STATUS IS UPWEBSITE READINESS
Owner workspace
Explore SIU

Category benchmark · Snapshot 23 October 2026

SEO & Email Marketing: website readiness

31 configuration checks across 87 SEO & Email Marketing sites from the SID website catalog, with 41 individual profiles for sites in the Chrome UX Report top 50K.

Sites measured
87

all popularity bands

Median readiness index
62/100

all sites: 64

Profiles
41

top-50K sites

Weakest lane
Recover

lowest weighted score

Readiness by lane

Enable

77/100

All sites 77

Harden

55/100

All sites 56

Accelerate

66/100

All sites 64

Recover

3/100

All sites 10

Biggest gaps for SEO & Email Marketing sites

The checks with the most room to improve, weighted by impact.

  1. HSTS kept for at least a year

    36% 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.

    Guide: HTTPS and TLS Guide for Website Owners

  2. DMARC policy enforces quarantine or reject

    37% 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.

    Guide: A Practical Website Health Check for Owners

  3. security.txt published

    8.4% 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.

    Guide: A Practical Website Health Check for Owners

  4. Modern image formats in use

    41% 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.

    Guide: AVIF, WebP, JPEG, and PNG: Choose the Right Image Format

  5. CAA records limit who can issue certificates

    20% 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.

    Guide: HTTPS and TLS Guide for Website Owners

  6. Content Security Policy present

    27% 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

Where SEO & Email Marketing sites lead

  • Certificate lifetime of 100 days or less85% observedall sites 67%
  • No render-blocking scripts in <head>56% observedall sites 48%
  • Reachable over IPv655% observedall sites 48%
  • Static files cached for 30 days or more58% observedall sites 51%

Stack mix

CDN and edge

Platform or framework

DNS operator

Certificate authority

Readiness leaders

SEO & Email Marketing sites in the top 50K with the highest share of observed practices (at least 26 of 31 checks measured). This lists only what we observed on 23 October 2026; owners can request a correction.

  1. vidiq.com90/100
  2. ahrefs.com86/100
  3. semrush.com85/100
  4. resend.com82/100
  5. smallseotools.com81/100
  6. mailsuite.com79/100
  7. rekonise.com79/100
  8. klaviyo.com78/100
  9. mailchimp.com76/100
  10. seoclerk.com76/100

All 31 checks for SEO & Email Marketing

CheckLaneObservedAll sitesMeasured
HTTP requests move to HTTPSHarden87%91%82
HSTS kept for at least a yearHarden36%34%86
TLS 1.3 negotiatedHarden86%91%86
Certificate has more than 14 days leftHarden100%99%86
Certificate lifetime of 100 days or lessHarden85%67%86
CAA records limit who can issue certificatesHarden20%13%87
DNSSEC signedHarden4.6%8%87
security.txt publishedHarden8.4%7.1%83
DMARC policy enforces quarantine or rejectHarden37%39%87
X-Content-Type-Options: nosniffHarden41%48%86
Framing restrictedHarden48%51%86
Content Security Policy presentHarden27%32%86
Referrer-Policy setHarden20%24%86
HTTP/2 negotiatedAccelerate88%90%86
HTTP/3 advertisedAccelerate41%37%86
HTML compressedAccelerate93%93%86
Static files cached for 30 days or moreAccelerate58%51%74
Modern image formats in useAccelerate41%40%71
Offscreen images lazy-loadedAccelerate58%62%64
No render-blocking scripts in <head>Accelerate56%48%86
robots.txt publishedEnable79%76%87
XML sitemap discoverableEnable71%70%85
Reachable over IPv6Enable55%48%87
Canonical URL declaredEnable65%68%86
Meta description writtenEnable83%84%86
Mobile viewport configuredEnable95%94%86
Structured data presentEnable49%51%86
Social preview image setEnable49%57%86
Page language declaredEnable95%90%86
At most one redirect to the homepageEnable99%98%86
Nameservers spread across providersRecover3.5%10%86

SEO & Email Marketing profiles

Readiness index shown next to each site.