Private IP Ranges
A quick reference to the private address spaces defined by RFC 1918 (IPv4) and RFC 4193 (IPv6 ULA). These ranges are non‑routable on the public internet and are typically used inside home and enterprise networks.
For a friendly introduction to private networks, see What Is an Intranet and the comparison Intranet vs Internet.
10.0.0.0/8 — Enterprise Network Backbone
The largest RFC 1918 allocation, commonly used by organisations that run campus-scale or multi-site networks. Its size generally allows extensive subnetting while keeping addressing internal and typically NATed at the perimeter.
172.16.0.0/12 — Mid-Size Corporate Space
A flexible private range often adopted for VPN pools and cloud VPCs. It generally strikes a balance between routability and address capacity, making it a good fit for many segmented business networks.
192.168.0.0/16 — Small Office and Residential LANs
Often the default choice for consumer and SMB routers. Many deployments carve out 192.168.0.0/24 or 192.168.1.0/24 to cover household devices, branch offices, and IoT segments.
fc00::/7 — IPv6 Unique Local Addresses
RFC 4193 defines this non-routable IPv6 space primarily for internal-only services. The locally assigned fd00::/8 prefix can enable dual-stack environments to mirror IPv4 private addressing strategies in many deployment scenarios.
Private Address Classification
Paste any IPv4 or IPv6 string to confirm whether it falls inside the RFC 1918 or IPv6 ULA allocations. The checker also flags loopback, link-local, and reserved ranges. Processing stays within the browser context, so no IP data is persisted beyond the session.