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jacar.go.jp

https://jacar.go.jp· First analyzed 15 May 2026· Updated 15 May 2026
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jacar.go.jp
Desktop screenshot of jacar.go.jp
Mobile screenshot of jacar.go.jp
Mobile

Sponsored

Hosting Provider

Amazon Web Services (AWS)
aws.amazon.com

IP Address

3.164.68.78

Site Location

🇯🇵 Japanvia tld

Server Location

🇫🇮 Helsinki, Finland

ASN

AS16509

Organization

AWS CloudFront (GLOBAL)

Server

Apache

CDN

CloudFront

Nameservers

ns-1950.awsdns-51.co.uk.ns-670.awsdns-19.net.ns-1187.awsdns-20.org.ns-138.awsdns-17.com.

Performance

97

Core Web Vitals

Weight

First Contentful Paint
996 ms10%
Speed Index
1.3 s10%
Largest Contentful Paint
—25%
Total Blocking Time
0.0 ms30%
Cumulative Layout Shift
0.00025%
824 KB
51 requests
0–49
50–89
90–100

Architecture Stack

Monolithic
⚙️ SSR
Infrastructure
Platform
AWS CloudFront
CDN
CloudFront

Technology Stack

5 Technologies Detected

Analytics

2
Google Analytics
Google Analytics 4

CSS Frameworks

1
Tailwind CSS

Tag Managers

1
Google Tag Manager

Web Servers

1
Apache

SEO Analysis

D52/100
13
9
1
Meta Tags8/15
Content7/12
Headings8/8
Technical11/21
E-E-A-T0/7
Images1/7
Links5/5
URL5/5
Social3/5
Freshness0/4
Mobile1/4
Indexability3/3
J
jacar.go.jpjacar.go.jp

アジア歴史資料センター

アジア歴史資料センターは、近現代（1860年代から1945年前後）の日本とアジア近隣諸国との関係に関わる歴史資料（目録・画像）をインターネット上で提供する電子資料センター（データベース）であり、国立公文書館で運営されています。

Title Length11 chars

Recommended: 50-60 chars (~68px / 580px)

Description Length113 chars

Recommended: 120-160 chars

Issues (1)

  • • Most images missing alt text (11/20) — critical for accessibility and SEO

10 issues found

Upgrade to view details

Local SEO

Local Search Readiness

8/100
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

F39/100
Bot Access
20/25
Machine Read.
7/25
Schema Data
0/25
Citation
12/25

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:2%
Words:78
Token eff.:Too Short
Sections/1K:30
Depth:2/5

Structured Data

No Schema

Citation Readiness

Opening Summary49w
Descriptive Headingsavg 1.3w
Canonical URL
Open Graph2/3
Twitter Card1/3
Language Tag
Publish Date
Author Info
Lists
Tables
TL;DR / Summary
About Page Link
Recommendations (8)
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.
D
55/100
11
Passed
3
Critical
4
Warnings
Images & Alt Text
5/20
Checks if images have descriptive alt text for screen readers and visually impaired users.
Semantic Structure
18/20
Evaluates proper use of HTML5 semantic elements (header, nav, main, footer) and heading hierarchy.
Forms & Inputs
2/15
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...
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.
58/100
B
83 mg
CO₂e / view
824.1 KB
Page Weight
80%
Cleaner Than
New Visitor
95 mg
vs
Returning (cached)
48 mg
Annual (10K/mo)
10.0 kg
Emission Segments
Data Center
4 mg
Network
25 mg
Device
55 mg
Resource Breakdown
JavaScript
3.4 KB
Images
715.8 KB
CSS
85.1 KB
HTML
4.0 KB
Other
15.7 KB
Green Hosting Verified
Amazon Web Services (AWS)
Provider Match
4 recommendations
  • •Carbon footprint recommendation preview...
Upgrade to view recommendations
F

Security Score

21%Critical
Interactive

HTTPS

No WAF

137d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Japan Registry Services Co., Ltd.

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

12.09.2025

Valid Until

30.09.2026

OCSP Stapling

Enabled

Subject Alternative Names (2)

*.jacar.go.jpjacar.go.jp

SHA-256 Fingerprint

97:9E:50:7A:26:37:FA:C7:3A:67:7C:1F:1C:67:68:D7:D1:A9:34:8F...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations
Upgrade to view header details

HTTP Headers

Developer Console

age
237
content-encoding
⚡ Brotli(br)
content-type
text/html
date
Fri, 15 May 2026 15:51:21 GMT
etag
W/"312a-64ed63278a840"
last-modified
Tue, 07 Apr 2026 03:15:37 GMT
Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

30

SPF
DKIM
DMARC

Domain Information

jacar.go.jp

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.
C
66/100
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

Noto Sans JP

WCAG AA
70/100
Readability
/30
23/30

16px · LH --

Hierarchy
/20
16/20

2.4x ratio

WCAG
/25
15/25

4.64:1 min contrast

Performance
/25
16/25

1 font

Heading Font

Noto Sans JP

Sans38px

Body Font

Noto Sans JP

Sans16px

Contrast Ratio

4.64:1

WCAG AA (≥4.5:1)

Reading Comfort

~44 CPL

Narrow lines
38px
h1
24px
h2
18px
h3
16px
p

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

✅ WCAG AA contrast: All text meets 4.5:1 ratio (min 4.6:1).

⚠️ Minor heading issue: 0 level skip(s) detected. Maintain sequential order for screen readers.

✅ Strong hierarchy: Headlines are 2.4x larger than body text.

❌ Pure vw font sizes: Viewport units alone break browser zoom (WCAG 1.4.4 fail). Use clamp(rem, vw, rem).

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

Buy on MyFonts

Color Palette

8 unique colors
Light
#ffffff
Background· 40.4%
#d9e8ee
Primary· 10.7%
#004f90
Primary· 8.4%
#1d5a46
Accent· 4.2%
#76a0a3
Secondary· 4.2%
#cbead7
Secondary· 1.4%

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

15 Resources

10
Scripts
5
Styles
6
Async
0
Defer

Top Script Sources

googletagmanager.com(3)cse.google.com(2)local(2)google-analytics.com(1)google.com(1)

Website Identity

jacar.go.jp

Location detected: 🇯🇵 Japanvia tld
ja

Sponsored

Last analyzed: 15 May 2026 at 15:55

Historical Analysis & Change Tracking