IPv4 / IPv6 Converter

Convert, validate, and transform IP addresses - decimal, binary, IPv4-mapped IPv6, expand/compress.

Last reviewed: June 2026

Reviewed by Shannon Patterson, software engineer · last updated June 2026

New to this tool? Click here for instructions

Enter an IP address above.

How to Use the IPv4 / IPv6 Converter

Use the mode chips to choose the specific IP task you need: IPv4-mapped IPv6 conversion, decimal conversion, binary octets, or validation. Paste an address into the active field and the result grid updates as you type.

Use IPv4 <-> IPv6 to create or inspect IPv4-mapped IPv6 notation.
Use Decimal to convert between dotted IPv4 and its unsigned 32-bit integer value.
Use Binary to view each IPv4 octet as an 8-bit value.
Use Validate to classify common IPv4 ranges such as private, loopback, and link-local.

When to Use the Tool in Real Workflows

The converter is useful when checking firewall allowlists, translating stored integer IP values, explaining CIDR calculations, reviewing logs, and validating whether a sample IPv4 address belongs to an RFC 1918 private range.

How It Works

The parser and converters run entirely in the browser. IPv4 values are split into four decimal octets and converted with 32-bit arithmetic. IPv6 inputs are expanded to eight hextets, compressed again with the longest zero run, and inspected for the IPv4-mapped prefix. No address is uploaded to an external service.

Useful references: RFC 791 for IPv4, RFC 4291 for IPv6 addressing architecture, RFC 5952 for IPv6 text representation, and RFC 1918 for private IPv4 ranges.

Tips, Edge Cases, or Limitations

The decimal and binary modes are IPv4-focused because they operate on a 32-bit address.
IPv4 octets with leading zeros are rejected to avoid ambiguous legacy interpretations.
The validator classifies common IPv4 ranges; it is not a full routing-policy or threat-intelligence lookup.
IPv6 scope IDs, zone identifiers, and CIDR suffixes should be removed before using this page.

Frequently Asked Questions

An IPv4-mapped IPv6 address represents an IPv4 address within the IPv6 address space. It has the form ::ffff:x.x.x.x. For example, 192.168.1.1 maps to ::ffff:192.168.1.1. This is used in dual-stack networking so IPv6 sockets can communicate with IPv4 hosts.

IPv4 uses 32-bit addresses (4.3 billion possible), written as four decimal octets (e.g. 192.168.1.1). IPv6 uses 128-bit addresses (340 undecillion possible), written as eight groups of four hex digits (e.g. 2001:db8::1). IPv6 was created to address IPv4 exhaustion.

Two rules: leading zeros in each group can be omitted, and one sequence of all-zero groups can be replaced by ::. So 2001:0db8:0000:0000:0000:0000:0000:0001 compresses to 2001:db8::1.

An IPv4 address is a 32-bit integer. The decimal = A * 16777216 + B * 65536 + C * 256 + D. For example, 192.168.1.1 = 3232235777. This is used in database storage and IP range calculations.

Private IPv4 ranges (RFC 1918): 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. Loopback: 127.0.0.0/8. Link-local: 169.254.0.0/16. Any address outside these is public (routable on the internet).

Quick reference

IPv4 / IPv6 Converter — quick reference
Aspect	Detail
Purpose	IPv4 / IPv6 Converter is a free browser tool for fast, repeatable tasks.
Runs in	Any modern browser — no install, no signup.
Privacy	Data is processed locally in your browser; no upload to any server.
Best for	Quick lookups, daily reference, learning, prototyping.

Example walk-through

Convert an IPv4 address to mapped IPv6 and decimal form

Step 1. In IPv4 <-> IPv6 mode, enter 192.0.2.1.

Step 2. The tool recognizes a valid IPv4 address and displays the IPv4-mapped IPv6 form.

IPv4-mapped IPv6: ::ffff:192.0.2.1
IPv6 full form: 0000:0000:0000:0000:0000:ffff:c000:0201

Step 3. Switch to Decimal mode and enter the same IPv4 address.

192.0.2.1 = 3221225985

The decimal value comes from 192 * 16777216 + 0 * 65536 + 2 * 256 + 1.