ToyTools Guide
How to Convert an IPv4 Address
How a dotted IPv4 address becomes a 32-bit integer, padded hex, and binary, and why 256 and IPv6 are rejected.
How do you convert an IP address to an integer?
Type the dotted address. An ip to decimal conversion, an ipv4 to decimal reading, and an ip to hex reading are the same 32 bits. The page returns four writings of that one host: dotted decimal, the unsigned 32-bit integer, hex with eight digits, and binary with a dot between each octet. 192.168.0.1 is 3232235521, 0xC0A80001, and 11000000.10101000.00000000.00000001. Any of those four inputs produces the other three.
An IPv4 converter here is that translation and the refusals around it. 256 in an octet is not wrapped. An IPv6 address is not cut down. A string of digits that is also four octets glued together is shown as an integer and, when only one split fits, offered as the dotted address. The subnet math lives on the CIDR calculator.
Open the IPv4 Converter →How does a dotted address become 32 bits?
Each octet is eight bits. The first octet is shifted 24 bits, the second 16, the third 8, and the last octet stays where it is. Those four pieces are added as an unsigned value. 192 is 0xC0, 168 is 0xA8, 0 is 0x00, 1 is 0x01, so the hex form is 0xC0A80001 and the decimal form is 3232235521. The same steps run backwards from a decimal, from 0x hex, or from 32 binary digits.
Why hex from a packet capture keeps leading zeros is a column-width problem. The hex form always has eight digits. For example, input: 10.0.0.1. Output: 0x0A000001, not 0xA000001. Packet captures print the wide form, and a shorter string fails a visual compare even when the integer matches. Dotted decimal versus a 32-bit integer is only a change of spelling. Binary is grouped in eights for the same reason: the octet boundaries are the thing a person checks.
Why is an octet above 255 rejected?
An octet is defined as 0 to 255. 256.1.1.1 does not name a host. Some converters accept a generic integer in each slot and let 256 spill into the next octet, which silently produces a different address from the text on the screen. This page names the number that is outside 0 to 255 and shows no result. There is nothing useful to offer as a replacement, because the typed text was not an address.
A decimal integer has its own range: 0 to 4294967295, which is 255.255.255.255. A longer number is rejected. A leading zero on a decimal is rejected too, so 0127 is not quietly read as octal or as 127. Use a dotted address, or prefix hex with 0x.
What happens when the paste is IPv6?
2001:db8::1 is IPv6. Cutting characters off the front or the end can leave a string that looks a bit like an IPv4 fragment, and that fragment is the wrong host. The page says the paste is IPv6 and was not cut down. There is no dotted result and no button.
What an IPv4-mapped IPv6 address contains is the four octets after ::ffff:. ::ffff:192.0.2.1 and the hex form ::ffff:c000:0201 both carry 192.0.2.1. The page still refuses to pretend the whole paste was IPv4. It names the embedded address and offers it as a one-tap fill. After the tap, the four spellings are the spellings of 192.0.2.1 only.
Why does 8888 offer 8.8.8.8?
Digits with no dots are read as one integer. 8888 is the host 0.0.34.184. The same digits split only one way into four octets from 0 to 255: 8.8.8.8, which is a different host (134744072). People glue octets when they are moving fast. Showing only the integer would confirm the wrong host. The page shows 0.0.34.184 and offers 8.8.8.8.
19216811 is the case where a guess would be worse. More than one split fits, and 192.168.1.1 is only one of them. The page shows the integer reading, lists a few splits, and does not pick. Add the dots yourself. A dotted address, including 8.8.8.8 after you accept the offer, does not show the note. The decimal 3232235521, which is 192.168.0.1 written properly as an integer, does not show it either.
What should you open next?
Matching a firewall log integer to the dotted address an operator expects is the job this page finishes. When the question is the network rather than the host, paste the dotted form into the CIDR calculator. A /24 of 192.168.0.1 is the network 192.168.0.0, mask 255.255.255.0. This page will not invent that mask for you.
Binary outside an address, or hex of a string that is not an address, belongs on the binary converter and the hex encoder. Those tools do not know about octets, and they should not. An address that is only a number is finished here.
Convert 192.168.0.1 →Related Tools
You May Also Need
You may also need
- CIDR CalculatorTake the dotted address onward into a subnet, mask, and wildcard
Next steps
- Binary ConverterRead a number as binary outside an IPv4 address
- Hex Encoder and DecoderEncode text as hex when the value is not an address