What's the valid range for the integer?

Any whole number from 0 to 4294967295 (2³²−1), the full range of an unsigned 32-bit integer. 0 maps to 0.0.0.0 and 4294967295 maps to 255.255.255.255.

How is the IPv4 address calculated?

The integer is divided by successive powers of 256 and each result is taken modulo 256 to recover one octet at a time: dividing by 16777216 gives the first octet, by 65536 gives the second, by 256 gives the third, and the remainder gives the fourth.

What happens if I enter a negative number or a decimal?

Both are rejected. Only whole, non-negative integers within the 32-bit unsigned range are valid input, since a negative value or fraction can't map to a byte of an IPv4 address.

Long to IP Converter - Integer to IPv4 Online

Overview

Introduction

Systems that store IP addresses as a plain integer, for compact storage or fast range comparisons, need a way to turn that number back into a readable address.

This tool does that conversion entirely in your browser, so nothing you paste is sent to a server.

What Is Long to IP Converter?

A converter that treats an unsigned 32-bit integer as an IPv4 address and reconstructs its familiar dotted-quad form.

It's part of this site's Network Tools collection and runs entirely client-side, and it's the exact inverse of the IP to Long Converter.

How Long to IP Converter Works

The integer is broken into four bytes using integer division and modulo by powers of 256: dividing by 16777216 and taking the result mod 256 gives the first octet, and so on down to the plain remainder for the last octet.

Each recovered byte is guaranteed to be between 0 and 255, so the output is always a well-formed dotted-quad address for any valid 32-bit input.

When To Use Long to IP Converter

Use it when a database, log file, or API returns an IP address as a raw integer and you need to read it as a normal address.

It's also useful for spot-checking the boundaries of a numeric IP range, like confirming what address a given upper or lower bound actually represents.

Often used alongside IP to Long Converter.

Features

Advantages

Exact, deterministic conversion for the entire valid 32-bit range.
Strictly validates the input, rejecting negative numbers, decimals, and anything above 4294967295.

Limitations

IPv4 only — a 128-bit IPv6 address can't be represented as a single 32-bit integer.
Doesn't indicate whether the resulting address is public, private, or reserved.

Examples

Converting an integer back to a documentation address

Input

3221225985

Output

192.0.2.1

3221225985 ÷ 16777216 = 192 remainder 2130433, which further decomposes to octets 0, 2, and 1.

Converting the maximum 32-bit value

Input

4294967295

Output

255.255.255.255

4294967295 is 2³²−1, the largest unsigned 32-bit integer, which maps to the broadcast address.

Best Practices & Notes

Best Practices

Use the IP to Long Converter to check the round trip when debugging a stored value.
Reject or flag values above 4294967295 upstream; they can't represent a valid IPv4 address.
Confirm which byte order a shared integer value assumes (network byte order is standard) before decoding it in a different system.

Developer Notes

The implementation uses Math.floor and the modulo operator on plain numbers rather than bitwise operators, since JavaScript's bitwise operators coerce to signed 32-bit integers and would misbehave for addresses at or above 128.0.0.0.

Long to IP Converter Use Cases

Reading an IP address back out of a database column stored as an integer
Converting a numeric bound from a firewall rule or geolocation table into a readable address
Verifying the round trip after converting an address to its integer form

Common Mistakes

Entering a signed integer that's actually negative after 32-bit overflow in another system, instead of its unsigned equivalent.
Assuming this works for IPv6 integers, which require 128 bits rather than 32.

Tips

Pair this with the IP to Long Converter to confirm a round trip when verifying stored data.

Long to IP Converter