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Free CNAME Record Lookup

Look up CNAME records for any domain. Follows the full resolution chain, detects the hosting service (AWS, Cloudflare, Vercel, Shopify, etc.), and shows associated A/AAAA records.

About this tool

A CNAME (Canonical Name) record is one of the most important DNS record types. It's essentially an alias — it points one domain name to another, allowing you to use subdomains like blog.example.com or shop.example.com while the actual hosting is handled by a third-party service.

This tool looks up the CNAME record for any hostname, follows the resolution chain (CNAME → CNAME → final IP), and identifies the underlying service. Enter a subdomain to see if it's pointing to Cloudflare, AWS, Shopify, Vercel, or any other platform.

CNAME records are crucial for email authentication too. When you set up email marketing with services like Sequenzy, you'll add CNAME records for DKIM authentication. Our DKIM checker verifies these records are set up correctly, and our MX record lookup checks your mail server configuration.

For a broader view of your DNS setup, also check our SPF checker and DMARC checker to make sure your domain's email authentication is properly configured.

Frequently Asked Questions

What is a CNAME record?

A CNAME (Canonical Name) record is a DNS record that maps one domain name to another. Instead of pointing directly to an IP address (like an A record), a CNAME says 'this domain is an alias for that domain.' For example, blog.example.com might have a CNAME pointing to example.wordpress.com. When someone visits blog.example.com, DNS follows the CNAME to find the actual IP address.

When should I use a CNAME vs an A record?

Use a CNAME when pointing a subdomain to an external service (blog platforms, CDNs, SaaS tools) — it automatically follows IP address changes. Use an A record when pointing to a specific IP address you control, or for your root domain (example.com), where CNAME records are not allowed by the DNS specification. A records are more direct (one lookup), while CNAMEs add a small latency overhead from the extra DNS hop.

Can I use a CNAME on my root domain (example.com)?

No. The DNS specification (RFC 1034) prohibits CNAME records on the zone apex (root domain). This is because CNAME records can't coexist with other record types, and root domains need SOA and NS records. Some DNS providers offer workarounds called 'ALIAS', 'ANAME', or 'CNAME flattening' that act like CNAMEs at the root level but are resolved by the DNS provider before serving the response.

Why do I need CNAME records for email?

CNAME records are commonly used for DKIM email authentication. When you set up an email sending service, they ask you to add CNAME records like em1234._domainkey.example.com pointing to their DKIM key servers. This proves to receiving mail servers that you authorized the sending service to send emails on behalf of your domain. Without these CNAMEs, your emails may fail DKIM authentication and land in spam.

What happens if a CNAME chain is too long?

Each CNAME hop requires an additional DNS query, adding latency. Most DNS resolvers limit CNAME chains to 8-10 hops and will return an error if the chain is longer. In practice, chains of 1-2 hops are normal and fine. If you see 3+ hops, the DNS setup might be overly complex. Very long chains can cause timeouts and make your website slower to resolve.

Can I have other records on a subdomain that has a CNAME?

No. The DNS specification states that if a CNAME record exists for a name, no other record types can exist for that same name. This means you can't have both a CNAME and an MX record, or a CNAME and a TXT record, on the same subdomain. This is one of the key limitations of CNAME records and the main reason they can't be used on root domains.

What is CNAME flattening?

CNAME flattening is a technique used by some DNS providers (Cloudflare, Route53, DNSimple) to work around the root domain CNAME restriction. Instead of returning a CNAME record, the DNS provider resolves the CNAME chain itself and returns the final A/AAAA records directly. To clients, it looks like a regular A record, but behind the scenes it follows a CNAME. This lets you point your root domain to services like Netlify or Heroku.

How long does it take for CNAME changes to propagate?

It depends on the TTL (Time To Live) of the old record. If the TTL was 3600 seconds (1 hour), DNS resolvers worldwide may serve the old value for up to an hour after you make the change. Most DNS providers let you lower the TTL before making changes to speed up propagation. After changing, full global propagation typically takes 1-48 hours, though most users see the change within the TTL period.

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