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 & Recommendations75 days until leaf cert expires — 3 issues to addressREVIEW
Certificate validity
Recommended actions
- Submit your domain to hstspreload.org to be added to the Chrome preload list
- 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
BCDN & DeliveryNetlifyREVIEW
A+DNS Records1 A records, 20 ms lookupPASS
| A | 75.2.60.5 |
| AAAA | — |
| CNAME | — |
| NS | ha1.markmonitor.zone, ha2.markmonitor.zone, ha3.markmonitor.zone, ha4.markmonitor.zone |
| MX | 10 aspmx.l.google.com 20 alt1.aspmx.l.google.com 30 alt2.aspmx.l.google.com 40 aspmx2.googlemail.com 50 aspmx3.googlemail.com |
| TXT | MS=ms78121488 a5ml0q2qredqkscjd0cnd3rs5o TAILSCALE-hgqvPubwp5HFczvxm0V3 ZOOM_verify_CZpP8WiXT3CuvCsqJO99fQ MS=297F6982EA6FC1794C4BC3FB5FF63A8E4CD4FAC4 ccisso=ccd758c0-2760-47f8-a10d-e5fc116fddae affinity-allowed-subdomains=a16z,a16z-crypto jamf-site-verification=r5S6YMFCZk83AroC1PcG8w 1password-site-verification=YNM3U5T3JZG5PEII74IIUKCOLQ elevenlabs=27i8sF6BnzYwPsZ5yq5TdjVJ000nf-OvqH4jBvfEnAQ openai-domain-verification=dv-CeeBac0VpbCCPpKaEHijwN7V gamma-domain-verification-gp4vsa=J4Meie8RekYZa4fxKQ5kuayqy cursor-domain-verification-7pnt8f=k0kHfixkiuNQWkL4COkqeKER8 anthropic-domain-verification-afe4hb=TrYvFm4pI5i7OwaiQnLdjFmZi perplexity-ai-domain-verification-66m0r7=3MZMPYJPZOdMXMDKTQAozQpXs google-site-verification=Cda284zEu8xh5veDdCm00SdfO_tJF-ebT809nkgB1zA censys-domain-verification=J1TG-Io7I9BckAxCWrurh86BYAQZGVEmTynNV9awatzH h1-domain-verification=vkosaeLv5aMSu6gt7GRxtajukLQ3hKGixbfbe9ZWR8VwKYf9 mgverify=0fe09ec683f6868bb8547d3edcd914093dd94e3957094a60fe4f5e496b2b9745 zapier-domain-verification-challenge=f9cf9944-aaa7-4e2b-aabf-d2a392c18e0c neat-pulse-domain-verification-4wMj96X=d2d2ebff-e37e-4bac-9efc-a5b0e583a0d4 hubspot-domain-verification=MWVlYzc1MzAtMzY4MC00MzNkLTk0NGQtOWU2Y2I3MTJiZDI2 SPF v=spf1 include:_spf.google.com include:_spf.salesforce.com include:spf.happyfox.... notion_verify_FvVFn84Y5fBnAntNFUjAg1p8Mox5n8sVJtGGVpmMeKV3PNqhbTdF1MsP5gWvM08GZq... stripe-verification=FC0027ACED84DA245559E90AA0BE435C9D507EE24C5CF17AFD11316B9808... wiz-domain-verification=5dc014a9a7637634bf88686260016ef95998390f9f1703e28716979f... atlassian-domain-verification=afgyuWvgwYP6dShfPqgKfpNFXkbap4546WDp6lt8DCGR1IykT5... |
| 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.
A+Redirect ChainNo redirects — direct accessPASS
https://a16z.com
138 ms · HTTP/1.1 FINAL
| # | URL | Status | Time | Protocol | Server |
|---|---|---|---|---|---|
| 1 | https://a16z.com | 200 | 138 ms | HTTP/1.1 | Netlify |
A+URL Variantswww/non-www, trailing slash, HTTP→HTTPSPASS
www / non-www
Preferred variant: non-www
HTTP → HTTPS
Consistent
A+Domain Intelligencea16z.com — via MarkMonitor Inc., 17 years, 5 months old, hosted on AWSPASS
579 days
January 13, 2028
75 days
Issued by Let's Encrypt
17 years, 5 months
Registered January 26, 2009
Not enabled
Protects against DNS spoofing
AWS
ASN AS16509
75.2.60.5
MarkMonitor Inc.
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.
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
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