DNS Lookup Tool — Free Online Tool

The DNS Lookup Tool queries the public DNS records for a domain — A and AAAA records that point at server addresses, MX for mail routing, TXT for verification strings and SPF policies, NS for the authoritative nameservers, and CNAME aliases — and shows the answers with their TTL values.

The TTL is the field people ignore and then get caught by. It is how long a resolver is allowed to cache an answer, so after you change a record the old value keeps being served to some of the internet for up to that duration. This is exactly why a site "still points at the old server" for hours after a migration that you know you completed. Dropping the TTL to a few minutes a day before a planned change, then raising it again afterwards, is the standard way to avoid that window.

The records map onto real failure modes. A missing or wrong A record means the site does not resolve at all. Broken MX records mean mail silently bounces while the website carries on working perfectly, which is why email outages are often discovered late. TXT records carry SPF and DKIM policies, and a malformed SPF string is one of the most common reasons legitimate mail lands in spam. Checking what is actually published, rather than what you believe you configured, is usually the fastest way to find the discrepancy.

Queries run against public DNS resolvers; the domain you look up is not stored.

Our DNS Lookup Tool is completely free to use with no signup required. For this tool, processing runs in your browser — your files and data stay on your device and are not uploaded to our servers.

Whether you are a developer, designer, student, or business owner, this tool is designed to save you time and make your workflow more efficient. Bookmark this page to access it whenever you need it — it will always be free.