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astron.nl

https://astron.nl· First analyzed 06 May 2026· Updated 06 May 2026
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astron.nl
Desktop screenshot of astron.nl
Mobile screenshot of astron.nl
Mobile

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Hosting Provider

National Aerospace Laboratory, Voorsterweg 31, 8316 PR Marknesse

IP Address

195.169.155.206

Site Location

🇳🇱 Netherlandsvia tld

Server Location

🇳🇱 Ubbergen, Netherlands

ASN

AS1103

Organization

National Aerospace Laboratory, Voorsterweg 31, 8316 PR Marknesse

Server

Apache

Nameservers

dns1.astron.nl.dns2.astron.nl.ns1.surfnet.nl.

Performance

100

Core Web Vitals

Weight

First Contentful Paint
465 ms10%
Speed Index
604 ms10%
Largest Contentful Paint
—25%
Total Blocking Time
0.0 ms30%
Cumulative Layout Shift
0.00025%
795 KB
72 requests

Image Optimization

Lazy LoadResponsiveShortPixel
0–49
50–89
90–100

Architecture Stack

Monolithic
⚙️ SSR
WordPress
cms
nov1.0Custom
by Rocketclowns
View Theme

Technology Stack

19 Technologies Detected

Plugins

6
Modern Events Calendar
Oxygen
Flying Press
Shortpixel Adaptive Images
Oxy Toolbox
Elementor

Libraries

3
jQueryv3.6.0
jQuery UI
AOS

Frameworks

2
Angular
Alpine.js

Other

2
GSAPv3.3.3AOS (Animate On Scroll)

Analytics

2
Google Analytics
Matomo

UI Components

1
Owl Carousel

CSS Frameworks

1
Tailwind CSS

Icon Libraries

1
Font Awesome

Web Servers

1
Apache

SEO Analysis

C69/100
20
3
2
Meta Tags14/15
Content3/12
Headings6/8
Technical23/25
E-E-A-T2/7
Images1/7
Links4/5
URL5/5
Social5/5
Freshness0/4
Mobile3/4
Indexability3/3
A
astron.nlastron.nl

ASTRON | Making discoveries in radio astronomy happen

ASTRON is the Netherlands Institute for Radio Astronomy, and is part of the Institutes organisation of NWO.

Title Length53 chars

Recommended: 50-60 chars (~323px / 580px)

Description Length107 chars

Recommended: 120-160 chars

Issues (2)

  • • Very thin content (8 words). Search engines need substantial content for ranking.
  • • Most images missing alt text (77/79) — critical for accessibility and SEO

5 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

721 URLs

robots.txt

67 rules

Local SEO

Local Search Readiness

16/100
Poor
5 12

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

F31/100
Bot Access
11/25
Machine Read.
7/25
Schema Data
6/25
Citation
7/25

AI Bot Access

4/14 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:1,094
Token eff.:Optimal

Structured Data

2 JSON-LD
Organization×1.1WebSiteSearchAction

Citation Readiness

Opening Summary
Descriptive Headings
Canonical URL
Open Graph3/3
Twitter Card3/3
Language Tag
Publish Date
Author Info
Lists
Tables
TL;DR / Summary
About Page Link
Recommendations (12)
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
65/100
8
Passed
5
Critical
0
Warnings
Images & Alt Text
20/20
Checks if images have descriptive alt text for screen readers and visually impaired users.
Semantic Structure
6/20
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
12/15
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
1/15
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.
50/100
B
98 mg
CO₂e / view
795.5 KB
Page Weight
80%
Cleaner Than
New Visitor
112 mg
vs
Returning (cached)
56 mg
Annual (10K/mo)
11.8 kg
Emission Segments
Data Center
22 mg
Network
24 mg
Device
53 mg
Resource Breakdown
JavaScript
268.6 KB
CSS
382.7 KB
Fonts
26.1 KB
HTML
101.7 KB
Other
16.3 KB
Green Hosting Not Verified
National Aerospace Laboratory, Voorsterweg 31, 8316 PR Marknesse
4 recommendations
  • •Carbon footprint recommendation preview...
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B

Security Score

75%Good
Critical / Transactional

HTTPS

No WAF

79d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Let's Encrypt

Key Algorithm

ECDSA (secp256r1) (256 bit)

Signature

ECDSA with SHA-384

TLS Version

TLSv1.3

HTTP Protocol

HTTP/1.1

Valid From

25.04.2026

Valid Until

24.07.2026

Subject Alternative Names (9)

astron.nlintranet.astron.nlintranet.jive.euintranet.jive.nljive.eujive.nlwww.astron.nlwww.jive.eu+1 more

SHA-256 Fingerprint

CC:89:39:BA:48:F2:5C:EF:25:97:2C:21:FB:79:6D:2E:A5:F3:F3:C3...

Top Recommendations

Security recommendation preview

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HTTP Headers

Developer Console

connection
Keep-Alive
content-encoding
📦 Gzip(gzip)
content-security-policy
frame-ancestors 'self'; upgrade-insecure-requests; object-sr...
content-type
text/html; charset=UTF-8
date
Wed, 06 May 2026 00:49:26 GMT
keep-alive
timeout=5, max=100
Good Warning Issue

Email Infrastructure

Microsoft 365

Score

95

SPF
DKIM
DMARC

DMARC Policy

Reject (Strictest)

MX Records (1)

astron-nl.mail.protection.outlook.com

Domain Information

astron.nl

Domain Age
29 years

Created

01.05.1997

Last Updated

04.01.2025

Registrar

SURF B.V.

DNSSEC
Not Enabled

Privacy & Compliance

Cookiebot

Cookie Consent Banner
Cookiebot
Privacy Policy
Terms of Service

GDPR Indicators

Cookie consent banner detected
CMP: Cookiebot
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
76/100
Mobile Friendly478 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
width=device-width, initial-scale=1.0
2 recommendations
  • •Mobile compatibility recommendation preview...
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Typography & Readability

SourceSansPro

WCAG Partial
72/100
Readability
/30
26/30

18px · LH 1.60

Hierarchy
/20
13/20

2.37x ratio

WCAG
/25
18/25

1:1 min contrast

Performance
/25
15/25

1 font · 2 req

Heading Font

SourceSansPro

Sans43px

Body Font

SourceSansPro

Sans18px

Contrast Ratio

1:1

11 issues

Reading Comfort

~37 CPL

Narrow lines
43px
h1
22px
h2
24px
h3
20px
h4
18px
p

✅ Excellent readability: 18px body text is ideal for all devices.

✅ Optimal line spacing: 1.60 ratio (ideal range 1.4–1.6).

❌ Very complex text: Flesch score 25/100. Consider shorter sentences and simpler words.

⚠️ Partial contrast: 11 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 2.4x larger than body text.

Buy on MyFontsFluid Type (rem)Flesch 25

Color Palette

13 unique colors
8.02:1 AAA Light
#ffffff
Background· 28.400000000000002%
#4f514e
Text· 7.2%
#03539b
Primary· 10.4%
#453937
Secondary· 6.9%
#d0d2c4
Secondary· 6.6%
#546369
Secondary· 5.3%
#9db2af
Secondary· 4.8%
#4f7d96
Secondary· 3.7%

Business & Marketing Stack

3 Tools Detected

Advanced

Marketing Automation

1
MailchimpSMB

Email marketing and automation platforms

Behavior Analytics

2
Matomo (Piwik)Mid-Market
Google AnalyticsFree

User behavior and product analytics

2

Categories

3

Total Tools

0

Enterprise

1

Mid-Market

Assessment: Well-developed marketing technology stack

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Scripts & Styles

30 Resources

20
Scripts
10
Styles
1
Async
9
Defer

Top Script Sources

static.mailplus.nl(10)(6)astron.nl(3)matomo.astron.nl(1)

Website Identity

ASTRON

ASTRON

Organization
info@astron.nl
www.astron.nl/
29 years old
Location detected: 🇳🇱 Netherlandsvia tld
SURF B.V.📧 Microsoft 365en-US

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Last analyzed: 06 May 2026 at 00:50

Historical Analysis & Change Tracking