BYTETOOLS

Private IP Address Checker

Check if an IPv4 or IPv6 address is private, loopback, link-local, CGNAT or otherwise special — with the matching RFC and public-routability verdict.

Classification

192.168.1.50 is NOT routable on the public internet — it belongs to the Private network range.
Address
192.168.1.50
Family
IPv4
Matched range
192.168.0.0/16
Range purpose
Private network
Defined in
RFC 1918

Special-purpose ranges checked

RangePurposeRFCPublic internet
255.255.255.255/32Limited broadcastRFC 919not routable
192.0.2.0/24Documentation (TEST-NET-1)RFC 5737not routable
198.51.100.0/24Documentation (TEST-NET-2)RFC 5737not routable
203.0.113.0/24Documentation (TEST-NET-3)RFC 5737not routable
192.0.0.0/24IETF protocol assignmentsRFC 6890not routable
192.88.99.0/246to4 relay anycast (deprecated)RFC 7526routable
192.168.0.0/16Private networkRFC 1918not routable
169.254.0.0/16Link-local (APIPA)RFC 3927not routable
198.18.0.0/15Network benchmarkingRFC 2544not routable
172.16.0.0/12Private networkRFC 1918not routable
100.64.0.0/10Carrier-grade NAT (CGNAT)RFC 6598not routable
0.0.0.0/8"This network" / unspecifiedRFC 791not routable
10.0.0.0/8Private networkRFC 1918not routable
127.0.0.0/8LoopbackRFC 1122not routable
224.0.0.0/4Multicast (class D)RFC 5771not routable
240.0.0.0/4Reserved for future use (class E)RFC 1112not routable
::/128Unspecified addressRFC 4291not routable
::1/128LoopbackRFC 4291not routable
::ffff:0:0/96IPv4-mapped IPv6RFC 4291not routable
64:ff9b::/96NAT64 well-known prefixRFC 6052routable
100::/64Discard-only prefixRFC 6666not routable
2001:db8::/32DocumentationRFC 3849not routable
2002::/166to4RFC 3056routable
fc00::/7Unique local address (ULA)RFC 4193not routable
fe80::/10Link-localRFC 4291not routable
ff00::/8MulticastRFC 4291not routable

What is the Private IP Address Checker?

The Private IP Address Checker classifies any IPv4 or IPv6 address against the complete table of special-purpose ranges: RFC 1918 private blocks (10/8, 172.

  • Covers all RFC 1918 private ranges plus 12 more IPv4 special blocks
  • IPv6 aware: loopback, ULA, link-local, multicast, documentation, NAT64
  • Clear public-internet routability verdict for every address
  • Names the exact matching CIDR range and its defining RFC
  • Built-in reference table of every range checked
  • Static local lookup — no geolocation, no lookups, no tracking

How to use the Private IP Address Checker

  1. 1

    Type or paste an IPv4 or IPv6 address.

  2. 2

    Read the verdict: public and routable, or the special range it belongs to.

  3. 3

    Check the matched range's purpose and defining RFC in the details panel.

  4. 4

    Browse the full special-purpose range table below for reference.

About the Private IP Address Checker

The Private IP Address Checker classifies any IPv4 or IPv6 address against the complete table of special-purpose ranges: RFC 1918 private blocks (10/8, 172.16/12, 192.168/16), loopback, link-local/APIPA, carrier-grade NAT (100.64/10), documentation and benchmarking ranges, multicast, and the IPv6 equivalents — ULA fc00::/7, link-local fe80::/10, and more.

For each address you get a plain-English verdict: whether it is routable on the public internet, which reserved range it matched, what that range is for, and the RFC that defines it. The full reference table of every range checked is shown underneath, so the tool doubles as a cheat sheet.

Classification is a static range-table lookup computed locally in your browser — there is no geolocation, no WHOIS and no network traffic of any kind.

Frequently asked questions

What are the private IP address ranges?

RFC 1918 reserves three IPv4 blocks for private networks: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. Addresses in these ranges are never routed on the public internet, which is why every home router can use 192.168.1.1 simultaneously.

Is 100.64.x.x a private IP address?

Not exactly — 100.64.0.0/10 is the carrier-grade NAT (CGNAT) shared address space from RFC 6598. ISPs use it between customer routers and their own NAT infrastructure. It behaves like private space but is reserved specifically so it never collides with customers' RFC 1918 networks.

What is the difference between 127.0.0.1 and 169.254.x.x?

127.0.0.1 is loopback — traffic to it never leaves your machine. 169.254.0.0/16 is link-local (APIPA): a machine assigns itself one of these when DHCP fails, and the address only works on the local network segment. Seeing one usually signals a DHCP problem.

What are the IPv6 equivalents of private addresses?

Unique Local Addresses (fc00::/7, in practice fd00::/8) are the IPv6 analogue of RFC 1918 space, and fe80::/10 is link-local, automatically present on every IPv6 interface. ::1 is the loopback, equivalent to 127.0.0.1.

Does this tool tell me where an IP address is located?

No. It classifies addresses purely against the published IANA/RFC special-purpose registries using local math — no geolocation database is involved and no query is sent. For a public address it can only say "routable on the internet", not where it is.

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