Free A record lookup
A Record Lookup
Free, no sign-up. We only fetch the public URL you enter.
Short answer
Enter a domain such as example.com above and the A record lookup queries DNS for its A records. The result lists each IPv4 address currently associated with the name and the TTL (time to live) in seconds, which tells you how long resolvers may cache that answer. Use it to confirm a hosting or CDN switch, to verify a DNS migration and to troubleshoot caching delays. If you also want to know when the site behind that address stops answering, monitordefend checks your homepage every five minutes and emails you.
- Free, no sign-up: every A record of a hostname with its TTL.
- Check the root domain and www separately – they are different names.
- A lower TTL before a change makes the new IPv4 address spread faster.
myshop.com. 300 IN A 203.0.113.10 myshop.com. 300 IN A 203.0.113.11 www.myshop.com. 3600 IN A 198.51.100.7
This free A record lookup finds the IPv4 address behind any domain or subdomain in seconds. Type a hostname, run the check and you see every A record that DNS currently publishes for it, together with its TTL. That is the fastest way to answer the question that sits underneath half of all “my website is broken” tickets: is this name actually pointing at the server I think it is pointing at?
How does the A record lookup work?
You enter a hostname – a bare domain like example.com or a subdomain like shop.example.com – and click the check button. The tool sends a DNS query of type A for exactly that name and prints what comes back: one line per record, with the IPv4 address and the TTL. Nothing is installed, nothing is stored about your domain, and you do not need an account.
Keep in mind that the lookup asks for one exact name. If www.example.com is configured as a CNAME alias, the answer reflects where that alias finally leads; if a name has no A record at all, you get an empty result rather than an error. An empty answer is useful information too: it often explains why a freshly created subdomain refuses to load.
What is an A record?
An A record – short for address record – maps a domain or subdomain to a 32-bit IPv4 address such as 203.0.113.10. It is the oldest and still the most common record type in DNS. Whenever a browser, an app or a mail server wants to talk to a name, it eventually needs an IP address, and for IPv4 networks the A record is where that address comes from.
- Browser Needs the address of myshop.com
- Resolver Checks its cache, else asks DNS
- Authoritative server Answers with the A record + TTL
- Web server Receives the HTTP request
Typically the address belongs to the server that runs your website, to a load balancer in front of several servers or to the edge network of a CDN. The record itself has no idea what lives behind the IP; it simply says “this name can be reached here”. Everything after that – which site the server shows, whether it answers at all – is decided by the web server, not by DNS.
Each A record also carries a TTL, the number of seconds that resolvers are allowed to keep the answer in their cache. This value quietly controls how fast your changes become visible, which is why the lookup always shows it next to the address.
When should you check an A record?
Most A record checks happen under time pressure, and they are worth doing before you start digging through server logs. A wrong address explains symptoms that otherwise look like a crashed application.
- The website does not load at all, or shows another site or a default hosting page.
- You moved to new hosting, a new CDN or a new load balancer and want to confirm the switch.
- You are verifying a DNS migration after changing nameservers to a different provider.
- Some visitors see the new version and others the old one – a typical propagation and caching question.
- A certificate request fails because the validation server reaches the wrong machine.
A record vs AAAA vs CNAME
Three record types decide where a hostname leads, and mixing them up is one of the most common DNS mistakes. A and AAAA both end in an IP address; a CNAME never does – it hands the question over to another name.
| Record | Points to | Typical use |
|---|---|---|
| A | An IPv4 address | Root domain or subdomain to a server, load balancer or CDN |
| AAAA | An IPv6 address | The same, for clients that connect over IPv6 |
| CNAME | Another hostname | Subdomain to a SaaS service, e.g. shop.example.com to a store platform |
Root domain, www and subdomains
example.com (often written as @ in DNS panels) and www.example.com are two separate hostnames. Each needs its own record, and forgetting one of them is the reason why a site “works with www but not without” or the other way round. Many setups give the root domain an A record and make www a CNAME pointing at the root; others give both names the same A records. Both approaches are fine as long as both names resolve.
Subdomains behave the same way: blog.example.com, api.example.com and mail.example.com are independent names, and none of them inherits the A record of the root domain. A wildcard record (*.example.com) is the only exception, and it only applies to names that have no record of their own. Look up each name you actually use instead of assuming.
Reading the result: IPs, TTL and surprises
Compare the returned address with the one your hosting provider or load balancer gives you. If it matches, DNS is not your problem and you can move on to the web server. If it does not match, the record is either outdated, set at the wrong DNS provider or still cached from before your change.
If you see an address you do not recognise, check whether your DNS is proxied through a CDN. With a proxy enabled, lookups return the provider’s edge IPs and your origin IP stays hidden – that is intended. An address from a private range such as 10.x.x.x, 172.16–31.x.x or 192.168.x.x, on the other hand, is a misconfiguration for any public site: those networks are only reachable inside an office or a data centre.
The TTL tells you how patient you need to be. A value of 300 means caches refresh within five minutes; 86400 means a resolver that fetched the old record just before your change may keep serving it for a full day.
Choosing a TTL for your A records
There is no single correct TTL. Short values between 300 and 900 seconds let changes roll out quickly and are a good fit for names you might need to move in a hurry. Long values of several hours reduce the number of queries, improve cache hit rates and make you slightly less dependent on your DNS provider being reachable at every moment.
A practical routine: run with a moderate TTL such as one hour in normal operation, lower it to 300 seconds a day or two before a planned move, make the change, confirm the new IPv4 address with a lookup and then raise the TTL again once everything is stable. Lowering the TTL only helps if you do it at least one old TTL period in advance, because resolvers still honour the value they cached earlier.
Multiple A records and round-robin DNS
A hostname may carry several A records. Resolvers then return all of them, often in rotating order, and clients pick one – a technique called round-robin DNS. It spreads load across servers and adds some redundancy for very little effort.
It is not the same as a load balancer with health checks, though. DNS does not know whether one of the addresses has died; it keeps handing it out until you remove the record. Clients that land on the dead IP may retry another one or may simply fail. If you rely on round-robin, remove broken servers from the record set quickly and keep the TTL short enough for that removal to matter.
Fixing a wrong A record
First find out where the authoritative zone is hosted: the nameservers of your domain decide which provider’s panel actually counts. Editing records at an old provider is a classic trap – the change saves without complaint and has no effect at all.
Then correct or replace the record, wait for the old TTL to run out and repeat the lookup. If the right address shows up but the site still misbehaves, the problem has moved up a layer: the web server may not have a virtual host for your name, a firewall may block the port, or the certificate on the new server may not cover the hostname yet.
A records and monitordefend
This lookup is a one-off check. monitordefend does not monitor DNS records themselves, but its uptime check requests your homepage every five minutes from Germany, so a wrong or deleted A record that takes the site offline is confirmed with a second attempt and reported by email.
Frequently asked questions
What is a DNS A record?
An A record maps a domain or hostname to an IPv4 address, so browsers, apps and other servers know which machine to connect to when they use that name.
Can an A record point to a hostname instead of an IP?
No. An A record must contain an IPv4 address. To point one hostname at another hostname, use a CNAME record, or an ALIAS/ANAME feature at the root domain if your DNS provider offers one.
Do I need separate A records for @ (root) and www?
Usually yes. example.com and www.example.com are different hostnames, so configure both – either with their own A records or by making www a CNAME of the root domain – so the site loads under either name.
Why does my A record show a CDN or proxy IP instead of my server IP?
If your DNS is proxied through a CDN or reverse proxy, lookups return the provider’s edge IPs. Visitors connect to the edge, which forwards requests to your origin; the origin IP stays hidden on purpose.
Can I add multiple A records for the same domain?
Yes. Several A records create round-robin DNS that spreads traffic across IPs. It is not health-checked load balancing, so remove addresses of servers that go down.
What TTL should I use for an A record?
A common choice is 3600 seconds in normal operation and 300 seconds around planned changes. Lower TTLs make changes spread faster; higher TTLs improve caching and reduce queries.
What happens if I point an A record to a private IP like 192.168.x.x?
Public visitors cannot reach it, because private ranges are only routable inside local networks. Internet-facing sites need a public IPv4 address in their A record.
How long does an A record change take to show up?
Up to the TTL of the old record. Resolvers that cached the previous answer keep using it until that time has passed; afterwards they fetch the new address.