IPv4 vs IPv6: What's the Difference?
Two versions of the internet's addressing system are running side by side right now. Here's how to tell them apart at a glance — and why the world is slowly moving from one to the other.
Telling them apart at a glance
The fastest way to tell IPv4 and IPv6 apart is simply how they're written:
# IPv4 — four numbers, 0–255, separated by dots 192.168.1.1 203.0.113.42 # IPv6 — eight groups of hexadecimal, separated by colons 2606:4700:4700:0000:0000:0000:0000:1111 2606:4700:4700::1111 # the :: hides the empty groups
If you see dots, it's IPv4. If you see colons and letters mixed with digits, it's IPv6. The double colon (::) is shorthand for one or more all-zero groups, which is why real-world IPv6 addresses often look short.
Why IPv6 exists
IPv4 was designed in the late 1970s with a 32-bit address field — about 4.3 billion possible addresses. In 1980 that seemed inexhaustible; today there are more internet-connected devices than people on Earth.
The internet patched the shortage for decades with tricks like NAT (whole households sharing one public IPv4) and CGNAT (entire neighbourhoods sharing one). But patching has limits, so in 1998 the IETF standardised IPv6: a 128-bit address space offering roughly 340 undecillion (3.4 × 10³⁸) addresses — enough to give every device on the planet billions of addresses of its own.
Side-by-side comparison
| Feature | IPv4 | IPv6 |
|---|---|---|
| Format | 203.0.113.42 | 2606:4700::1111 |
| Size | 32-bit | 128-bit |
| Address space | ≈ 4.3 billion | ≈ 3.4 × 10³⁸ |
| Separators | Dots (.) | Colons (:) |
| NAT needed | Yes — addresses are scarce | No — every device can have a public address |
| Configuration | Manual or DHCP | Automatic (SLAAC) or DHCPv6 |
| Adoption | Universal | ≈ 45%+ of Google users and climbing |
Which one are you using?
Most likely both. Modern networks run dual stack — IPv4 and IPv6 side by side — and your device picks the best one per website. Our homepage shows each one separately: the IPv4 and IPv6 badges under your address say Detected when your connection has that protocol, and Not detected when it doesn't.
Open howtofindtheip.com and look at the connectivity chips. If IPv6 says "Not detected", your ISP hasn't enabled it yet (or your router has it switched off) — nothing is broken, and IPv4 keeps working fine.
Test tip: the address shown big at the top of the page is whichever protocol your browser preferred for that request. If it contains colons, you reached us over IPv6 — a working IPv6 connection in action.
How the switch is going
IPv6 adoption passed 45% of Google's user base and continues to grow every year. India, the US, France and Germany are well past 50%; mobile carriers in particular have embraced it. Full replacement of IPv4 will take years more, because the two protocols are not directly compatible — hence dual stack, and translation technologies for the awkward in-between period.
For you as a user, the transition is invisible: same internet, same sites, just roomier addresses underneath. For the internet as a whole, it's the difference between a crowded city and infinite suburbs.
Learn more
- New to the topic? Start with what an IP address actually is.
- Want the numbers for your own connection? Check your IP now.
- On a device hunt? See how to find the IP address on Windows, Mac, iPhone and Android.
IPv4 vs IPv6 questions
Which is better, IPv4 or IPv6?
For users, neither is "faster" in any noticeable way. IPv6 is the future-proof protocol with a practically unlimited address space and simpler routing; IPv4 remains universal because every network supports it. Ideally your connection runs both.
Why do I have an IPv4 and an IPv6 address at the same time?
Most modern networks run "dual stack": both protocols are active simultaneously. Which one is used for a given website depends on what that site supports. Our homepage detects each of your addresses separately.
Is IPv6 more private than IPv4?
Not necessarily. An IPv6 address can contain a stable interface identifier that stays with your device, which in theory makes it more trackable. Modern operating systems use privacy extensions that randomise this identifier, so in practice IPv6 is roughly comparable to IPv4 for privacy.
Do I need to do anything to switch to IPv6?
Usually no. IPv6 arrives automatically once your ISP enables it and your router supports it. If the IPv6 badge on our homepage says "Not detected", either your ISP hasn't rolled it out yet or your router has it disabled.