Address space and format
IPv4 uses 32-bit addresses, usually written as four decimal numbers. Its limited address space led to widespread address sharing.
IPv6 uses 128-bit addresses, written in hexadecimal groups. It provides a far larger pool of addresses.
The longer IPv6 format is normal and does not by itself indicate a security problem.
Why both protocols are still used
Many networks run dual stack, meaning a device can connect over either IPv4 or IPv6. The chosen route can vary by destination and network policy.
IPv4 remains necessary for older systems and networks that have not adopted IPv6.
Translation mechanisms can connect IPv6-only and IPv4-only parts of the internet when direct dual-stack access is unavailable.
IPv6 and privacy
IPv6 addresses can be assigned dynamically and may use temporary addressing features. Address behavior depends on the operating system and network operator.
An IPv6 address is not automatically more revealing than IPv4. Websites still see the address used for a given connection.
Privacy also depends on browser settings, accounts, cookies, and other signals beyond the network protocol.
Test your IPv6 connection
An IPv6 test can confirm whether a browser reaches an IPv6-capable endpoint. A failed test may reflect network availability, filtering, or browser policy.
Checking both protocols is useful when diagnosing why one service connects differently from another.
- Test an IPv4 and an IPv6 endpoint from the same browser.
- Record whether a failure is limited to one protocol or destination.
IPv4: 198.51.100.25
IPv6: 2001:db8:85a3::8a2e:370:7334