Stack playbook · Snapshot 23 October 2026
Astro: readiness playbook
What 173 measured sites on this platform or framework get right, where they fall short, and the Astro-specific steps that close each gap.
- Sites measured
- 173
- Median readiness index
- 74/100
- Profiles on this stack
- 99
detected from homepage HTML and headers
all sites: 64
top-50K sites
Readiness by lane
Enable
90/100
All sites 77
Harden
63/100
All sites 56
Accelerate
81/100
All sites 64
Recover
11/100
All sites 10
The Astro playbook
Gaps ordered by impact, with the platform-specific step where one exists.
HSTS kept for at least a year
49% observed · all sites 34%
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.
security.txt published
20% observed · all sites 7.1%
Publish /.well-known/security.txt with at least Contact and Expires fields, as RFC 9116 requires, and review it before it expires.
CAA records limit who can issue certificates
23% observed · all sites 13%
Publish CAA records naming every CA you actually use, including the CAs your CDN uses for managed certificates. Add an iodef contact if you want reports.
DMARC policy enforces quarantine or reject
54% observed · all sites 39%
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.
DNSSEC signed
13% observed · all sites 8%
Enable DNSSEC at your DNS provider, then add the DS record at your registrar. Plan provider moves carefully: a stale DS record can make the domain fail to resolve.
Guide: Website Uptime Readiness: Prepare Before Traffic Arrives
Content Security Policy present
35% observed · all sites 32%
Start with Content-Security-Policy-Report-Only to see what would break, tighten the policy over a few weeks, then enforce it.
Guide: Payment Security and PCI DSS: What Website Owners Need to Know
HTTP/3 advertised
49% observed · all sites 37%
Turn on HTTP/3 at your CDN. Browsers fall back to HTTP/2 automatically, so the risk is low.
Static files cached for 30 days or more
67% observed · all sites 51%
Give versioned (fingerprinted) CSS, JavaScript, fonts and images Cache-Control: public, max-age=31536000, immutable, and change the file name whenever the content changes.
Where Astro sites lead
- Modern image formats in use79% observedall sites 40%
- No render-blocking scripts in <head>80% observedall sites 48%
- Offscreen images lazy-loaded94% observedall sites 62%
- Referrer-Policy set46% observedall sites 24%