IPv4 vs IPv6
Differences, use cases, and when to use each
IPv4 uses 32-bit addresses (4.3 billion, nearly exhausted). IPv6 uses 128-bit addresses (340 undecillion) to solve address exhaustion. Both protocols coexist during the ongoing transition.
Quick Comparison
| Feature | IPv4 | IPv6 |
|---|---|---|
| Address Size | 32-bit | 128-bit |
| Total Addresses | ~4.3 billion | ~340 undecillion |
| Format | 192.168.1.1 | 2001:db8::1 |
| NAT Required | Yes (address conservation) | No (enough addresses) |
| Adoption | ~65% of internet | ~35% of internet |
When to Use Each
When to Use IPv4
IPv4 remains the dominant protocol. Use IPv4 when compatibility with all networks and devices is essential.
When to Use IPv6
Use IPv6 for new network infrastructure and when future-proofing. IPv6 adoption is growing, and many mobile networks are IPv6-only.
Pros & Cons
IPv4
Universal support
Simple address format
Well-understood
Address exhaustion
NAT complexity
IPv6
Unlimited addresses
No NAT needed
Built-in security
Better routing
Not universally supported yet
Complex address format
Verdict
Support both (dual-stack) for new applications. IPv4 isn't going away soon, but IPv6 adoption is accelerating as IPv4 addresses become increasingly scarce.