nenkin.go.jp

Readiness by lane

Green: nenkin.go.jp. Thin bar: Government Services peer median.

Priority fixes for nenkin.go.jp

Ordered by impact and by how common each practice is among peers.

1. Priority 1 · Harden

   HSTS kept for at least a year

   Observed: The homepage response did not include a Strict-Transport-Security header.

   Why it matters: HSTS tells browsers to use HTTPS for your host on every later visit, which removes the window where a first HTTP request can be intercepted.

   What to do: Send Strict-Transport-Security on HTTPS responses. Start with a short max-age (for example 300 seconds), confirm every subdomain works over HTTPS, then raise it in steps to 31536000. Add includeSubDomains only when all subdomains are HTTPS. HSTS preload is optional and hard to undo; hstspreload.org itself does not recommend it by default.

   On Amazon CloudFront: Attach a response headers policy with Strict-Transport-Security to each distribution.

   51% of Government Services peers do this. Limit: Read from the homepage response only; other pages or regions may send different headers.

   Guide: HTTPS and TLS Guide for Website Owners

2. Priority 2 · Accelerate

   Static files cached for 30 days or more

   Observed: A same-site stylesheet or script was cacheable for no max-age, short of the 30-day benchmark.

   What to do: Give versioned (fingerprinted) CSS, JavaScript, fonts and images Cache-Control: public, max-age=31536000, immutable, and change the file name whenever the content changes.

   30% of Government Services peers do this.

   Guide: Browser Caching Guide for Website Owners

3. Priority 3 · Enable

   XML sitemap discoverable

   Observed: No sitemap was listed in robots.txt or found at /sitemap.xml.

   What to do: Generate an XML sitemap of canonical URLs, reference it in robots.txt and submit it in Google Search Console.

   42% of Government Services peers do this.

   Guide: XML Sitemap Guide: Include Only URLs You Stand Behind

4. Priority 4 · Accelerate

   No render-blocking scripts in <head>

   Observed: The homepage <head> loaded 2 external scripts without async or defer.

   What to do: Add defer to scripts that need the DOM, async to independent ones such as analytics, or move them to the end of the body.

   39% of Government Services peers do this.

   Guide: Control Third-Party Scripts Before They Control Your Page

What nenkin.go.jp already does well

Practices fewer than half of Government Services peers use.

• DNSSEC signedDNSSEC delegation (DS record) present.19% of peers
• Nameservers spread across providersNameservers spread across more than one operator.25% of peers
• Reachable over IPv6IPv6 address published.27% of peers

What we saw

Homepage checked

https://www.nenkin.go.jp/

Homepage response

HTTP 200

TLS

TLSv1.3, HTTP/2

Certificate

Cybertrust Japan Co., Ltd., 365-day validity, expiring 2027-01-23

CDN or edge

Amazon CloudFront

DNS operators

3 self-run or other nameserver domains

DMARC policy

p=quarantine

Homepage HTML

45 KB, br

Images on homepage

79 (png 66, gif 13)

Limits: homepage only, one location, one moment. Header checks reflect the homepage response; other pages may differ.

Stack and providers

Seen in the homepage response, certificate and DNS. Provider pages compare how their customers configure the same checks.

All 31 checks

Select a gap for the method and fix. How each check works

Compare with other Government Services sites

• bmeb.gov.bd55
• city.nagoya.jp55
• funcionpublica.gov.co55
• ojk.go.id55
• sme.gov.ao55

Government Services readiness benchmark