Network Health
IPv6 Test
Which address family your connection actually used to reach this server, and what that does and does not tell you about IPv6 support.
Preparing checks…
How this works
The server records which address family your request arrived on and which address it came from. Both families are probed independently so that the two results can be compared rather than inferred from one another.
Input
- No input required
Output
- The address family the server observed
- Your IPv6 address, if one was used
- Your IPv4 address, if one was used
- A dual-stack assessment
Privacy
The address is used only to produce the result on this page. It is not logged, not stored, and not placed in the URL.
Limitations
- Arriving over IPv4 does not prove IPv6 is unavailable; the browser may have preferred IPv4.
- A dual-stack connection can use either family depending on the destination and DNS answers.
- This tests reachability to this server only, not to the internet as a whole.
- Some networks tunnel IPv6, which this test cannot detect.
Frequently asked questions
What is IPv6?
It is the successor to IPv4, using 128-bit addresses instead of 32-bit ones. It removes the address shortage that made network address translation necessary.
What does dual-stack mean?
It means a connection has both IPv4 and IPv6 available and can use either. Which one is used for a given request depends on DNS and routing.
Why does this say IPv6 was not observed?
Either there is no IPv6 route, or your browser chose IPv4 for this request. A single observation cannot distinguish those, so the result is reported as unknown rather than as a failure.