9%
#434137
Secondary· 6.3%
#2b261e
Secondary· 5.9%
#835c4e
Secondary· 3%

Business & Marketing Stack

3 Tools Detected

Advanced

Behavior Analytics

2
Google Tag ManagerFree
Google AnalyticsFree

User behavior and product analytics

Advertising

1
Facebook PixelMid-Market

Ad platforms and retargeting pixels

2

Categories

3

Total Tools

0

Enterprise

1

Mid-Market

Assessment: Well-developed marketing technology stack

Sponsored

Scripts & Styles

15 Resources

12
Scripts
3
Styles
6
Async
0
Defer

Top Script Sources

local(5)googletagmanager.com(3)connect.facebook.net(2)google-analytics.com(1)avg.swis.nl(1)

Website Identity

naturalis.nl

28 years old
Location detected: 🇳🇱 Netherlandsvia tld
Gandi📧 Google Workspacenl

Sponsored

Last analyzed: 27 Apr 2026 at 21:10

Historical Analysis & Change Tracking