Short answer. ERR_NAME_NOT_RESOLVED means the browser couldn't translate the domain name into an IP address — DNS resolution failed. The usual culprits are a typo in the domain, a missing or wrong A/AAAA record, a broken ISP DNS server, or a stale cached answer. The first step is to check whether the domain resolves at all with nslookup example.com or dig example.com.
What ERR_NAME_NOT_RESOLVED means
Before connecting to a site, the browser asks DNS: "what IP does this domain have?" No answer means no connection. This happens before any HTTP, so the error has nothing to do with the site's server or SSL — only with the naming system.
ERR_NAME_NOT_RESOLVED is "domain not found." The server may be alive and well, but without working DNS you can't reach it.
Main causes
- Typo in the domain — the most common and most overlooked cause.
- No A/AAAA record — the domain points to no IP.
- ISP DNS server broken or temporarily unavailable.
- Stale cached answer in the browser, OS, or router.
- Expired domain — the registrar revoked delegation.
- Wrong NS servers after a hosting or DNS-provider change.
DNS diagnostics
Check whether DNS returns any IP and compare resolvers:
# Does the domain resolve?
nslookup example.com
dig example.com
# Ask a specific public DNS
dig @1.1.1.1 example.com
dig @8.8.8.8 example.com
# Just the resulting IP
dig +short example.comIf @1.1.1.1 answers but the ISP DNS doesn't, the problem is the ISP resolver. If no one answers, the problem is the domain records themselves.
User-side fix
- Check the domain spelling for typos.
- Flush the DNS cache:
ipconfig /flushdns(Windows) orsudo dscacheutil -flushcache(macOS). - Switch the DNS server to 1.1.1.1 or 8.8.8.8.
- Reboot the router — it caches DNS too.
- Open the site on mobile data to rule out your ISP.
Server-side fix
If the domain resolves for no one, fix the DNS records at your provider:
# Which NS servers are delegated to the domain
dig NS example.com
# Check A and AAAA directly at the authoritative server
dig A example.com @ns1.your-dns-provider.comMake sure A/AAAA records exist and point to the right IP, NS servers are correct, and the domain hasn't expired. After editing a record, mind the TTL — old answers may live for several more hours.
Causes and solutions
| Cause | Solution |
|---|---|
| Typo in the domain | Check and fix the address |
| No A/AAAA record | Add a record with the correct IP |
| ISP DNS broken | Switch to 1.1.1.1 / 8.8.8.8 |
| Stale cache | Flush the OS and router DNS cache |
| Expired domain / wrong NS | Renew the domain, fix NS |
How to prevent it from recurring
DNS problems are sneaky: a record disappears or the domain expires, and you find out from lost traffic. A DNS-type monitor checks resolution on schedule and alerts you when the domain stops resolving. A multi-region check shows whether the issue is global or limited to one DNS provider.
Check DNS records (A, AAAA, MX, NS, TXT) in one click, and the HTTP checker confirms availability after the DNS fix. If resolution won't recover, see DNS not resolving: what to do. For continuous control, read the monitoring guide.
FAQ
Is it my problem or the site's?
Run dig @1.1.1.1 example.com. If a public DNS resolves the domain but yours doesn't, the issue is local. If no one resolves it, the problem is in the domain records.
Why did the error appear after changing hosting?
Most likely the A records or NS servers weren't updated, or the old TTL hasn't expired. Check delegation with dig NS and wait for propagation.
How long to wait after changing a DNS record?
From a few minutes to 24–48 hours depending on TTL. Flush your local cache to see changes sooner.
Will switching DNS servers help?
If a broken ISP resolver is to blame, yes — 1.1.1.1 or 8.8.8.8 often fix it instantly. If the domain has no records, changing DNS won't help.