cecile.co.jp

Readiness by lane

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

Priority fixes for cecile.co.jp

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

1. Priority 1 · Accelerate

   HTTP/2 negotiated

   Observed: The TLS handshake selected http/1.1 instead of HTTP/2.

   Why it matters: HTTP/2 sends many files over one connection, which speeds up pages with lots of images, styles and scripts.

   What to do: Enable HTTP/2 on your CDN or server. Most CDNs do this by default.

   94% of E-Commerce & Marketplaces peers do this. Limit: Certificate and protocol were observed from one vantage point; CDNs can present different certificates by region.

   Guide: CDN 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 1310 seconds, 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 179 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: 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.

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

   Guide: HTTPS and TLS Guide for Website Owners

What cecile.co.jp already does well

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

• DNSSEC signedDNSSEC delegation (DS record) present.7.7% of peers
• Nameservers spread across providersNameservers spread across more than one operator.11% of peers
• DMARC policy enforces quarantine or rejectDMARC policy p=quarantine.39% of peers

What we saw

Homepage checked

https://www.cecile.co.jp/

Homepage response

HTTP 200

TLS

TLSv1.3, http/1.1

Certificate

DigiCert, 366-day validity, expiring 2026-12-19

DNS operators

3 self-run or other nameserver domains

DMARC policy

p=quarantine

Homepage HTML

202 KB, gzip

Images on homepage

179 (jpg 155, png 20, svg 4)

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

• bim.com.tr55
• buyma.com55
• bw-online-shop.com55
• comicomi-studio.com55
• cosme.com55

E-Commerce & Marketplaces readiness benchmark