IPv4 vs IPv6: What’s the difference?
The internet uses IP addresses to identify devices. IPv4 is the legacy format with ~4.3 billion addresses; IPv6 is the modern replacement with a vastly larger address space and several technical improvements. This article explains formats, benefits, migration notes and practical checks you can run with MyIPScan tools to see what your connection uses.
Quick comparison: IPv4 vs IPv6
| Feature | IPv4 | IPv6 |
|---|---|---|
| Address format | Decimal dotted quad (e.g., 203.0.113.7) |
Hexadecimal colon-separated (e.g., 2001:db8::1) |
| Address space | ~4.3 billion addresses | ~3.4×1038 addresses (practically unlimited) |
| Built-in features | Limited; NAT commonly used | Auto-configuration, no NAT required, improved routing |
| Migration complexity | Widespread legacy infrastructure | Requires dual-stack or transition tech; not instantaneous |
| User impact | Works everywhere today | Progressive rollout; benefits when both endpoints and network support IPv6 |
Why IPv6 matters
IPv6 solves the address shortage and simplifies some network functions. It enables direct addressing for devices (better end-to-end connectivity), reduces reliance on NAT translation, and includes improvements for routing and autoconfiguration. For new services and IoT growth, IPv6 is essential — but the transition is gradual: IPv4 and IPv6 will operate side-by-side for many years.
Should you enable IPv6 on your device?
For most home users: if your ISP provides IPv6 and your router supports it, enabling IPv6 is generally safe and future-proof. Test after enabling: visit Check IP to see which address shows up publicly. If you rely on specific corporate VPNs, check compatibility first.
How to check (quick checklist)
- Open Check IP — see if your public IP is IPv4, IPv6, or both.
- Run the WebRTC Leak Test to ensure the browser doesn't expose local addresses.
- Run DNS Lookup — confirm resolvers and whether DNS queries travel over IPv4 or IPv6.
- If you see issues, temporarily disable IPv6 on the OS/router and re-test to compare behavior.
Common migration scenarios & tips
Enterprises and ISPs use dual-stack (both IPv4 and IPv6), tunneling, and translation mechanisms during migration. If you manage a small network:
- Enable dual-stack on devices that support it.
- Ensure firewall rules include IPv6 addresses and rules (they are separate from IPv4 rules).
- Update monitoring and logging to capture IPv6 traffic.
Frequently asked questions
1. When will IPv4 stop working?
There is no single “IPv4 shutdown” date. IPv4 will remain in use for the foreseeable future; the shift to IPv6 is incremental and coordinated by ISPs and large providers.
2. Can IPv6 improve privacy?
IPv6 itself doesn't guarantee privacy. Some IPv6 addresses can be stable identifiers if you don't use privacy extensions. Use privacy settings and trusted VPNs when privacy is a concern.
3. I have problems after enabling IPv6 — what then?
Check router firmware and ISP guides. If problems persist, disable IPv6 temporarily and contact your ISP or network admin. Also verify firewall rules for IPv6.
Try it now: run our Check IP, then test WebRTC and DNS Lookup to verify exactly what your connection exposes.