Stack playbook · Snapshot 23 October 2026
WordPress on Fastly: readiness playbook
What 462 measured sites on this stack get right, where they fall short, and the WordPress on Fastly-specific steps that close each gap.
- Sites measured
- 462
- Median readiness index
- 71/100
- Profiles on this stack
- 34
detected from homepage HTML and headers
all sites: 64
top-50K sites
Readiness by lane
Enable
93/100
All sites 77
Harden
61/100
All sites 55
Accelerate
70/100
All sites 63
Recover
7/100
All sites 11
The WordPress on Fastly playbook
Gaps ordered by impact, with the platform-specific step where one exists.
HSTS kept for at least a year
41% observed · all sites 31%
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.
On Fastly: Add the header in VCL or a header rule as described in Fastly's HSTS guide.
security.txt published
1.8% observed · all sites 5.5%
Publish /.well-known/security.txt with at least Contact and Expires fields, as RFC 9116 requires, and review it before it expires.
Modern image formats in use
38% observed · all sites 40%
Serve WebP or AVIF with a JPEG or PNG fallback, either through an image CDN or by generating both formats at build time.
On WordPress: WordPress has supported WebP uploads since 5.8 and AVIF since 6.5; image plugins or the host can convert existing images.
Guide: AVIF, WebP, JPEG, and PNG: Choose the Right Image Format
No render-blocking scripts in <head>
27% observed · all sites 44%
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 WordPress: Since WordPress 6.3, scripts can be registered with a defer or async loading strategy.
Guide: Control Third-Party Scripts Before They Control Your Page
CAA records limit who can issue certificates
11% observed · all sites 11%
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.
HTTP/3 advertised
24% observed · all sites 36%
Turn on HTTP/3 at your CDN. Browsers fall back to HTTP/2 automatically, so the risk is low.
DNSSEC signed
4.5% observed · all sites 8.1%
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
41% observed · all sites 31%
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
Where WordPress on Fastly sites lead
- Static files cached for 30 days or more93% observedall sites 50%
- Structured data present94% observedall sites 53%
- DMARC policy enforces quarantine or reject69% observedall sites 31%
- Social preview image set84% observedall sites 55%