NXDOMAIN: when a domain name cannot be found
NXDOMAIN is the answer the internet's address book gives when it has no entry for a name. Browsers show it as "this site can't be reached" or DNS_PROBE_FINISHED_NXDOMAIN.
What is happening
Before a browser can load your site, it asks the domain name system, DNS, for the address behind your domain name. NXDOMAIN means the reply was "there is no such name". The server may be running perfectly. Nobody can find it.
Why it happens to a site that used to work
- The domain registration ran out. This is the most common cause. Renewal emails went to an old address or the card on file expired.
- A DNS record was deleted or changed. Someone tidied up records, or a move to a new host removed the old ones.
- The name servers were changed. The domain now points to a DNS provider that has no records for it.
- Only a subdomain is affected. The main site works, but a name such as shop or www has no record of its own.
How to fix it as the owner
- Sign in at your registrar and check the expiry date and the status of the domain. Renew it if it lapsed.
- Check which name servers the domain uses, and that they belong to the DNS provider you really use.
- At that provider, check that the record for the affected name exists and points to your server.
- After a fix, allow some time. Other networks may remember the old answer for minutes or hours.
If only you see it
If the site loads for other people, your own computer or network has remembered a wrong answer. Restarting the browser, the device or the router usually clears it. A check from outside your network tells you which case you are in.