Free tool
DNS Lookup
Look up the live DNS records for any domain, including A, AAAA, MX, NS, TXT, CNAME and SOA, straight from the authoritative answer.
What the records mean
A and AAAA point the domain at an IPv4 and IPv6 address. MX says which servers receive mail, and the priority number decides the order they are tried. NS lists the nameservers that hold the authoritative answers. CNAME makes one name an alias of another. TXT carries verification strings along with SPF and DMARC policies.
TTL is how many seconds a resolver is allowed to cache the answer. Lower it to a few minutes a day before a migration and the cutover is almost instant. Leave it at a day and some visitors will keep hitting the old server long after you have moved.
Changes take time to spread because every resolver between you and the visitor holds its own cache. If a record looks wrong here but right at your registrar, the answer is usually that the old value has not expired yet.