Where letsencrypt.org points.
Follow a hostname through every alias to the addresses that answer, and see which platform it lands on.
Looking up…
What a CNAME does.
A CNAME makes one name an alias of another: www.example.com pointing to example.netlify.app means "ask that name instead". Resolvers follow the chain, sometimes through several aliases, until they reach addresses. When the platform changes its addresses, your alias follows without you doing anything.
No CNAME on the bare domain.
A name with a CNAME can hold no other records, and the bare domain (example.com) must hold its NS and SOA records. So the standards forbid a CNAME there. DNS hosts work around it with CNAME flattening or ALIAS records, which follow the chain themselves and answer with plain addresses.
Connecting a platform.
Most site builders and hosts ask for a CNAME on www and A records (or an ALIAS) on the bare domain. Use the exact values from the platform's own setup page, then look the name up here: once the chain ends at the platform, the platform can issue the certificate and serve the site.
When no CNAME shows.
A name behind a proxy, such as Cloudflare's, answers with the proxy's own addresses and hides where it points behind them. A flattened bare domain looks the same. The chain on this page is what the public internet sees.
Questions people ask.
What is a CNAME record?
A CNAME makes one name an alias of another, such as www.example.com pointing to a hosting platform's address. Resolvers follow the alias to the target's records.
Can I put a CNAME on my root domain?
No. The root domain must hold NS and SOA records, and a CNAME cannot share a name with other records. DNS hosts offer CNAME flattening or ALIAS records instead.
How do I check where a subdomain points?
Type the full hostname, such as www.example.com. The lookup follows every alias to the final addresses and names the platform it lands on.
Should I use a CNAME or an A record?
Use a CNAME when a platform gives you a hostname to point to, so its address changes follow automatically. Use an A record when you are given a fixed IP address, and on the root domain.
Hivex index
Short names, still free to register.
Starting something new? Hivex keeps a live index of short, brandable .si names nobody has claimed yet, each checked with the registry.
From code, or an AI assistant.
The same lookup is a free JSON API, with no key and open CORS, and a tool any AI assistant that speaks MCP can call.
curl "https://hivex.si/api/v1/tools/dns?name=letsencrypt.org&type=CNAME"More DNS tools
- DNS lookupAll records at once: A, AAAA, CNAME, MX, NS, TXT, CAA, SOA.
- MX lookupMail servers in priority order, the provider, SPF and DMARC at a glance.
- NS lookupName servers, the DNS host, SOA settings, and marketplace parking.
- TXT lookupSPF, DMARC, DKIM and verification tokens, joined and labelled.
- CAA lookupAllowed certificate authorities, wildcard rules and report addresses.
- DNS propagation checker13 public resolvers side by side, with how long each keeps its copy.
- Reverse DNSThe PTR hostname of an IPv4 or IPv6 address, checked both ways.
- DNS health checkEvery name server asked directly: one report, every check.
- DNSSEC checkerDS, keys and validation: where the chain of trust holds or breaks.
- Subdomain finderSubdomains from certificate logs, DNS and the archive.
- DNS historyPast IP addresses and hosts, from passive DNS.
- DNS setup helperThe records each platform asks for, checked live.
- Domain checkerIs a name free to register? Checked live on any extension.
Sources
- RFC 1034: Domain names, concepts and facilities, section 3.6.2
- RFC 2181: Clarifications to the DNS specification, section 10.1
- Cloudflare: CNAME flattening
By Hivex. Updated 10 October 2026. Lookups run live through Cloudflare's public resolver and are kept for at most five minutes.