Convert an IPv4 address between dotted-decimal and binary notation, either direction.
Every IPv4 address is really a 32-bit binary number — the familiar dotted-decimal form (like 192.168.1.1) is just a human-friendly way of writing four 8-bit groups (octets) as decimal numbers separated by dots. This tool converts between the two representations in either direction.
Seeing the binary form is genuinely useful for understanding subnetting: a subnet mask works by marking which bits are "network" bits, and that operation only makes real sense when you can see the actual 1s and 0s rather than the decimal shorthand. It's also a common troubleshooting step when working out whether two addresses are in the same subnet by eye.
Each octet converts independently (0-255 decimal maps to 00000000-11111111 binary), which is why every valid IPv4 octet fits in exactly 8 binary digits.
Worked example: 8.8.8.8 (Google's public DNS) converts to 00001000.00001000.00001000.00001000, since each octet is 8 in decimal, which is 00001000 in 8-bit binary (0 + 0 + 0 + 0 + 1×8 + 0 + 0 + 0, reading bit positions right to left as 1, 2, 4, 8, 16...). A larger octet like 192 (as in 192.168.x.x) becomes 11000000, and 168 becomes 10101000 — each octet's binary form is computed completely independently of the others, which is exactly why the four groups can be converted one at a time without needing to know the whole address first.
Each octet of an IPv4 address is one byte (8 bits), so it’s always padded to 8 binary digits — an octet of 1 is written as 00000001, not just 1, to keep every octet the same width.
Convert both addresses to binary, then compare only the bits covered by your subnet mask’s prefix length — if those leading bits match, the addresses are in the same subnet.
No — this version handles IPv4 (32-bit) addresses only. IPv6 addresses are 128 bits and written in hexadecimal groups rather than decimal octets, which is a different enough format that it needs its own conversion logic — not something this tool currently offers.