StackOptic
Back to Search
boomportaal.nl favicon

boomportaal.nl

https://boomportaal.nl· First analyzed 12 May 2026· Updated 12 May 2026
Export
boomportaal.nl
Desktop screenshot of boomportaal.nl
Mobile screenshot of boomportaal.nl
Mobile

Sponsored

Hosting Provider

Cyso Hosting B.V.

IP Address

37.46.138.120

Site Location

🇳🇱 Netherlandsvia tld

Server Location

🇳🇱 Amsterdam, The Netherlands

ASN

AS25151

Organization

Cyso Hosting B.V.

Nameservers

ns0.transip.net.ns2.transip.eu.ns1.transip.nl.

Performance

79

Core Web Vitals

Weight

First Contentful Paint
2.4 s10%
Speed Index
3.2 s10%
Largest Contentful Paint
—25%
Total Blocking Time
0.0 ms30%
Cumulative Layout Shift
0.00025%
3.9 MB
123 requests

Image Optimization

Lazy LoadResponsiveVercel Image Optimization
0–49
50–89
90–100

Architecture Stack

Hybrid
🔀 Hybrid
Frontend
Framework
Next.js
Styling
Tailwind CSS
Infrastructure
Hosting
Cyso Hosting B.V.
CDN
Vercel Image

Technology Stack

7 Technologies Detected

Analytics

2
Google Analytics
Google Analytics 4

Meta Frameworks

1
Next.js

CSS Frameworks

1
Tailwind CSS

Icon Libraries

1
Font Awesome

Fonts

1
Google Fonts

Tag Managers

1
Google Tag Manager

SEO Analysis

D58/100
18
9
1
Meta Tags5/15
Content10/12
Headings0/8
Technical17/25
E-E-A-T0/7
Images6/7
Links5/5
URL5/5
Social3/5
Freshness0/4
Mobile4/4
Indexability3/3
B
boomportaal.nlboomportaal.nl

Boomportaal | Boomportaal

Boomportaal is het publicatieplatform van Boom uitgevers

Title Length25 chars

Recommended: 50-60 chars (~154px / 580px)

Description Length56 chars

Recommended: 120-160 chars

Issues (1)

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

10 issues found

Upgrade to view details

Crawlability

Sitemap

Type: index

7 URLs

7 sub-sitemaps

robots.txt

95 rules

Sitemap reference found

Local SEO

Local Search Readiness

12/100
Poor
4 11 2

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

Sponsored

AI & LLM Readiness

D49/100
Bot Access
20/25
Machine Read.
15/25
Schema Data
3/25
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
data-nosnippet

Machine Readability

llms.txtinvalid
llms-full.txt
Semantic HTML
Heading Hierarchy
navheader/footer
Text ratio:3%
Words:970
Token eff.:Optimal
Depth:2/5

Structured Data

1 JSON-LD
WebSiteSearchAction

Citation Readiness

Opening Summary41w
Descriptive Headings
Canonical URL
Open Graph2/3
Twitter Card2/3
Language Tag
Publish Date
Author Info
Lists
Tables
TL;DR / Summary
About Page Link
Recommendations (9)
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
12
Passed
4
Critical
3
Warnings
Images & Alt Text
18/20
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
10/15
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
7/15
Checks correct use of WAI-ARIA attributes (roles, states, properties) for assistive technologies.
4 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.
25/100
F
490 mg
CO₂e / view
3.9 MB
Page Weight
15%
Cleaner Than
New Visitor
560 mg
vs
Returning (cached)
280 mg
Annual (10K/mo)
58.8 kg
Emission Segments
Data Center
109 mg
Network
118 mg
Device
263 mg
Resource Breakdown
JavaScript
3.2 MB
Images
217.8 KB
CSS
422.5 KB
HTML
32.3 KB
Other
8.6 KB
Green Hosting Not Verified
Cyso Hosting B.V.
6 recommendations
  • •Carbon footprint recommendation preview...
Upgrade to view recommendations
D

Security Score

46%Poor
Interactive

HTTPS

No WAF

198d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

PerfectSSL

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/1.1

Valid From

11.11.2025

Valid Until

26.11.2026

OCSP Stapling

Enabled

Subject Alternative Names (12)

www.boomportaal.nltijdschriften.vakgebieden.rijks.boomportaal.nltijdschriften.rechtsgebieden.rijks.boomportaal.nltijdschriften.rechtsgebieden.boomportaal.nlboeken.vakgebieden.rijks.boomportaal.nlcms.boeken.vakgebieden.boomportaal.nlboeken.rechtsgebieden.rijks.boomportaal.nlboeken.vakgebieden.boomportaal.nl+4 more

SHA-256 Fingerprint

F6:C0:33:0C:F9:90:D1:2D:88:C3:10:42:47:88:7A:59:CF:7E:DE:6F...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations
Upgrade to view header details

HTTP Headers

Developer Console

access-control-allow-credentials
true
access-control-allow-headers
*
access-control-allow-methods
GET, POST, PUT, PATCH, DELETE, OPTIONS
access-control-allow-origin
*
cache-control
🔴 No Cache(private, no-cache, no-store, max-age=0, must-revalidate)
content-encoding
📦 Gzip(gzip)
Good Warning Issue

Email Infrastructure

Microsoft 365

Score

100

SPF
DKIM
DMARC

DMARC Policy

Reject (Strictest)

MX Records (1)

boomportaal-nl.mail.protection.outlook.com

Domain Information

boomportaal.nl

Domain Age
10y 8m

Created

26.08.2015

Last Updated

02.12.2021

Registrar

team.blue nl B.V.

DNSSEC
Not Enabled

Privacy & Compliance

Cookie Consent Banner
Privacy Policy
Terms of Service

GDPR Indicators

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
67/100
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
2 recommendations
  • •Mobile compatibility recommendation preview...
Upgrade to view recommendations

Typography & Readability

Source Sans Pro

WCAG Partial
52/100
Readability
/30
12/30

13px · LH 1.50

Hierarchy
/20
10/20
WCAG
/25
14/25

2.54:1 min contrast

Performance
/25
16/25

1 font · 5 req

Heading Font

Source Sans Pro

Body Font

Source Sans Pro

Sans13px

Contrast Ratio

2.54:1

15 issues

Reading Comfort

~36 CPL

Narrow lines
13px
p

❌ Critical: 13px body text is too small. Minimum 14px, recommend 16px+.

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

❌ Very complex text: Flesch score 2/100. Consider shorter sentences and simpler words.

⚠️ Partial contrast: 15 elements below WCAG AA threshold (min 2.5:1).

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

✅ Smart font loading: font-display: swap prevents invisible text during load (FOIT).

Buy on MyFontsFlesch 2

Color Palette

7 unique colors
4:1 AA Large Light
#7f7f7f
Other· 62.300000000000004%
#ffffff
Text· 11.5%
#050b1b
Primary· 9.4%
#5d3d39
Secondary· 5%
#323a52
Secondary· 4.9%

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

27 Resources

20
Scripts
7
Styles
5
Async
9
Defer

Top Script Sources

local(15)googletagmanager.com(4)cdn.cookiehub.eu(1)

Website Identity

boomportaal.nl

klantenservice@boom.nl
088-0301000
10 years old
Location detected: 🇳🇱 Netherlandsvia tld
team.blue nl B.V.📧 Microsoft 365nl

Sponsored

Last analyzed: 12 May 2026 at 20:13

Historical Analysis & Change Tracking