Will IPv4 be turned off?

No imminent global shutdown. IPv4 and IPv6 coexist (dual stack). New networks favor IPv6, but content and eyeball networks still maintain IPv4 for compatibility.

Why are IPv4 addresses 'running out'?

IPv4 uses 32-bit addresses (~4.3B theoretical). NAT and private ranges stretched lifespan, but IPv6’s 128-bit space removes the scarcity problem at the edge.

Does IPv6 improve speed?

Not inherently. Latency and throughput depend on routing, peering, and last-mile tech. IPv6 can avoid some NAT hairpins, but user experience is dominated by other factors.

April 18, 2026 · 11 min read

IPv4 vs IPv6 Explained: What's the Difference and Which Are You Using?

A practical comparison of address formats, NAT, adoption in 2026, and how to tell which protocol your connection prefers.

The internet runs on numbered endpoints. IPv4 has been the workhorse since the 1980s; IPv6 fixes scale and simplifies some routing ideas — but migration is incremental. If you have ever seen 192.168.1.10 on your laptop, that is private IPv4 behind your router. If you visit a “what is my IP” page and see something like 203.0.113.44, that is public IPv4. IPv6 public addresses look longer: 2001:db8:abcd:0012::1.

Address size and notation

Topic	IPv4	IPv6
Length	32 bits	128 bits
Typical notation	Dotted decimal	Hex groups with `::` compression
Example (public)	`203.0.113.44`	`2001:db8::ff`

IPv6 allows leading-zero omission and a single :: per address to replace a run of zero groups — handy for human reading, occasionally confusing for beginners.

NAT: why IPv4 survived so long

Most homes get one public IPv4 from an ISP. The router performs Network Address Translation, mapping many private 192.168.x.x clients to that single public address using port tuples. IPv6 was designed so devices could have globally routable addresses without NAT at the edge (though firewalls still matter). In practice, many networks still deploy IPv6 alongside IPv4.

Header differences (what practitioners care about)

IPv6 drops some IPv4 fields (no header checksum; fixed 40-byte base header) and uses extension headers for options. Fragmentation is expected to happen at the source. For day-to-day users, the important takeaway is tooling and visibility: traceroute, firewalls, and logs must understand both families.

How to know what you are using

Run our IP tool — if you see an IPv6-shaped address, your path to that service preferred IPv6 (or only IPv6).
On desktop, ipconfig / ifconfig / ip addr show per-interface addresses.
Browser WebRTC leaks (when not disabled) historically exposed local candidates — a separate privacy topic from protocol choice.

Security myths

IPv6 is not “more secure” by default. IPsec was baked into the original story, but widespread transport encryption comes from TLS on top of either protocol. Firewall policy must explicitly cover IPv6; a host “only thinking about v4” can be a blind spot.

2026 reality

Major mobile networks and ISPs ship dual stack. Content networks serve AAAA (IPv6) and A (IPv4) DNS records. Enterprise networks sometimes lag on internal IPv6 even when the WAN supports it. As an end user, you rarely choose — your OS and router negotiate paths.

When you need a plain-language snapshot of the address the internet associates with your session, jump to our live checker and compare before/after toggling VPN or tethering.