DNS checker tools let you query live DNS records to verify propagation, debug email issues, and inspect security policies. Enter any domain and select the record type to see real-time DNS data via Google's public resolver. Results show record values and TTL for each entry. Free, browser-based, no installation needed.
DNS Lookup queries real-time DNS records for any domain using Google DNS-over-HTTPS. Select from A, AAAA, MX, TXT, CNAME, NS, SOA, CAA, SRV, or PTR record types, enter a domain name, and see the live DNS response including record values, TTL, and record count. It also checks the three email authentication records that are stored as TXT entries at fixed names, DMARC at _dmarc, SPF on the domain itself, and DKIM at a selector under _domainkey, parsing each tag and flagging the mistakes that quietly break delivery such as a p=none DMARC policy, an SPF record over the ten DNS lookup limit, or a revoked DKIM key. DNS (Domain Name System) is the internet's address book: it translates human-readable domain names like example.com into IP addresses that computers use to route traffic. This tool is used by system administrators verifying DNS propagation after a migration, developers debugging email delivery (MX records), and security researchers checking TXT records for SPF, DKIM, and DMARC policies. For the reverse operation of looking up what information is associated with an IP address, see IP Address Lookup. To check whether a specific port is responding on a server, see Port Checker.
DNS resolution happens in multiple stages. When you type a domain name, your browser first checks its own cache, then the OS resolver cache, then queries your configured DNS resolver (usually your ISP or a public resolver like 8.8.8.8 or 1.1.1.1). If none have the record cached, the resolver performs a recursive query: it asks the root name servers for the TLD servers (.com, .net, etc.), then asks the TLD servers for the authoritative name servers of the specific domain, and finally asks the authoritative servers for the actual record. This entire process typically completes in under 100ms. DNS-over-HTTPS (DoH) encrypts DNS queries in HTTPS traffic, preventing ISPs and network observers from seeing which domains you query. It was standardized in RFC 8484 in 2018 and is now supported by all major browsers. Google and Cloudflare both operate free public DoH endpoints (dns.google and cloudflare-dns.com). TXT records have become a critical security mechanism: SPF (Sender Policy Framework) records specify which servers are allowed to send email for a domain, DKIM (DomainKeys Identified Mail) records provide public keys for verifying email signatures, and DMARC records tell receiving mail servers what to do when SPF or DKIM checks fail. Checking these records is the first step in diagnosing email deliverability problems.