br31.jp

Readiness by lane

Green: br31.jp. Thin bar: E-Commerce & Marketplaces peer median.

Priority fixes for br31.jp

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

1. Priority 1 · Enable

   XML sitemap discoverable

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

   Why it matters: A sitemap helps search engines find new and updated pages, especially on large or frequently updated sites.

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

   87% of E-Commerce & Marketplaces peers do this. Limit: Only the standard location was requested, once, at the time of the check.

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

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.

   60% of E-Commerce & Marketplaces peers do this.

   Guide: Browser Caching Guide for Website Owners

3. Priority 3 · Accelerate

   Modern image formats in use

   Observed: The homepage had 80 images and none used WebP or AVIF.

   What to do: Serve WebP or AVIF with a JPEG or PNG fallback, either through an image CDN or by generating both formats at build time.

   47% of E-Commerce & Marketplaces peers do this.

   Guide: AVIF, WebP, JPEG, and PNG: Choose the Right Image Format

4. Priority 4 · Harden

   HSTS kept for at least a year

   Observed: Strict-Transport-Security was sent with a max-age of 183 days, below the one-year benchmark.

   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.

   32% of E-Commerce & Marketplaces peers do this.

   Guide: HTTPS and TLS Guide for Website Owners

What br31.jp already does well

Practices fewer than half of E-Commerce & Marketplaces peers use.

• No render-blocking scripts in <head>Head scripts load without blocking.44% of peers
• HTTP/3 advertisedHTTP/3 advertised.47% of peers

What we saw

Homepage checked

https://www.br31.jp/

Homepage response

HTTP 200

TLS

TLSv1.3, HTTP/2

Certificate

Amazon, 197-day validity, expiring 2027-03-01

CDN or edge

Amazon CloudFront

DNS operators

1 self-run or other nameserver domain

HSTS

max-age 183 days

DMARC policy

p=none

Homepage HTML

69 KB, gzip

Images on homepage

80 (svg 46, jpg 30, png 21)

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 E-Commerce & Marketplaces sites

• amazon.co.jp56
• ba-sh.com56
• clubhousegolf.co.uk56
• cotta.jp56
• wanuncios.com57

E-Commerce & Marketplaces readiness benchmark