kakuyomu.jp

Readiness by lane

Green: kakuyomu.jp. Thin bar: Literary & Knowledge peer median.

Priority fixes for kakuyomu.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.

   69% of Literary & Knowledge 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 · Harden

   HSTS kept for at least a year

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

   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.

   28% of Literary & Knowledge peers do this.

   Guide: HTTPS and TLS Guide for Website Owners

3. Priority 3 · Accelerate

   Modern image formats in use

   Observed: The homepage had 36 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.

   On Next.js: The next/image component serves optimized formats automatically.

   31% of Literary & Knowledge peers do this.

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

4. Priority 4 · Enable

   Canonical URL declared

   Observed: The homepage did not declare a canonical URL.

   What to do: Add a self-referencing canonical link to every indexable page, using the final https:// URL.

   67% of Literary & Knowledge peers do this.

   Guide: Canonical Tags: A Decision Guide for Duplicate URLs

What kakuyomu.jp already does well

Practices fewer than half of Literary & Knowledge peers use.

• DMARC policy enforces quarantine or rejectDMARC policy p=quarantine.22% of peers
• Framing restrictedFraming controls present.37% of peers
• X-Content-Type-Options: nosniffnosniff header present.38% of peers

What we saw

Homepage checked

https://kakuyomu.jp/

Homepage response

HTTP 200

TLS

TLSv1.3, HTTP/2

Certificate

Amazon, 197-day validity, expiring 2026-12-20

CDN or edge

Amazon CloudFront

Platform or framework

Next.js

DNS operators

Amazon Route 53

DMARC policy

p=quarantine

Homepage HTML

310 KB, gzip

Images on homepage

36 (svg 7, png 5, jpg 2)

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 Literary & Knowledge sites

• dokumen.pub62
• duden.de62
• flowercomics.jp62
• kitabnagri.org62
• knoxt.space62

Literary & Knowledge readiness benchmark