How can you check which DNS records are currently active?

Start by identifying the domain’s authoritative nameservers through an NS lookup or the registrar account. Those servers hold the source zone for public DNS. Query them directly for the record type you need, such as A, AAAA, CNAME, MX, TXT, or CAA, to confirm what the DNS provider is publishing.
Then query several recursive resolvers to see what users may receive from cache. Command-line tools such as dig and nslookup show the answer, TTL, and responding server. Web-based DNS checkers are convenient for comparing regions, but they may simplify results or cache their own checks.
Use the exact hostname. Records for example.com, www.example.com, and _dmarc.example.com are independent. A CNAME lookup may lead to additional records at its target. For email authentication, request the selector-specific DKIM name instead of looking only at the root domain.
If the control panel and public result disagree, confirm that you edited the provider named by the active nameservers. A saved record in an old hosting panel has no effect after DNS was delegated elsewhere. Also check for duplicate or conflicting entries and allow any previous TTL to expire before evaluating a corrected value.