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Definition
An A record is a DNS record that points a domain name or subdomain to an IPv4 address. It tells browsers and other internet systems where to find the server that should respond when someone visits that hostname.
A records are most often used to connect a website domain, such as example.com, to a web server. They are different from MX records for email, CNAME records for aliases and AAAA records for IPv6 addresses.
Key Takeaways About A Records
- An A record maps a hostname, such as your domain or a subdomain, to an IPv4 address.
- A records are commonly used for websites, staging environments, apps, server endpoints and some verification setups.
- Changing an A record can affect website availability, SSL/TLS behaviour, integrations and search visibility if the change is poorly planned.
Plain English Explanation
How an A Record Connects a Domain to a Website
Simple A Record Example
A DNS zone may include an A record for the root domain and a separate record or alias for the www version. The exact setup depends on the hosting platform, DNS provider and website configuration.
Type: A
Name: @
Value: 203.0.113.10
TTL: 300
Type: A
Name: app
Value: 203.0.113.25
TTL: 300203.0.113.0/24 is a documentation IP range used here as an example, not a live server address.
How It Works
What Happens When a Browser Uses an A Record
The full DNS process can involve several systems, but the basic flow is simple. The browser asks where a domain points, DNS responds with the relevant record, then the browser connects to the server.
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The visitor requests a domain
A person enters a domain such as example.com into a browser. The browser needs an IP address before it can contact the website server.
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DNS returns the A record
The DNS resolver checks the domain’s records and receives the IPv4 address stored in the A record for that hostname.
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The browser connects to the server
The browser sends the website request to that IP address. The server then needs to be configured to respond for the requested domain.
Common Uses
When Is an A Record Used?
A Record vs CNAME Record vs AAAA Record
A records are often confused with other DNS record types. The right choice depends on whether you need to point to an IPv4 address, an IPv6 address or another hostname.
| Record Type | What It Points To | Typical Use |
|---|---|---|
| A record | An IPv4 address, such as 203.0.113.10. | Connecting a domain or subdomain directly to a website or application server. |
| CNAME record | Another hostname, such as hosting.example.net. | Creating an alias when the destination may be managed by another service. |
| AAAA record | An IPv6 address. | Connecting a hostname to infrastructure that supports IPv6. |
An A Record Does Not Control Everything
Business Impact
Why A Records Matter for Websites, SEO and Business Continuity
Common A Record Mistakes
A record changes can look simple, but small mistakes can interrupt a live website. These are common issues we look for when reviewing DNS setups.
Changing the root domain but forgetting www
Do this instead
Check both the apex domain and the www hostname. They may use separate records, or one may redirect to the other through the website server.
Pointing DNS to a new server before it is ready
Do this instead
Prepare and test the new hosting environment first. Confirm SSL/TLS, redirects, forms and key pages before changing live DNS records.
Assuming DNS propagation is instant everywhere
Do this instead
Plan for caching and propagation delays. Lowering TTL before a planned migration can help, but it does not remove every delay.
Troubleshooting A Record Problems
If a website stops loading after an A record change, the cause may be DNS, hosting, SSL/TLS or server configuration. It is important to diagnose the layer that is actually failing.
The website is showing the old version after a DNS change
Likely cause
DNS caching or propagation may still be returning the previous A record for some networks.
Solution
Check the record using more than one DNS lookup tool and allow for TTL behaviour. If the old record persists too long, review the authoritative DNS provider.
The domain loads a server error or default hosting page
Likely cause
The A record may point to the correct IP address, but the server may not be configured to serve that domain.
Solution
Check the hosting account, virtual host, site binding or platform configuration so the server recognises the requested hostname.
The website loads but the browser shows a security warning
Likely cause
The domain may now point to a server without a valid SSL/TLS certificate for that hostname.
Solution
Issue or install the correct certificate, then test both the root and www versions of the domain over HTTPS.
A Record Change Checklist
Before changing an A record for a business website, review the surrounding setup. A planned change is safer than a rushed DNS edit.
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Confirm the correct destination IP address
Use the IP address supplied by the hosting provider or server administrator. Do not copy an address from an old record unless you know it is still correct.
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Check connected hostnames
Review the root domain, www version, staging subdomains, app subdomains and any third-party verification records that may be affected.
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Test the new environment before cutover
Confirm hosting, SSL/TLS, redirects, forms, analytics and important pages before sending live traffic to the new server.
Practical Guidance
Can You Change an A Record Yourself?
Dobble Approach
How We Approach A Records and DNS Management
A Record FAQs
These questions cover common points of confusion about A records, DNS changes and website hosting.
Is an A record the same as DNS?
Does an A record affect email?
How long does an A record change take?
Need Help Reviewing an A Record or DNS Setup?
If your domain, website, hosting or email setup is unclear, we can review the DNS configuration and explain what each record is doing before changes are made. This is especially useful before a launch, migration or provider change.