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.
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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.
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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.
BURL Variantswww/non-www, trailing slash, HTTP→HTTPSREVIEW
www / non-www
Preferred variant: non-www
HTTP → HTTPS
HTTP version does not redirect to HTTPS
BTLS Certificate Expiry & Recommendations35 days until leaf cert expires — 3 issues to addressREVIEW
Certificate validity
Recommended actions
- Enable HSTS: Strict-Transport-Security: max-age=31536000; includeSubDomains
- 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 Records4 A records, 103 ms lookupPASS
| A | 185.199.109.153, 185.199.111.153, 185.199.110.153, 185.199.108.153 |
| AAAA | — |
| CNAME | — |
| NS | ns-38-b.gandi.net, ns-83-c.gandi.net, ns-83-a.gandi.net |
| MX | 10 spool.mail.gandi.net 50 fb.mail.gandi.net |
| TXT | google-site-verification=QssZbfwOh4lOaQS73YbJDtQl5PNuu5no8EzxYjgm0Go SPF v=spf1 include:_mailcust.gandi.net ?all |
| CAA | Lookup not available with standard resolver |
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.
A+Redirect ChainNo redirects — direct accessPASS
https://scikit-learn.org
124 ms · HTTP/1.1 FINAL
| # | URL | Status | Time | Protocol | Server |
|---|---|---|---|---|---|
| 1 | https://scikit-learn.org | 200 | 124 ms | HTTP/1.1 | GitHub.com |
A+Domain Intelligencescikit-learn.org — via Gandi SAS, 14 years, 8 months old, hosted on FastlyPASS
1221 days
October 19, 2029
35 days
Issued by Let's Encrypt
14 years, 8 months
Registered October 19, 2011
Not enabled
Protects against DNS spoofing
Fastly
ASN AS54113
185.199.111.153
Gandi SAS
Expiry timeline
Recommended actions
- Enable DNSSEC to protect visitors from DNS spoofing
- Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
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.
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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
The domain can be transferred without an unlock step. Enable registrar lock (clientTransferProhibited) in your registrar's control panel to protect against unauthorized or accidental transfers.
Without registrar lock, an attacker who phishes your registrar credentials can transfer the domain in minutes — total brand hijack.
Learn more ▾ ▴
Registrar lock (clientTransferProhibited, clientUpdateProhibited, clientDeleteProhibited) requires extra verification before any transfer/update/delete. Every major registrar offers it free. Combined with 2FA on your registrar account, it's the strongest defense against domain hijacking.
Source: ICANN / domain-security best practice