Infrastructure
· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.CIPv6 ReadinessActionNo IPv6 supportREVIEW
IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.
No AAAA records — same impact as 'no IPv6 (AAAA) records'; IPv6-preferring clients pay extra latency falling back to IPv4.
Source: Google IPv6 stats
BCrawlabilityno robots.txt, no sitemapREVIEW
robots.txt is optional but recommended. It tells search engine crawlers which pages to index.
No robots.txt — crawlers fetch /robots.txt and get 404; not breaking but means default crawl behavior with no directives or sitemap reference.
Learn more ▾ ▴
A minimal robots.txt with `User-agent: * / Allow: / / Sitemap: https://example.com/sitemap.xml` covers the basics. Without it, crawlers behave fine but lose the sitemap signal and can't be selectively blocked from crawl-traps.
Source: robotstxt.org
A sitemap helps search engines discover and index your pages more efficiently.
No sitemap.xml — Google relies on crawl-graph discovery alone, slowing indexing of deep or fresh URLs.
Learn more ▾ ▴
A sitemap accelerates Google's discovery of new and updated content. Most CMSes auto-generate one; static-site frameworks need a build-step plugin. Reference it from robots.txt and submit in Search Console to confirm Google can fetch it.
Source: sitemaps.org / Google Search Central
No robots.txt found
This is fine for most sites — a missing robots.txt allows all crawling by default.
No sitemap found
Adding a sitemap helps search engines discover your pages.
BTLS Certificate Expiry & Recommendations45 days until leaf cert expires — 3 issues to addressREVIEW
Certificate validity
Recommended actions
- Add the preload directive and submit to hstspreload.org once max-age + includeSubDomains are in place
- Enable DNSSEC on your domain for DNS spoofing protection
- Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
A+DNS Records1 A records, 17 ms lookupPASS
| A | 198.252.206.1 |
| AAAA | — |
| CNAME | — |
| NS | damian.ns.cloudflare.com, sureena.ns.cloudflare.com |
| MX | 1 aspmx.l.google.com 5 alt2.aspmx.l.google.com 5 alt1.aspmx.l.google.com 10 alt3.aspmx.l.google.com 10 alt4.aspmx.l.google.com |
| TXT | onetrust-domain-verification=0d9d67f856334905a54256085a5768b3 anthropic-domain-verification-q70207=cKyy0llXkD10O4rDQpWz8tQ5K apple-domain-verification=O9jlnJXAQ7sNSZqC ZOOM_verify_AbkNwz5bBl0eurcDKyhhuk ibmid=4e7cbbb3-5f12-40b4-96c7-5b064347b822 v=MCPv1; k=ed25519; p=VhBofO8RaYvTvHT7q5tTty+HQeCU8R6h5Y8k/sj20So= openai-domain-verification=dv-GLNufzbWDzAq0fDXHD6jxeCK docker-verification=d65aee54-9091-4ceb-b792-61f5d5804050 SPF v=spf1 ip4:52.38.191.241 include:_spf1.stackoverflow.com ~all google-site-verification=2Bi6SYw5skkRexdtdLPL2gpxeIhLxnYVqITVP9Htl3w onetrust-domain-verification=e445562296a64c649ae3d520230b8c4c google-site-verification=ctogLnZNAdc_CXq8yOhODMLpmugGynjxKecKHDz4oL8 google-site-verification=o3EMam8yBGo1yEjyybIiZcOunGHOQKpo8JmOtp9n1BU adobe-idp-site-verification=25ba5203f3687c9cd6ee3223ee5de1528917828d1da3ebd3bd9a... google-site-verification=rdWtMbplKjbRHGr2dNONfwkqithlUvjr3u6i8QEz_mo docusign=4262531d-29f4-4a62-9f33-ae9f66f5247b MS=ms52592611 make-domain-verification=eec31159-f381-4f38-9d89-e59123dd023e atlassian-domain-verification=byLeZgl3MIcfOqwWuMhq8Fhr/1zem/jIaouJegvDZbBKUU5Oqh... cursor-domain-verification-sb0ayf=Pk6AyptQuTpzpcuSlfYGWloxv |
| CAA | Lookup not available with standard resolver |
Multiple A records provide failover if one server goes down.
Single A record means a single point of failure — if that IP goes down, your site is unreachable until DNS TTL expires.
Learn more ▾ ▴
Add multiple A records for round-robin failover, or use a managed DNS provider with health-checked failover (Route 53, Cloudflare, NS1). Short TTL (60-300s) lets clients recover faster on outages.
Source: SRE practice / DNS architecture
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Informational: CAA (Certification Authority Authorization) records weren't checked in this scan.
ARedirect Chain1 redirect(s), 372 ms totalPASS
https://stackoverflow.com
138 ms · HTTP/1.1
https://stackoverflow.com/questions
234 ms · HTTP/1.1 FINAL
| # | URL | Status | Time | Protocol | Server |
|---|---|---|---|---|---|
| 1 | https://stackoverflow.com | 302 | 138 ms | HTTP/1.1 | cloudflare |
| 2 | https://stackoverflow.com/questions | 200 | 234 ms | HTTP/1.1 | cloudflare |
See the visual redirect chain in the HTTP Probe tab →
If permanent, use 301 instead.
302 (Found) is for genuinely temporary redirects — if this redirect is permanent, switch to 301 to preserve SEO equity.
Learn more ▾ ▴
Search engines treat 302 as temporary, keeping the original URL indexed and not transferring full link equity to the destination. Use 301 (Moved Permanently) for permanent redirects (HTTP→HTTPS, www-vs-non-www, URL restructures).
Source: Google Search Central
A+URL Variantswww/non-www, trailing slash, HTTP→HTTPSPASS
www / non-www
Preferred variant: non-www
HTTP → HTTPS
Consistent
A+Domain Intelligencestackoverflow.com — via CSC Corporate Domains, Inc., 22 years, 7 months old, hosted on CloudflarePASS
169 days
February 2, 2027
45 days
Issued by Let's Encrypt
22 years, 7 months
Registered December 26, 2003
Not enabled
Protects against DNS spoofing
Cloudflare
ASN AS13335
198.252.206.1
CSC Corporate Domains, Inc.
Expiry timeline
Recommended actions
- Enable DNSSEC to protect visitors from DNS spoofing
DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.
Without DNSSEC, an attacker who can poison your DNS can hijack your domain — and SSL certs alone don't stop them.
Learn more ▾ ▴
DNSSEC adds cryptographic signatures to DNS records, preventing forged responses from poisoning resolver caches. Without it, an attacker who controls the network path can redirect your domain to a malicious server before any HTTPS handshake happens. Most modern registrars (Cloudflare, Google Domains, Route 53) enable it with one toggle.
Source: ICANN / RFC 4033