codezine.jp

https://codezine.jp· First analyzed 02 May 2026· Updated 02 May 2026

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codezine.jp

Mobile

Sponsored

Hosting Provider

Colt Technology Services Co., Ltd.

IP Address

114.31.94.143

Site Location

🇯🇵 Japanvia tld

Server Location

🇯🇵 Chiyoda City, Japan

ASN

AS10021

Organization

Colt Technology Services Co., Ltd.

Server

Nginx

Nameservers

ns020-nl4cafo02sl896vi.n.d-53.jp.ns020-nl4cafo02sl896vi.n.d-53.net.ns020-nl4cafo02sl896vi.n.d-53.info.

Performance

Core Web Vitals

Weight

First Contentful Paint

3.0 s10%

Speed Index

3.8 s10%

Largest Contentful Paint

—25%

Total Blocking Time

0.0 ms30%

Cumulative Layout Shift

0.00025%

621 KB

136 requests

Image Optimization

Lazy Load

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Frontend

Styling

Bootstrap

Infrastructure

Hosting

Colt Technology Services Co., Ltd.

Technology Stack

14 Technologies Detected

Analytics

Google Analytics

Google Analytics 4

Facebook Pixel Microsoft Clarity

Libraries

CSS Frameworks

Other

Fonts

Tag Managers

Advertising

Web Servers

Customer Support

SEO Analysis

D57/100

Meta Tags7/15

Content9/12

Headings3/8

Technical14/25

E-E-A-T0/7

Images2/7

Links5/5

URL5/5

Social4/5

Freshness2/4

Mobile3/4

Indexability3/3

codezine.jpcodezine.jp

CodeZine（コードジン）

CodeZineは、株式会社翔泳社が運営するソフトウェア開発者向けのWebメディアです。「デベロッパーの成長と課題解決に貢献するメディア」をコンセプトに、現場で役立つ最新情報を日々お届けします。

Title Length15 chars

Recommended: 50-60 chars (~90px / 580px)

Description Length97 chars

Recommended: 120-160 chars

Issues (2)

• Missing H1 tag — every page should have exactly one H1
• Most images missing alt text (156/203) — critical for accessibility and SEO

11 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

30 URLs

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.

Sponsored

AI & LLM Readiness

F37/100

Bot Access

20/25

Machine Read.

7/25

Schema Data

0/25

Citation

10/25

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

Text ratio:4%

Words:723

Token eff.:Optimal

Structured Data

No Schema

Citation Readiness

Opening Summary

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 (12)

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.

71/100

Passed

Critical

Warnings

Images & Alt Text

15/20

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

Semantic Structure

13/20

Evaluates proper use of HTML5 semantic elements (header, nav, main, footer) and heading hierarchy.

Forms & Inputs

13/15

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.

4 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

77 mg

CO₂e / view

621.4 KB

Page Weight

80%

Cleaner Than

New Visitor

88 mg

Returning (cached)

44 mg

Annual (10K/mo)

9.2 kg

Emission Segments

Data Center

17 mg

Network

18 mg

Device

41 mg

Resource Breakdown

JavaScript

366.6 KB

Images

134.3 KB

CSS

1.8 KB

HTML

49.2 KB

Other

69.6 KB

Green Hosting Not Verified

Colt Technology Services Co., Ltd.

5 recommendations

•Carbon footprint recommendation preview...

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Security Score

0%Critical

Critical / Transactional

HTTPS

No WAF

68d

Certificate Details

Type

Organization Validated (OV)

Certificate Authority

Starfield Technologies, Inc.

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.2

HTTP Protocol

HTTP/1.1

Valid From

16.02.2026

Valid Until

10.07.2026

OCSP Stapling

Enabled

Subject Alternative Names (20)

www.shoeisha.co.jpshoeisha.co.jpshoeisha.jpproductzine.jpshikakuzine.jpminna-no-kurashi.jpenterprisezine.jpeczine.jp+12 more

SHA-256 Fingerprint

49:E6:EF:D2:1A:A2:00:A4:1C:75:CB:AF:AE:3D:F1:3A:14:A2:D7:EE...

Top Recommendations

Security recommendation preview

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Upgrade to view header details

HTTP Headers

Developer Console

cache-control

🟣 Private(private, must-revalidate)

connection

content-encoding

📦 Gzip(gzip)

content-type

text/html; charset=UTF-8

date

Sat, 02 May 2026 22:05:21 GMT

server

nginx

Good Warning Issue

Email Infrastructure

Google Workspace

Score

SPF

DKIM

DMARC

DMARC Policy

None (Monitor Only)

MX Records (5)

alt2.aspmx.l.google.com

alt1.aspmx.l.google.com

alt4.aspmx.l.google.com

alt3.aspmx.l.google.com

+1 more

Domain Information

codezine.jp

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

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.

78/100

Mobile Friendly110 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...

Upgrade to view recommendations

Typography & Readability

Helvetica Neue

WCAG Partial

60/100

Readability

/30

18/30

14px · LH 1.50

Hierarchy

/20

8/20

WCAG

/25

13/25

2.62:1 min contrast

Performance

/25

21/25

System fonts

Heading Font

Helvetica Neue

Sans

Body Font

Helvetica Neue

Sans14px

Contrast Ratio

2.62:1

3 issues

Reading Comfort

~47 CPL

Optimal (45–75)

24px

14px

⚠️ Small text: 14px may strain on mobile. Use ≥16px for WCAG compliance.

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

✅ Optimal line length: ~47 chars/line (ideal 45–75 CPL).

❌ Very complex text: Flesch score 0/100. Consider shorter sentences and simpler words.

⚠️ Partial contrast: 3 elements below WCAG AA threshold (min 2.6:1).

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

Flesch 0

Color Palette

9 unique colors

Light

#ffffff

Background· 60%

#2d6fa4

Primary· 5.9%

#bf8168

Secondary· 5.8%

#071d42

Accent· 4.9%

#9ebebf

Secondary· 4.6%

#e7e5e1

Border· 3.2%

#7e3c3e

Secondary· 2.6%

Business & Marketing Stack

5 Tools Detected

Enterprise

Behavior Analytics

Google Tag ManagerFree

Google AnalyticsFree

Microsoft ClarityFree

User behavior and product analytics

Advertising

Facebook PixelMid-Market

Ad platforms and retargeting pixels

Social Media

Facebook SDKFree

Social widgets and sharing tools

Sponsored

Scripts & Styles

26 Resources

Scripts

Styles

Async

Defer

Top Script Sources

connect.facebook.net(4)googletagmanager.com(4)cdn.cxense.com(2)securepubads.g.doubleclick.net(2)api-esp-ap.piano.io(1)

Website Identity

codezine.jp

Location detected: 🇯🇵 Japanvia tld

📧 Google Workspaceja

Social Profiles

Facebook X (Twitter)

Sponsored

Last analyzed: 02 May 2026 at 22:06

Historical Analysis & Change Tracking