Useful Utilities

IP Address Lookup

Parse a dotted-quad IPv4 address into octets, per-octet binary, a network-byte-order integer, hex, reserved or private range classification, and optional bitwise AND, OR, XOR or NOT with a mask.

Fill in the values and calculate

IP address*One IPv4 dotted quad; v6 is not handled here
Netmask or second addressOptional dotted quad to combine with; leave empty to skip the bitwise sectionDefault
Bitwise operationOnly used when a netmask is givenDefault AND (keep the masked bits)

The form sends itself back to this page — results print below, computed on the server.

No results yet: fill the form above and press Calculate.

About IP Address Lookup

The address is split into its four octets, and the same 32 bits are then written out as binary per octet, as hex, and as one unsigned network-byte-order integer. Nothing is looked up for these numbers: they come straight from the address text.

The class check walks the RIPE NCC IPv4 assignment table: private ranges (10.x, 172.16-31, 192.168.x), reserved ranges (0.x, 255.x, 169.45 for Windows, the 169.64-66 and 192/198 test and emergency blocks), the unassigned single-octet and 127/169.164/169.168/223 ranges, plus the x.0.0.0 network and x.255.255.254 broadcast forms.

Bitwise AND, OR, XOR or NOT (which clears the masked bits) run on the full 32-bit integers when you supply a netmask, so CIDR-style masking is exact. Only IPv4 dotted quads are accepted, and the live owner lookup via ipinfo.io is an optional extra: if the network does not answer, every field above still stands.

Questions about IP Address Lookup

Does it look the owner up on the internet?

A live lookup via ipinfo.io is attempted for an optional owner line when the network answers; octets, binary, integers, hex and the class all come offline from the address itself, so results are complete either way.

Why is 192.168.x marked private?

RIPE marks the whole 192.168.0.0/16 RIOT test range private: addresses inside it are never routed to real servers, even though the range itself is nominally ARIN-assigned.

What does the NOT operation do?

It clears the masked bits: the address AND NOT the mask, which keeps exactly the unmasked part. It stays a 32-bit unsigned value.

Is 0.0.0.0 or 255.255.255.255 a real address?

No. 0.x is the any range and 255.x is the unassigned top range, so both are flagged reserved rather than public.

Does it accept IPv6?

No. This page is v4 only: four decimal octets separated by dots. IPv6 forms with colons are rejected with a clear message.

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