DNS Lookup

Check DNS records from multiple resolvers (Google, Cloudflare, Quad9 and more) simultaneously.

Google Cloudflare Quad9 Verisign OpenDNS AdGuard Level3 Neustar CleanBrowsing

What is DNS?

DNS (Domain Name System) is the "phone book" of the internet. Every time you type a domain into your browser, DNS translates that name into an IP address — for example, example.com becomes 93.184.216.34. Without DNS, you would need to remember IP numbers for every website.

What does the Έλεγχος DNS from NerdTools do?

The Έλεγχος DNS simultaneously queries multiple DNS resolvers — Google, Cloudflare, Quad9, and others — and compares the results. If all of them return the same answer, your DNS is consistent worldwide. If there are differences, it means propagation is still in progress.

Main DNS record types

A record

Maps a domain or subdomain to an IPv4 address (e.g. 93.184.216.34). It is the most basic type — it defines which server your domain "points" to.

AAAA record

Same as A but for IPv6 addresses (e.g. 2606:2800:220:1:248:1893:25c8:1946). More and more networks support IPv6.

MX record

Mail Exchange — defines which servers are responsible for receiving email for your domain. If your email is not working, checking the MX record is the first troubleshooting step. Next to the MX records the email provider is auto-detected and shown with its logo (Google Workspace, Microsoft 365, Zoho, Proton, and more — plus spam-filters such as DNHost/SpamExperts).

NS record

Nameserver — indicates which DNS servers manage the records for your domain. It changes when you transfer a domain or switch DNS providers.

TXT record

Free-form text — used for SPF (anti-spam), DMARC, DKIM, domain verification in Google Search Console, and other services.

CNAME record

Canonical Name — an alias that "points" to another domain. Commonly used for www.example.com → example.com or for subdomains pointing to CDN/SaaS services.

When should you use the Έλεγχος DNS?

Right after changing nameservers or hosting provider — to confirm the change has propagated
When email is not working correctly — check the MX records
To verify that an SSL certificate will be issued correctly (A record)
When some users cannot reach your site — possible propagation lag
For security audits — check that SPF/DMARC TXT records exist

Frequently Asked Questions

Why do I see different answers from different resolvers?

After a DNS record change, the new value needs time to propagate to all resolvers worldwide (DNS propagation). This can take anywhere from a few minutes to 48 hours, depending on the record's TTL.

What does TTL mean in DNS?

TTL (Time To Live) is the time in seconds that a resolver can cache a record. A low TTL (e.g. 300 seconds) means faster propagation of changes but more queries to the DNS servers.

Can I check a subdomain?

Yes, simply enter the full subdomain (e.g. mail.example.com or www.example.com) in the search field.

What is the difference between Έλεγχος DNS and Διαγνωστικό DNS?

The Έλεγχος DNS displays the current DNS records from multiple resolvers. The Διαγνωστικό DNS performs a deep correctness check (45+ checks) for Parent/NS/SOA/MX/WWW with an OK/WARN/FAIL rating — ideal for auditing after a domain transfer or troubleshooting email.

📖 Read the full guide: How Long Does DNS Propagation Take? →