gakken.jp

https://gakken.jp· First analyzed 29 Apr 2026· Updated 29 Apr 2026

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gakken.jp

Mobile

Sponsored

Hosting Provider

BroadBand Tower, Inc.

IP Address

203.216.223.33

Site Location

🇯🇵 Japanvia tld

Server Location

🇯🇵 Minato, Japan

ASN

AS9607

Organization

BroadBand Tower, Inc.

Server

Nginx

Nameservers

ns-12.awsdns-01.com.ns-1232.awsdns-26.org.ns-1576.awsdns-05.co.uk.ns-887.awsdns-46.net.

Performance

Core Web Vitals

Weight

First Contentful Paint

853 ms10%

Speed Index

1.1 s10%

Largest Contentful Paint

—25%

Total Blocking Time

0.0 ms30%

Cumulative Layout Shift

0.00025%

35 KB

9 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

BroadBand Tower, Inc.

Technology Stack

1 Technologies Detected

Web Servers

Nginx

SEO Analysis

F30/100

Meta Tags5/15

Content2/12

Headings0/8

Technical7/21

E-E-A-T0/7

Images2/7

Links2/5

URL5/5

Social0/5

Freshness0/4

Mobile4/4

Indexability3/3

gakken.jpgakken.jp

お探しのページが見つかりません | 学研ホールディングス

株式会社学研ホールディングス

Title Length28 chars

Recommended: 50-60 chars (~171px / 580px)

Description Length14 chars

Recommended: 120-160 chars

Issues (3)

• Very thin content (24 words). Search engines need substantial content for ranking.
• Missing H1 tag — every page should have exactly one H1
• Missing viewport meta tag — page may not be mobile-friendly (Google uses mobile-first indexing)

13 issues found

Upgrade to view details

Local SEO

Local Search Readiness

6/100

Poor

2 13 2

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

Sponsored

AI & LLM Readiness

F29/100

Bot Access

20/25

Machine Read.

4/25

Schema Data

0/25

Citation

5/25

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:3%

Words:21

Token eff.:Too Short

Structured Data

No Schema

Citation Readiness

Opening Summary

Descriptive Headings

Canonical URL

Open Graph0/3

Twitter Card0/3

Language Tag

Publish Date

Author Info

Lists

Tables

TL;DR / Summary

About Page Link

Recommendations (11)

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.

69/100

Passed

Critical

Warnings

Images & Alt Text

20/20

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

Semantic Structure

14/20

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

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.

61/100

A+

4 mg

CO₂e / view

34.6 KB

Page Weight

95%

Cleaner Than

New Visitor

5 mg

Returning (cached)

2 mg

Annual (10K/mo)

516 g

Emission Segments

Data Center

1 mg

Network

1 mg

Device

2 mg

Resource Breakdown

Images

10.3 KB

CSS

22.1 KB

HTML

2.2 KB

Green Hosting Not Verified

BroadBand Tower, Inc.

3 recommendations

•Carbon footprint recommendation preview...

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Security Score

21%Critical

Interactive

HTTPS

No WAF

66d

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/1.1

Valid From

03.06.2025

Valid Until

05.07.2026

OCSP Stapling

Enabled

Subject Alternative Names (2)

*.gakken.jpgakken.jp

SHA-256 Fingerprint

63:4F:56:29:7F:54:49:D2:E6:E0:C7:42:B9:F4:CA:3A:6C:CA:D8:27...

Top Recommendations

Security recommendation preview

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Upgrade to view header details

HTTP Headers

Developer Console

connection

keep-alive

content-encoding

⚡ Brotli(br)

content-type

text/html; charset=UTF-8

date

Wed, 29 Apr 2026 20:42:56 GMT

etag

W/"657ff2b0-141d"

server

nginx

Good Warning Issue

Email Infrastructure

Amazon SES

Score

SPF

DKIM

DMARC

DMARC Policy

None (Monitor Only)

MX Records (1)

inbound-smtp.ap-northeast-1.amazonaws.com

Domain Information

gakken.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.

32/100

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...

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Typography & Readability

arial

WCAG Partial

64/100

Readability

/30

12/30

13px · LH 1.30

Hierarchy

/20

18/20

2x ratio · ✓ H1→H6

WCAG

/25

14/25

3.75:1 min contrast

Performance

/25

20/25

System fonts

Heading Font

arial

Sans26px

Body Font

arial

Sans13px

Contrast Ratio

3.75:1

8 issues

Reading Comfort

Single Font Family

left aligned

26px

13px

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

⚠️ Tight line spacing (1.30). Increase to 1.4–1.6 for better readability.

⚠️ Partial contrast: 8 elements below WCAG AA threshold (min 3.8:1).

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

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

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

Color Palette

7 unique colors

Light

#ffffff

Background· 93.2%

#039934

Primary· 2.3%

#eef3e6

Secondary· 2%

#8ecca5

Secondary· 0.7%

#5fa079

Secondary· 0.3%

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

2 Resources

Scripts

Styles

Async

Defer

Top Script Sources

Website Identity

gakken.jp

Location detected: 🇯🇵 Japanvia tld

📧 Amazon SESja

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Last analyzed: 29 Apr 2026 at 20:43

Historical Analysis & Change Tracking