skymark.co.jp

Readiness by lane

Green: skymark.co.jp. Thin bar: Airlines peer median.

Priority fixes for skymark.co.jp

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

1. Priority 1 · Accelerate

   HTML compressed

   Observed: The homepage HTML (36 KB) was delivered without gzip, Brotli or zstd compression.

   Why it matters: Compression usually shrinks HTML several times over, so the first bytes of the page arrive sooner on slow connections.

   What to do: Enable Brotli or gzip for text responses (HTML, CSS, JavaScript, JSON, SVG) at the CDN or origin.

   89% of Airlines peers do this. Limit: Read from the homepage response only; other pages or regions may send different headers.

   Guide: How to Set a Website Performance Budget That Teams Can Keep

2. Priority 2 · Enable

   Mobile viewport configured

   Observed: The homepage had no viewport meta tag, so phones may render it zoomed out.

   What to do: Add <meta name="viewport" content="width=device-width, initial-scale=1"> and check the layout on small screens.

   97% of Airlines peers do this.

   Guide: Responsive Web Design Checklist for Real Devices

3. Priority 3 · Harden

   HSTS kept for at least a year

   Observed: Strict-Transport-Security was sent with a max-age of 1 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.

   60% of Airlines peers do this.

   Guide: HTTPS and TLS Guide for Website Owners

4. Priority 4 · Harden

   DMARC policy enforces quarantine or reject

   Observed: The DMARC policy for skymark.co.jp was p=none, which asks receivers to take no action on failing mail.

   What to do: Publish DMARC with p=none and a reporting address first, fix any legitimate senders that fail SPF or DKIM alignment, then move to quarantine and finally reject.

   63% of Airlines peers do this.

   Guide: A Practical Website Health Check for Owners

What skymark.co.jp already does well

Practices fewer than half of Airlines peers use.

• Nameservers spread across providersNameservers spread across more than one operator.19% of peers
• Social preview image setog:image present.44% of peers

What we saw

Homepage checked

https://www.skymark.co.jp/

Homepage response

HTTP 200, after 2 redirects

TLS

TLSv1.3, HTTP/2

Certificate

Cybertrust Japan Co., Ltd., 393-day validity, expiring 2026-12-29

CDN or edge

Akamai

DNS operators

2 self-run or other nameserver domains

HSTS

max-age 1 days, includeSubDomains, preload

DMARC policy

p=none

Homepage HTML

36 KB, uncompressed

Images on homepage

10 (png 9, jpg 1)

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 Airlines sites

• aerlingus.com40
• belavia.by43
• csair.com42
• pulkovoairport.ru38
• svo.aero48

Airlines readiness benchmark