IPv6 Compatibility Checker — Website Test

Queries AAAA DNS records from authoritative name servers to verify whether a website or domain is reachable over IPv6.

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IPv6 Compatibility Checker — Verify AAAA DNS Records for Any Domain

A website IPv6 compatibility checker determines whether a domain publishes DNS AAAA records mapping its hostname to a 128-bit IPv6 address, as defined in RFC 3596. The tool queries the domain's authoritative name servers directly — not a recursive resolver — returning the live DNS state without cache interference. Results confirm whether the domain is reachable over the IPv6 protocol (RFC 8200) or accessible via IPv4 only.

Fact	Detail
IPv6 record type	AAAA (Quad-A) — defined in RFC 3596
IPv6 address size	128 bits — 2¹²⁸ total addresses (RFC 8200)
IPv4 record type	A record — 32-bit address, ~4.3 billion total
Query method	Authoritative DNS — no recursive resolver cache
Global IPv6 adoption	~45% of traffic to Google delivered over IPv6 (2026)

How to Use the Website IPv6 Compatibility Checker

Find out whether a domain publishes AAAA DNS records — the requirement for IPv6 reachability.

Enter the Domain Name

Type the domain name you want to test (e.g., google.com). The tool automatically strips http://, https://, www., and any trailing path.

Submit the Check

Click 'Check IPv6 Support'. The tool queries the domain's authoritative DNS name servers directly for AAAA records — bypassing resolver cache.

Read the IPv6 Result

A green SUPPORTED result confirms at least one AAAA record exists at the domain's authoritative name servers. NOT SUPPORTED means only IPv4 A records are published.

Take Action on the Result

If NOT SUPPORTED, contact your hosting provider or DNS registrar to add AAAA records pointing to your IPv6-enabled server address.

What the IPv6 Compatibility Result Means

Result	Meaning	What to Do
SUPPORTED	At least one valid AAAA record exists at the domain's authoritative name servers. The domain is IPv6-reachable.	Use the DNS Lookup tool to view the actual IPv6 addresses. Verify end-to-end connectivity with `curl -6 https://yourdomain.com`.
NOT SUPPORTED	No AAAA records found at the domain's authoritative name servers. The domain is IPv4 only.	Contact your hosting provider to obtain an IPv6 address, then add an AAAA record in your DNS control panel.

How the IPv6 Compatibility Check Works

DNS AAAA records were introduced in RFC 3596 (1998) to extend the Domain Name System for IPv6. The record type is named AAAA because an IPv6 address (128 bits) is four times the size of an IPv4 address (32 bits), which is stored in an A record.

This tool queries the domain's authoritative name servers directly, not a recursive resolver such as Google (8.8.8.8) or Cloudflare (1.1.1.1). The difference matters: recursive resolvers cache responses for the duration of the record's TTL. An authoritative query reflects the current published DNS state immediately, making it accurate even when a TTL has not yet expired across the resolver network.

The authoritative name servers for any domain are discovered by first performing an NS record lookup, then querying those name servers directly for the AAAA record — the same two-step process used by the DNS protocol when no cached answer is available.

A SUPPORTED result means at least one AAAA record resolves to a non-null 128-bit IPv6 address. It confirms DNS-layer IPv6 configuration but does not guarantee end-to-end TCP connectivity — the server itself must be bound to the IPv6 address and the upstream network must route IPv6 traffic to it.

Do it yourself

How to Check AAAA Records Without an Online Tool

The same AAAA record check can be performed from the command line on any platform. Note that the commands below query a recursive resolver by default — results may differ briefly from this tool when DNS changes have been made recently and the TTL has not expired.

Windows Command Prompt

nslookup -q=AAAA google.com

Windows PowerShell

Resolve-DnsName google.com -Type AAAA

Mac / Linux dig

dig google.com AAAA

Authoritative Query (matches this tool's behavior)

# Step 1: Find the authoritative name servers
dig google.com NS +short

# Step 2: Query one of them directly for the AAAA record
dig @ns1.google.com google.com AAAA

This tool queries authoritative name servers using the two-step method shown above — results reflect the live DNS state rather than a cached recursive resolver answer.

Common Uses for an IPv6 Compatibility Checker

Verifying hosting migration. A sysadmin migrates a web server to a new hosting provider that supports dual-stack networking. After adding AAAA records in the DNS control panel, the admin uses this tool to confirm the authoritative name servers are returning the new IPv6 address before updating the TTL or informing clients.

IPv6 proxy and CDN debugging. A developer routes traffic through a CDN that claims IPv6 support. The CDN's edge IP has an AAAA record, but the origin server does not. Using this tool on both the CDN hostname and the origin hostname separately confirms exactly where the IPv6 chain breaks, narrowing the troubleshooting scope to the origin configuration.

Pre-launch IPv6 compliance check. A web team preparing to launch a new domain has received a hosting plan that includes IPv6. Before going live, they use this tool to confirm the AAAA records are correctly published at the authoritative name servers — catching a misconfiguration before it affects real users connecting over an IPv6-only mobile network.

Frequently Asked Questions

What is a website IPv6 compatibility checker?

A website IPv6 compatibility checker queries a domain's DNS AAAA records to determine whether the domain is reachable over the IPv6 protocol (RFC 8200). AAAA records, defined in RFC 3596, map hostnames to 128-bit IPv6 addresses. If at least one valid AAAA record is published at the domain's authoritative name servers, the domain is IPv6-compatible.

What is a DNS AAAA record?

A DNS AAAA record (pronounced 'Quad-A') maps a hostname to a 128-bit IPv6 address, as defined in RFC 3596. It is the IPv6 equivalent of an A record, which maps hostnames to 32-bit IPv4 addresses. When a browser or client connects to a domain using IPv6, it resolves the AAAA record to obtain the server's IPv6 address. A domain with no AAAA record is reachable via IPv4 only.

My domain has AAAA records but is still unreachable over IPv6 — why?

A published AAAA record confirms DNS-layer IPv6 configuration, but does not guarantee end-to-end IPv6 connectivity. Common causes of unreachability despite a valid AAAA record include: the server's network interface is not bound to the IPv6 address in the record; the upstream router or hosting provider does not route IPv6 to the server; a firewall blocks inbound IPv6 traffic on port 80 or 443; or the AAAA record value is incorrect (typo or stale entry). Verify the server is listening on the IPv6 address using curl -6 https://yourdomain.com from an IPv6-enabled host.

What is the difference between an A record and an AAAA record?

An A record maps a hostname to a 32-bit IPv4 address (e.g., 93.184.216.34), while an AAAA record maps a hostname to a 128-bit IPv6 address (e.g., 2606:2800:21f:cb07:6820:80da:af6b:8b2c). Both record types are defined by RFC 1034 and RFC 1035; RFC 3596 extends the standard to define the AAAA type. A domain can publish both record types simultaneously, allowing clients to connect via whichever protocol their network supports — modern clients prefer IPv6 when both are available.

Do you store the domain names I check?

No. Domain names submitted to the IPv6 compatibility checker are queried against authoritative DNS name servers in real time and are not logged or stored. The result is returned directly to your browser. No user data, IP addresses, or queried domains are retained after the response is delivered.

How do I add AAAA records to enable IPv6 for my domain?

To add AAAA records, your server must first have an IPv6 address assigned by your hosting provider. Once you have the IPv6 address, log in to your DNS registrar or DNS hosting provider's control panel and add a new AAAA record with your hostname (e.g., @ for the root domain or www for the www subdomain) and the IPv6 address as the value. Set the TTL to 3600 seconds (1 hour) initially. After saving, use this tool to confirm the AAAA record is visible at your authoritative name servers.

Related Guides

Guide What Is IPv6?

The 128-Bit Internet Protocol Explained. A complete guide to IPv6 addressing, the AAAA record type, dual-stack networking, and the transition from IPv4 as defined in RFC 8200.

Guide What Is IPv4?

Understanding the 32-Bit Internet Protocol. Explains IPv4 addressing, A records, CIDR notation, and why IPv4 address exhaustion is driving the global adoption of IPv6.