j-cast.com

https://j-cast.com· First analyzed 25 Apr 2026· Updated 25 Apr 2026

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j-cast.com

Mobile

Sponsored

Hosting Provider

Mirai Communication Network Inc.

IP Address

210.172.200.251

Site Location

🇯🇵 中央区, Japanvia schema_nap

Server Location

🇯🇵 Gujō, Japan

ASN

AS7690

Organization

Mirai Communication Network Inc.

Nameservers

ns-71.awsdns-08.com.ns-900.awsdns-48.net.ns-1240.awsdns-27.org.ns-1656.awsdns-15.co.uk.

Performance

Core Web Vitals

Weight

First Contentful Paint

6.0 s10%

Speed Index

7.8 s10%

Largest Contentful Paint

—25%

Total Blocking Time

0.0 ms30%

Cumulative Layout Shift

0.00025%

2.2 MB

192 requests

Image Optimization

Lazy LoadWebPResponsive

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

Mirai Communication Network Inc.

Technology Stack

16 Technologies Detected

Analytics

Google Analytics

Google Analytics 4

Facebook Pixel Microsoft Clarity

Advertising

Google Ads Google AdSense Taboola

Icon Libraries

Font Awesome Material Icons

Libraries

UI Components

Other

CSS Frameworks

Fonts

Tag Managers

CDN

SEO Analysis

C65/100

Meta Tags5/15

Content9/12

Headings8/8

Technical17/25

E-E-A-T0/7

Images6/7

Links5/5

URL5/5

Social4/5

Freshness0/4

Mobile3/4

Indexability3/3

j-cast.comj-cast.com

J-CAST ニュース

ビジネスとメディアを独自の視点でウォッチ、日刊でニュースを提供。速報、特集、トピックス、新商品、読者コメントなど。

Title Length12 chars

Recommended: 50-60 chars (~74px / 580px)

Description Length58 chars

Recommended: 120-160 chars

Issues (1)

• Missing viewport meta tag — page may not be mobile-friendly (Google uses mobile-first indexing)

6 issues found

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Crawlability

Sitemap

Type: standard

162 URLs

robots.txt

16 rules

Sitemap reference found

Local SEO

Local Search Readiness

18/100

Poor

5 14 1

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

Sponsored

AI & LLM Readiness

D43/100

Bot Access

20/25

Machine Read.

5/25

Schema Data

7/25

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

nav

Text ratio:3%

Words:290

Token eff.:Too Short

Sections/1K:24.1

Depth:1/5

Structured Data

2 JSON-LD

Organization×1.1WebSiteSearchAction

sameAs entity links

Citation Readiness

Opening Summary223w

Descriptive Headingsavg 1.3w

Canonical URL

Open Graph3/3

Twitter Card1/3

Language Tag

Publish Date

Author Info

Lists

Tables

TL;DR / Summary

About Page Link

Recommendations (10)

AI readiness recommendation preview...

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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.

72/100

Passed

Critical

Warnings

Images & Alt Text

15/20

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

Semantic Structure

17/20

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

11/15

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.

3 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.

34/100

275 mg

CO₂e / view

2.2 MB

Page Weight

50%

Cleaner Than

New Visitor

314 mg

Returning (cached)

157 mg

Annual (10K/mo)

33.0 kg

Emission Segments

Data Center

61 mg

Network

66 mg

Device

148 mg

Resource Breakdown

JavaScript

658.6 KB

Images

1.3 MB

CSS

142.4 KB

Fonts

641 B

HTML

31.5 KB

Other

30.7 KB

Green Hosting Not Verified

Mirai Communication Network Inc.

7 recommendations

•Carbon footprint recommendation preview...

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Security Score

31%Critical

Interactive

HTTPS

No WAF

351d

Certificate Details

Type

Organization Validated (OV)

Certificate Authority

GlobalSign nv-sa

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

11.03.2026

Valid Until

12.04.2027

OCSP Stapling

Enabled

Subject Alternative Names (2)

*.j-cast.comj-cast.com

SHA-256 Fingerprint

2D:83:CF:33:BE:A4:25:AF:1E:0F:D9:92:A5:5C:CB:43:E4:6F:EB:D5...

Top Recommendations

Security recommendation preview

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HTTP Headers

Developer Console

content-encoding

📦 Gzip(gzip)

content-length

31948

content-type

text/html; charset=UTF-8

date

Sat, 25 Apr 2026 19:50:48 GMT

vary

Accept-Encoding

x-content-type-options

nosniff

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

MX Records (1)

mail.j-cast.com

Domain Information

j-cast.com

Domain Age

27y 1m

Created

16.03.1999

Expires

16.03.2027

Last Updated

14.03.2026

Registrar

Japan Registry Services Co., Ltd.

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.

56/100

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.

3 recommendations

•Mobile compatibility recommendation preview...

Upgrade to view recommendations

Typography & Readability

-apple-system

WCAG Partial

62/100

Readability

/30

14/30

12px · LH 1.40

Hierarchy

/20

12/20

1.33x ratio · ✓ H1→H6

WCAG

/25

17/25

1.13:1 min contrast

Performance

/25

19/25

System fonts

Heading Font

-apple-system

Sans16px

Body Font

-apple-system

Sans12px

Contrast Ratio

1.13:1

20 issues

Reading Comfort

Single Font Family

left aligned

16px

18px

16px

12px

Minor Second

Scale

❌ Critical: 12px body text is too small. Minimum 14px, recommend 16px+.

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

⚠️ Partial contrast: 20 elements below WCAG AA threshold (min 1.1:1).

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

⚠️ Weak hierarchy: Headlines should be ≥2x body size for clear visual structure.

✅ System fonts: Zero font loading delay — best possible LCP impact.

GGoogle Fonts

Color Palette

8 unique colors

11.49:1 AAA Light

#ffffff

Background· 37.800000000000004%

#3b3938

Text· 7.4%

#f1f0f5

Background· 28.099999999999994%

#89815e

Secondary· 8.3%

#2f75a0

Primary· 5.8%

#929a74

Secondary· 5.2%

#aab78e

Secondary· 4.3%

#d7c190

Secondary· 3.1%

Business & Marketing Stack

7 Tools Detected

Enterprise

Behavior Analytics

Google Tag ManagerFree

Google AnalyticsFree

Microsoft ClarityFree

User behavior and product analytics

Advertising

Google AdsEnterprise

Facebook PixelMid-Market

Ad platforms and retargeting pixels

Social Media

Twitter/X WidgetsFree

Facebook SDKFree

Social widgets and sharing tools

Sponsored

Scripts & Styles

24 Resources

Scripts

Styles

Async

Defer

Top Script Sources

cdn.cxense.com(3)connect.facebook.net(2)pagead2.googlesyndication.com(2)googletagmanager.com(2)scripts.clarity.ms(1)

Website Identity

J-CASTニュース

NewsMediaOrganization

www.j-cast.com/

27 years old

入船２丁目３−７築地エー・アイ・ユービル4階, 中央区

104-0042, 中央区, 東京都

Location detected: 🇯🇵 Japan, 中央区via schema_nap

Japan Registry Services Co., Ltd.ja

Social Profiles

Facebook X (Twitter)YouTube

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Last analyzed: 25 Apr 2026 at 19:51

Historical Analysis & Change Tracking