CNAME lookup
See what a hostname is an alias for. Look up its CNAME record and the chain it follows, live from a public resolver.
Related tools: DNS lookup · A record lookup · NS lookup · TXT record lookup · CAA record lookup · Reverse DNS lookup · DNS propagation checker · All free tools
What a name is an alias for
A CNAME record makes one hostname an alias for another: www.example.com is a CNAME for example.com, shop.example.com for a storefront platform, cdn.example.com for a CDN hostname. Resolvers follow the alias and answer with the target's records. This tool asks Cloudflare's 1.1.1.1 resolver for the CNAME record on a name and shows the target and the TTL, so you can confirm a hostname points where you configured it to.
That is where the alias points at this moment. When a vendor changes the hostname you were told to use, or someone edits the record by mistake, Upcheck spots the change in its 6-hourly DNS check and alerts your team.
Three steps, no signup
- 01
Enter a hostname
Usually a subdomain: www, shop, docs, cdn, mail. Apex domains rarely carry a CNAME.
- 02
We ask a public resolver
The CNAME query goes over DNS-over-HTTPS to Cloudflare's 1.1.1.1 from outside your network.
- 03
The target comes back
With the TTL, and with every intermediate name if the alias points at another alias.
Frequently asked questions
What is a CNAME record?
A canonical-name record. It says that a hostname has no records of its own and that resolvers should look up another name instead. It is how www.example.com can point at example.com, or how docs.example.com can point at a hosting platform's hostname, without you copying the platform's IP addresses into your zone and updating them every time they change.
Why can't I put a CNAME on my root domain?
Because a CNAME must be the only record at its name, and a root domain always has SOA and NS records. Publishing a CNAME at the apex violates the DNS standard and most providers refuse it. The usual workaround is a provider feature called ALIAS, ANAME, or CNAME flattening, which answers with the target's A records while keeping the apex valid. A lookup on such a name shows A records, not a CNAME.
The lookup shows no CNAME. Is that a problem?
Only if you expected one. NOERROR with no CNAME record means the name is not an alias; it has its own A, AAAA, or other records instead. Check those with the DNS lookup. If you added a CNAME recently and this resolver still returns nothing, the old answer is still cached within its TTL, or the record was added to a zone that isn't the one the domain's nameservers serve.
What is a CNAME chain and does it matter?
A chain is a CNAME whose target is itself a CNAME, and so on. Resolvers follow chains fine, but every hop is one more lookup before a visitor gets an address, and a broken link anywhere in the chain takes the name down. Keeping chains short is good practice; this tool shows every hop so you can see how long yours is.
Is this CNAME lookup free?
Yes. No account, no limit on lookups by hand; scripted use is rate limited. Upcheck's monitoring re-resolves every website you add every 6 hours and alerts your team when it stops resolving or its address records change.
One lookup confirms the alias. Monitoring confirms it keeps working.
Add your websites to Upcheck and get alerted by email, Slack, Discord, Teams, or webhook when a name stops resolving.