What technology does ndl.go.jp use?

ndl.go.jp is built with Vue.js, Nuxt, Google Analytics.

Is ndl.go.jp secure (HTTPS)?

Yes. ndl.go.jp uses TLS 1.3 with a certificate issued by Amazon, valid until Jan 10, 2027.

Hosting provider information for ndl.go.jp is not available yet.

What is ndl.go.jp's SEO score?

ndl.go.jp scored 75/100 for SEO in the latest analysis (fair).

What is ndl.go.jp's overall website score?

ndl.go.jp has an overall SiteGraph score of 93/100, combining SEO, performance, security, and accessibility.

Has ndl.go.jp's score changed over time?

ndl.go.jp's overall score has improved by 10 points (from 83 to 93) since Jul 25, 2026.

ndl.go.jp

国立国会図書館

Last scanned Aug 1, 2026, 7:00 AM · 13 views

Overall score

Excellent

Summary

国立国会図書館の公式ウェブサイトです。当館は、国内外の資料・情報を広く収集・保存して、知識・文化の基盤となり、国会の活動を補佐するとともに、行政・�… This website uses Nuxt behind CloudFront CDN. SEO is good (75/100) and accessibility is excellent (100/100). Security scores excellent (100/100) and performance excellent (100/100). Top issue: Meta description longer than 160 characters.

国立国会図書館の公式ウェブサイトです。当館は、国内外の資料・情報を広く収集・保存して、知識・文化の基盤となり、国会の活動を補佐するとともに、行政・司法及び国民に図書館サービスを提供しています。

Top issues to fix

6 issues found

Meta description longer than 160 characters
SEO
Trim the meta description to under 160 characters to avoid truncation in search results.
Missing canonical link
SEO
Add <link rel="canonical"> so search engines know which URL variant to index.
Multiple H1 headings found
SEO
Keep a single H1 per page and demote the others to H2/H3.
robots.txt not found
SEO
Publish /robots.txt with a Sitemap: directive to guide crawlers.
sitemap.xml not found
SEO
Publish an XML sitemap and reference it from robots.txt to speed up page discovery.
20 broken links on the page
SEO
Fix or remove broken links — they waste crawl budget and erode user trust.

SEO

5 issue(s) found

100

Performance

903 ms

100

Security

HTTPS & header checks

100

Accessibility

0 issue(s) found

Score history

+10 overall since Jul 25, 2026

Overall: 93
SEO: 75
Security: 100
Performance: 100
Accessibility: 100

Organization

Company details published in this site's own structured data.

X (Twitter)YouTube

Contact

Email, phone, and address published on this site's own pages.

Email: somoku1@ndl.go.jp

Meta tags

Title: 国立国会図書館
Description: 国立国会図書館の公式ウェブサイトです。当館は、国内外の資料・情報を広く収集・保存して、知識・文化の基盤となり、国会の活動を補佐するとともに、行政・司法及び国民に図書館サービスを提供しています。
Canonical
Language: ja
Charset: utf-8
Viewport: width=device-width, initial-scale=1, viewport-fit=cover
Robots meta
Manifest

Technologies

Detected frameworks, languages, and tools.

Vue.js Nuxt Google Analytics

Hosting & CDN

Hosting provider: —
CDN provider: CloudFront
IP address: —
ASN: —

DNS records

Type	Value
A	—
AAAA	—
MX	—
TXT	—
NS	—
CAA	—
CNAME	—
IPv6 support	No

TLS / SSL certificate

Version: TLS 1.3
Issuer: Amazon
Subject: www.ndl.go.jp
Valid from: Dec 12, 2025
Valid to: Jan 10, 2027
Days until expiry: 162
SAN domains: www.ndl.go.jp, hp.ndlsearch.ndl.go.jp

Security headers

Strict-Transport-SecurityEnabled
Content-Security-PolicyEnabled
X-Frame-OptionsEnabled
X-Content-Type-OptionsEnabled
Referrer-PolicyEnabled
Permissions-PolicyMissing

Compression: gzip · 0 cookie(s) observed

Content & assets

Headings

H1 2 · H2 4 · H3 0

Links

26 internal · 10 external · 20 broken

Images

9 total · 0 missing alt

Scripts / Styles

3 scripts · 2 stylesheets

JS / CSS size

6.9 KB · 60.9 KB

Page size

212 KB

Robots.txt & Sitemap

robots.txt: Not found
Disallow rules: 0
sitemap.xml: Not found
URLs in sitemap: 0

SEO issues

Meta description longer than 160 characters
Missing canonical link
Multiple H1 headings found
robots.txt not found
sitemap.xml not found

Scan details

Requested URL: https://ndl.go.jp
Final URL: https://www.ndl.go.jp:443/
HTTP status: 200
HTTP version: HTTP/2
Response time: 899 ms
HTML size: 212 KB
Redirect chain: https://ndl.go.jp → https://www.ndl.go.jp:443/

See something wrong on this report? Request a correction

Same technology stack

sleekplan.com

AI-Powered Customer Feedback Platform | Sleekplan

100

nuxtgoogle-analyticsvue

AWS· CloudFront

raben-group.com

Raben Group | Global Logistics, Transport & Supply Chain Solutions

nuxtgoogle-analyticsvue

blockpi.io

BlockPI Network | Global Distributed Web3 Infrastructure

nuxtgoogle-analyticsvue

Cloudflare· Cloudflare

api-bdc.io

BigDataCloud — Precise IP Geolocation & Reverse Geocoding APIs

nuxtgoogle-analyticsvue

AWS· Vercel

blockpi.network

BlockPI Network | Global Distributed Web3 Infrastructure

nuxtgoogle-analyticsvue

Cloudflare· Cloudflare

bitmain.com

BITMAIN

nuxtgoogle-analyticsvue

Cloudflare· Cloudflare

Frequently asked questions

What technology does ndl.go.jp use?: ndl.go.jp is built with Vue.js, Nuxt, Google Analytics.
Is ndl.go.jp secure (HTTPS)?: Yes. ndl.go.jp uses TLS 1.3 with a certificate issued by Amazon, valid until Jan 10, 2027.
Who hosts ndl.go.jp?: Hosting provider information for ndl.go.jp is not available yet.
What is ndl.go.jp's SEO score?: ndl.go.jp scored 75/100 for SEO in the latest analysis (fair).
What is ndl.go.jp's overall website score?: ndl.go.jp has an overall SiteGraph score of 93/100, combining SEO, performance, security, and accessibility.
Has ndl.go.jp's score changed over time?: ndl.go.jp's overall score has improved by 10 points (from 83 to 93) since Jul 25, 2026.

Top issues to fix

Score history

Organization

Contact

Meta tags

OpenGraph & Twitter Card

Technologies

Hosting & CDN

DNS records

TLS / SSL certificate

Security headers

Content & assets

Robots.txt & Sitemap

SEO issues

Accessibility issues

Scan details

Related websites

Frequently asked questions