Website readiness profile · Snapshot 23 October 2026
diamond.jp
diamond.jp's public homepage, certificate and DNS checked against 31 practices and compared with 3,856 News & Media sites.
- Readiness index
- 73/100
- Ahead of
- 69%
- Practices observed
- 18/29
- Popularity band
- Top 5K
News & Media median 68
of measured News & Media sites
2 of 31 could not be measured
Chrome UX Report top-sites list
Readiness by lane
Green: diamond.jp. Thin bar: News & Media peer median.
Enable
85/100
Peers 89
Harden
69/100
Peers 56
Accelerate
71/100
Peers 68
Recover
0/100
Peers 11
Priority fixes for diamond.jp
Ordered by impact and by how common each practice is among peers.
Priority 1 · Accelerate
Modern image formats in use
Observed: The homepage had 75 images and none used WebP or AVIF.
Why it matters: WebP and AVIF are typically much smaller than JPEG or PNG at similar quality, and images are often the heaviest part of a page.
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 Cloudflare: Cloudflare Polish can convert images to WebP.
44% of News & Media peers do this. Limit: Based on the homepage HTML delivered to an automated client; scripts that run later were not executed.
Guide: AVIF, WebP, JPEG, and PNG: Choose the Right Image Format
Priority 2 · Enable
Structured data present
Observed: The homepage had no JSON-LD structured data.
What to do: Add JSON-LD for your organization and main content types, then test it with Google's Rich Results Test.
76% of News & Media peers do this.
Priority 3 · Harden
Certificate lifetime of 100 days or less
Observed: The certificate from GlobalSign nv-sa had a 396-day validity period, longer than the 100-day maximum that applies from March 2027.
What to do: Move to automated issuance and renewal now, while you still have time to test it.
66% of News & Media peers do this.
Priority 4 · Accelerate
HTTP/3 advertised
Observed: The homepage did not advertise HTTP/3 through an Alt-Svc header.
What to do: Turn on HTTP/3 at your CDN. Browsers fall back to HTTP/2 automatically, so the risk is low.
On Cloudflare: Enable HTTP/3 (with QUIC) under Speed > Optimization > Protocol Optimization.
36% of News & Media peers do this.
What diamond.jp already does well
Practices fewer than half of News & Media peers use.
- HSTS kept for at least a yearHSTS with a 365-day max-age.35% of peers
- DMARC policy enforces quarantine or rejectDMARC policy p=reject.37% of peers
- X-Content-Type-Options: nosniffnosniff header present.42% of peers
What we saw
- Homepage checked
- https://diamond.jp/
- Homepage response
- HTTP 200
- TLS
- TLSv1.3, HTTP/2
- Certificate
- GlobalSign, 396-day validity, expiring 2027-02-20
- DNS operators
- Cloudflare
- HSTS
- max-age 365 days
- DMARC policy
- p=reject
- Homepage HTML
- 150 KB, gzip
- Images on homepage
- 75 (jpg 76, png 1, gif 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
Not observed 11
Observed 18
- HTTP requests move to HTTPS
- HSTS kept for at least a year
- TLS 1.3 negotiated
- Certificate has more than 14 days left
- DMARC policy enforces quarantine or reject
- X-Content-Type-Options: nosniff
- Framing restricted
- HTTP/2 negotiated
- HTML compressed
- Offscreen images lazy-loaded
- No render-blocking scripts in <head>
- XML sitemap discoverable
- Canonical URL declared
- Meta description written
- Mobile viewport configured
- Social preview image set
- Page language declared
- At most one redirect to the homepage
Not measured 2
- Static files cached for 30 days or more
- robots.txt published
Own diamond.jp?
Re-run the checks after a change, keep a private action plan in a free workspace, or report a mistake.
Live status for this site: Status Is Down: diamond.jp. This profile covers configuration only.