Introduction

ERR_NAME_NOT_RESOLVED means the browser could not turn the hostname into an IP address. The page fails before any web server response occurs, so this is a naming or DNS path issue rather than an application crash or HTTP problem.

Symptoms

  • Chrome reports ERR_NAME_NOT_RESOLVED
  • The site fails before any HTML or server headers appear
  • The domain or subdomain recently changed providers or records
  • Some devices fail while others still load the site
  • Email, API, or subdomain traffic may also be impacted if the same record set changed

Common Causes

  • The domain or subdomain record does not exist
  • Nameserver delegation points to the wrong provider
  • The domain expired or was suspended
  • Local resolver cache or enterprise DNS still holds stale or invalid answers
  • The requested hostname contains a typo or unsupported record target

Step-by-Step Fix

  1. Confirm the exact hostname users are trying to reach and rule out simple typos or wrong subdomain references.
  2. Check that the domain is active at the registrar and that its nameservers point to the DNS provider hosting the live zone.
  3. Verify the required A, AAAA, or CNAME record exists for the failing hostname in the authoritative zone.
  4. Query public resolvers and compare the answers with the authoritative nameservers to separate missing records from cache lag.
  5. If only one network fails, flush local DNS cache or test through another resolver to identify client-side caching issues.
  6. Restore missing records or correct the wrong target for the affected hostname.
  7. Review recent DNS migrations, CDN onboarding, or subdomain changes that may have removed or renamed the record.
  8. Re-test from the browser after authoritative DNS is correct and caches begin returning the expected answer.
  9. Document critical hostnames and record ownership so future changes do not accidentally remove active endpoints.