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calculator.org

https://calculator.org· First analyzed 29 May 2026· Updated 29 May 2026
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calculator.org
Desktop screenshot of calculator.org
Mobile screenshot of calculator.org
Mobile

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Hosting Provider

Unknown Provider

Performance

100

Core Web Vitals

Weight

First Contentful Paint
534 ms10%
Speed Index
694 ms10%
Largest Contentful Paint
—25%
Total Blocking Time
0.0 ms30%
Cumulative Layout Shift
0.00025%
140 KB
22 requests
0–49
50–89
90–100

Architecture Stack

Monolithic
⚙️ SSR

Technology Stack

2 Technologies Detected

CSS Frameworks

1
Tailwind CSS

Analytics

1
Google Analytics

SEO Analysis

D56/100
16
8
1
Meta Tags8/15
Content9/12
Headings8/8
Technical13/25
E-E-A-T0/7
Images1/7
Links5/5
URL5/5
Social0/5
Freshness0/4
Mobile4/4
Indexability3/3
C
calculator.orgcalculator.org

calculator.org - calculator.org

The calculator home page

Title Length31 chars

Recommended: 50-60 chars (~179px / 580px)

Description Length24 chars

Recommended: 120-160 chars

Issues (1)

  • • Most images missing alt text (12/15) — critical for accessibility and SEO

9 issues found

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Crawlability

Sitemap
robots.txt

4 rules

Allows all crawlers

Local SEO

Local Search Readiness

3/100
Poor
1 14 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

D42/100
Bot Access
20/25
Machine Read.
14/25
Schema Data
0/25
Citation
8/25

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
navheader/footer
Text ratio:22%
Words:302
Token eff.:Optimal
Sections/1K:9.9
Depth:2/5

Structured Data

No Schema

Citation Readiness

Opening Summary113w
Descriptive Headingsavg 2.3w
Canonical URL
Open Graph0/3
Twitter Card0/3
Language Tag
Publish Date
Author Info
Lists
Tables
TL;DR / Summary
About Page Link
Recommendations (8)
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.
A
80/100
11
Passed
1
Critical
0
Warnings
Images & Alt Text
20/20
Checks if images have descriptive alt text for screen readers and visually impaired users.
Semantic Structure
20/20
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
9/15
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.
1 recommendation
  • •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.
60/100
A+
17 mg
CO₂e / view
140.4 KB
Page Weight
95%
Cleaner Than
New Visitor
20 mg
vs
Returning (cached)
10 mg
Annual (10K/mo)
2.1 kg
Emission Segments
Data Center
4 mg
Network
4 mg
Device
9 mg
Resource Breakdown
Images
125.3 KB
CSS
12.0 KB
HTML
3.1 KB
Green Hosting Not Verified
3 recommendations
  • •Carbon footprint recommendation preview...
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A

Security Score

88%Very Good
Static / Informational

HTTPS

No WAF

83d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

DigiCert Inc

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

21.02.2026

Valid Until

20.08.2026

OCSP Stapling

Enabled

Subject Alternative Names (1)

www.calculator.org

SHA-256 Fingerprint

52:F3:40:B4:57:FA:35:2E:42:F4:E9:6D:A4:81:DE:D0:2D:DB:45:3F...

Recommendations

Security recommendation preview

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HTTP Headers

Developer Console

cache-control
🟡 30s(public, must-revalidate, max-age=30)
content-encoding
⚡ Brotli(br)
content-security-policy
default-src https: 'unsafe-eval' 'unsafe-inline'; object-src...
content-type
text/html
date
Fri, 29 May 2026 22:10:31 GMT
etag
"32323327"
Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

0

SPF
DKIM
DMARC

Domain Information

calculator.org

Domain Age
26y 6m

Created

09.11.1999

Expires

09.11.2026

Last Updated

15.10.2025

Registrar

CSL Computer Service Langenbach GmbH d/b/a joker.com

DNSSEC
Not Enabled

Privacy & Compliance

Cookie Consent Banner
Privacy Policy
Terms of Service

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.
D
55/100
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
2 recommendations
  • •Mobile compatibility recommendation preview...
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Typography & Readability

tahoma + Verdana

WCAG AA
76/100
Readability
/30
23/30

16px · LH 1.40

Hierarchy
/20
17/20

2x ratio · ✓ H1→H6

WCAG
/25
22/25

5.16:1 min contrast

Performance
/25
14/25

2 fonts

Heading Font

tahoma

Sans32px

Body Font

Verdana

Sans16px

Contrast Ratio

5.16:1

WCAG AA (≥4.5:1)

Reading Comfort

~37 CPL

Narrow lines
32px
h1
29px
h2
24px
h3
16px
p

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

✅ Optimal line spacing: 1.40 ratio (ideal range 1.4–1.6).

❌ Very complex text: Flesch score 24/100. Consider shorter sentences and simpler words.

✅ WCAG AA contrast: All text meets 4.5:1 ratio (min 5.2:1).

✅ Perfect heading hierarchy: Sequential h1→h2→h3 with single H1 — ideal for SEO & accessibility.

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

Buy on MyFontsFlesch 24

Color Palette

8 unique colors
4.28:1 AA Large Light
#e3e3e3
Other· 38.5%
#626b69
Other· 8.6%
#3c3e6e
Primary· 8.6%
#c6ebe5
Secondary· 0.1%

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

1
Google AnalyticsFree

User behavior and product analytics

1

Categories

1

Total Tools

0

Enterprise

0

Mid-Market

Assessment: Growing marketing technology adoption

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Scripts & Styles

3 Resources

1
Scripts
2
Styles
1
Async
0
Defer

Top Script Sources

ssl.google-analytics.com(1)

Website Identity

calculator.org

26 years old
CSL Computer Service Langenbach GmbH d/b/a joker.comen

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Last analyzed: 29 May 2026 at 22:11

Historical Analysis & Change Tracking