Website readiness profile · Snapshot 23 October 2026
zenn.dev
zenn.dev's public homepage, certificate and DNS checked against 31 practices and compared with 377 Forums & Communities sites.
- Readiness index
- 81/100
- Ahead of
- 95%
- Practices observed
- 23/30
- Popularity band
- Top 50K
Forums & Communities median 62
of measured Forums & Communities sites
1 of 31 could not be measured
Chrome UX Report top-sites list
Readiness by lane
Green: zenn.dev. Thin bar: Forums & Communities peer median.
Enable
92/100
Peers 74
Harden
91/100
Peers 54
Accelerate
56/100
Peers 60
Recover
0/100
Peers 7
Priority fixes for zenn.dev
Ordered by impact and by how common each practice is among peers.
Priority 1 · Accelerate
Modern image formats in use
Observed: The homepage had 12 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.
30% of Forums & Communities 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 · Accelerate
No render-blocking scripts in <head>
Observed: The homepage <head> loaded 1 external script without async or defer.
What to do: Add defer to scripts that need the DOM, async to independent ones such as analytics, or move them to the end of the body.
On Next.js: Use the next/script component with an appropriate loading strategy.
41% of Forums & Communities peers do this.
Guide: Control Third-Party Scripts Before They Control Your Page
Priority 3 · 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.
33% of Forums & Communities peers do this.
Priority 4 · 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.
37% of Forums & Communities peers do this.
What zenn.dev already does well
Practices fewer than half of Forums & Communities peers use.
- DNSSEC signedDNSSEC delegation (DS record) present.7.2% of peers
- CAA records limit who can issue certificatesCAA limits issuance to comodoca.com, digicert.com, letsencrypt.org and others.14% of peers
- Content Security Policy presentContent-Security-Policy present.17% of peers
What we saw
- Homepage checked
- https://zenn.dev/
- Homepage response
- HTTP 200
- TLS
- TLSv1.3, HTTP/2
- Certificate
- Google Trust Services, 90-day validity, expiring 2026-12-08
- CDN or edge
- Cloudflare, Google edge
- Platform or framework
- Next.js
- DNS operators
- Cloudflare
- HSTS
- max-age 730 days, includeSubDomains, preload
- DMARC policy
- p=quarantine
- Homepage HTML
- 223 KB, gzip
- Images on homepage
- 12 (png 11, 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
Not observed 7
Observed 23
- HTTP requests move to HTTPS
- HSTS kept for at least a year
- TLS 1.3 negotiated
- Certificate has more than 14 days left
- Certificate lifetime of 100 days or less
- CAA records limit who can issue certificates
- DNSSEC signed
- DMARC policy enforces quarantine or reject
- X-Content-Type-Options: nosniff
- Framing restricted
- Content Security Policy present
- HTTP/2 negotiated
- HTML compressed
- Offscreen images lazy-loaded
- robots.txt published
- XML sitemap discoverable
- Reachable over IPv6
- 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 1
- Static files cached for 30 days or more
Own zenn.dev?
Re-run the checks after a change, or verify the site in a free workspace to save reports with history, compare against similar sites and competitors, and track a private action plan. What owners get.
Live status for this site: Status Is Down: zenn.dev. This profile covers configuration only.