A record lookup: check IPv4 DNS records
TL;DR. The A record maps a hostname to a single IPv4 address. It is the most common DNS record on the public internet and the one most commonly broken.
How the A record works
An A record stores a 32-bit IPv4 address. Browsers, mail servers and CLI tools all start by resolving the A record of a hostname before opening a TCP connection. The shorter the TTL, the faster you can move traffic between IPs during a deployment or failover. When you change an A record, the old value can be cached by resolvers worldwide until its TTL expires, which is why a global A record check across multiple resolvers is the fastest way to confirm propagation.
Example A record
example.com. 3600 IN A 93.184.216.34Check a A record live
Run the multi-resolver probe → and confirm propagation of your A record across 12 global resolvers in real time.
Reference
Spec: RFC 1035.
A record FAQ
How do I check an A record? →
Enter a hostname into dnsprobe and we query the A record against 12 global resolvers in parallel. Identical answers across all resolvers mean the A record has fully propagated; a mismatch means it is still propagating.
How long does an A record take to propagate? →
A record propagation is bounded by the TTL of the previous record. With a 3600-second TTL, resolvers can serve the old IPv4 address for up to one hour after the change; lower the TTL before a planned change to speed this up.
Can a domain have multiple A records? →
Yes. Multiple A records on the same hostname enable simple round-robin DNS load balancing, where resolvers return all IPv4 addresses and clients pick one.