IPv4 to IPv6 Converter
Convert any IPv4 address to IPv6 format — or reverse it. Get IPv6 compressed, expanded, mapped, and 6to4 tunnel formats. Switch between IPv4 → IPv6 and IPv6 → IPv4 using the tabs below. Instant client-side conversion with full RFC compliance.
Free IP ToolIPv4 to IPv6 ConverterRFC CompliantClient-Side
What Is IPv4 to IPv6 Conversion?
IPv4 to IPv6 conversion is the process of representing a 32-bit IPv4 address (like 192.168.1.1) in the 128-bit IPv6 address format. This doesn't change the underlying network address — it creates an IPv6 representation that maps back to the same IPv4 endpoint, enabling communication between IPv4 and IPv6 systems.
With IPv4 address exhaustion — all 4.3 billion addresses have been allocated — the internet is transitioning to IPv6, which provides approximately 340 undecillion (3.4 × 10³⁸) addresses. During this transition, dual-stack networks must handle both protocols simultaneously, making IPv4 to IPv6 conversion essential for network administrators, developers, and IT professionals.
Our free converter supports both directions — IPv4 to IPv6 and IPv6 to IPv4 — using the tab switcher above. For IPv4 → IPv6, it generates five formats: compressed hex, shortened, fully expanded, mixed-notation mapped, and 6to4 tunnel addresses. For IPv6 → IPv4, it extracts the embedded IPv4 address from any IPv6-mapped or 6to4 address. All conversions happen instantly in your browser — no data is sent to any server. You can also use our dedicated IPv6 compression page for compression, expansion, and validation.
How to Convert IPv4 to IPv6
Converting an IPv4 address to IPv6 format takes just a few seconds with our free tool. Follow these steps:
1
Enter IPv4 Address
Type any valid IPv4 address into the input field (e.g., 192.168.1.1, 10.0.0.1, or 8.8.8.8).
2
Click Convert
Press the Convert button or hit Enter. The tool instantly calculates both IPv6-mapped and 6to4 formats.
3
Copy Results
Click the copy icon next to any result to copy it to your clipboard for use in configurations or code.
IPv6-Mapped vs 6to4 Tunnel Addresses
Our IPv4 to IPv6 converter outputs two distinct formats. Each serves a different purpose in the IPv4/IPv6 transition:
IPv6-Mapped (RFC 4291)
Format: ::ffff:x.x.x.x
IPv6-mapped addresses embed the original IPv4 address in the last 32 bits of a 128-bit address, preceded by 80 zero bits and 16 one bits (ffff). This is the standard format used in dual-stack operating systems — when an IPv6 socket receives a connection from an IPv4 host, the kernel represents it as an IPv6-mapped address.
Dual-stackActive standardSocket API
6to4 Tunnel (RFC 3056)
Format: 2002:xxxx:xxxx::
6to4 addresses use the 2002::/16 prefix followed by the IPv4 address encoded as two hexadecimal groups. This format was designed for automatic tunneling of IPv6 packets over IPv4 infrastructure. Deprecated by RFC 7526 (2015) due to reliability and security concerns.
TunnelingDeprecatedLegacy
IPv4 to IPv6 Conversion Examples
Here are common IPv4 addresses and their IPv6-mapped and 6to4 tunnel equivalents:
| IPv4 Address | IPv6-Mapped | 6to4 Tunnel | Type |
|---|---|---|---|
| 192.168.1.1 | ::ffff:192.168.1.1 | 2002:c0a8:0101:: | Private network |
| 10.0.0.1 | ::ffff:10.0.0.1 | 2002:a00:1:: | Private (Class A) |
| 8.8.8.8 | ::ffff:8.8.8.8 | 2002:808:808:: | Google DNS |
| 1.1.1.1 | ::ffff:1.1.1.1 | 2002:101:101:: | Cloudflare DNS |
| 172.16.0.1 | ::ffff:172.16.0.1 | 2002:ac10:1:: | Private (Class B) |
| 255.255.255.255 | ::ffff:255.255.255.255 | 2002:ffff:ffff:: | Broadcast |
IPv4 vs IPv6 — Key Differences
Understanding the differences between IPv4 and IPv6 helps explain why address conversion is necessary:
| Feature | IPv4 | IPv6 |
|---|---|---|
| Address Size | 32 bits | 128 bits |
| Address Format | Dotted decimal (192.168.1.1) | Hexadecimal colon (2001:db8::1) |
| Total Addresses | ~4.3 billion (2³²) | ~340 undecillion (2¹²⁸) |
| Header Size | 20-60 bytes (variable) | 40 bytes (fixed) |
| IPsec | Optional | Built-in support |
| Broadcast | Yes | No (uses multicast) |
| NAT Required | Common (address shortage) | Rarely needed |
| Checksum | Header checksum | No header checksum |
How IPv4 to IPv6 Mapping Works
The IPv6-mapped IPv4 address format follows a specific bit layout defined in RFC 4291. Here's how the 128-bit address is constructed:
IPv4: 192.168.1.1
Step 1: Convert each octet to hex: 192 → c0, 168 → a8, 1 → 01, 1 → 01
Step 2: Group into 16-bit pairs: c0a8 and 0101
Step 3: Add the ::ffff: prefix (80 zero bits + 16 one bits):
0000:0000:0000:0000:0000:ffff:c0a8:0101= ::ffff:c0a8:0101 = ::ffff:192.168.1.1For 6to4, the IPv4 hex values follow the 2002:: prefix: 2002:c0a8:0101::. The remaining 80 bits can be used for subnet and interface identifiers.
When Do You Need IPv4 to IPv6 Conversion?
Dual-Stack Server Config
Configure servers that accept both IPv4 and IPv6 connections. The OS uses IPv6-mapped addresses to represent IPv4 clients on IPv6 sockets.
Firewall & ACL Rules
Write firewall rules that handle both IPv4 and IPv6 traffic. Some firewalls require IPv6-mapped format for unified access control lists.
Network Logging & Analysis
Parse and correlate network logs that contain mixed IPv4 and IPv6 addresses. Convert to a common format for consistent analysis.
Application Development
Build applications that work on dual-stack networks. IPv6 socket APIs often represent IPv4 connections using mapped addresses.
Migration Planning
Plan IPv4-to-IPv6 network migrations by mapping existing IPv4 address allocations to their IPv6 equivalents.
DNS & Reverse Lookup
Configure PTR records and reverse DNS zones for IPv6-mapped addresses. Essential for email deliverability on dual-stack mail servers.
IPv6 Transition Mechanisms
IPv4 to IPv6 conversion is part of a broader set of transition mechanisms. Understanding where mapped addresses fit helps you choose the right approach for your network:
Dual-Stack
RecommendedRun IPv4 and IPv6 simultaneously. IPv6-mapped addresses (::ffff:) bridge the protocols at the socket layer. The most widely deployed approach.
NAT64 / DNS64
ActiveTranslates IPv6 traffic to IPv4 for IPv6-only networks accessing IPv4 services. Uses the 64:ff9b::/96 prefix. Common in mobile carrier networks.
464XLAT
ActiveCombines CLAT (customer-side) and PLAT (provider-side) translation. Enables IPv4-only apps to work over IPv6-only networks. Used by Android and iOS.
DS-Lite
ActiveDual-Stack Lite tunnels IPv4 over IPv6 to a carrier-grade NAT. Used by ISPs to conserve IPv4 addresses while running IPv6 natively.
6to4 Tunneling
DeprecatedAutomatic tunneling using 2002::/16 prefix. Deprecated by RFC 7526 due to reliability issues with relay routers and NAT traversal problems.
Teredo
DeprecatedTunneling for hosts behind NAT using 2001:0000::/32 prefix. Largely replaced by native IPv6 and other mechanisms.
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Frequently Asked Questions
How do I convert an IPv4 address to IPv6?
Enter your IPv4 address (e.g., 192.168.1.1) into the converter. The tool instantly generates the IPv6-mapped format (::ffff:192.168.1.1) and the 6to4 tunnel format (2002:c0a8:0101::). The IPv6-mapped format is the most commonly used for dual-stack environments.
What is an IPv6-mapped IPv4 address?
An IPv6-mapped IPv4 address uses the format ::ffff:x.x.x.x as defined in RFC 4291. It embeds the IPv4 address in the last 32 bits of a 128-bit IPv6 address, with the prefix ::ffff: indicating it's a mapped address. This format allows IPv6-only applications to communicate with IPv4 hosts on dual-stack systems.
What is the difference between IPv6-mapped and 6to4 addresses?
IPv6-mapped addresses (::ffff:x.x.x.x) are used for dual-stack communication within a single host or network, allowing IPv6 sockets to handle IPv4 connections. 6to4 addresses (2002:xxxx:xxxx::) were designed for tunneling IPv6 traffic over IPv4 infrastructure. IPv6-mapped is the standard used today, while 6to4 has been deprecated by RFC 7526.
Can every IPv4 address be converted to IPv6?
Yes. Every valid IPv4 address (0.0.0.0 through 255.255.255.255) can be represented in IPv6 format. The conversion is deterministic — each IPv4 address maps to exactly one IPv6-mapped address and one 6to4 tunnel address. However, IPv6 has a vastly larger address space (2^128 vs 2^32), so not every IPv6 address has an IPv4 equivalent.
Is 6to4 tunneling still used?
6to4 tunneling (RFC 3056) has been officially deprecated by RFC 7526 due to reliability and security concerns, including issues with relay routers and NAT traversal. Modern networks use native IPv6 deployment or other transition mechanisms like 464XLAT, NAT64, and DS-Lite. However, understanding 6to4 remains important for legacy system migration and troubleshooting.
What RFC standards govern IPv4 to IPv6 conversion?
IPv6-mapped IPv4 addresses are defined in RFC 4291 (IP Version 6 Addressing Architecture). 6to4 tunnel addresses are defined in RFC 3056 (Connection of IPv6 Domains via IPv4 Clouds). RFC 7526 deprecated 6to4 in 2015. RFC 4038 provides application transition guidelines, and RFC 6052 defines IPv6 addressing for IPv4/IPv6 translators.
How does the IPv6-mapped format work technically?
The IPv6-mapped format places 80 zero bits, followed by 16 one bits (ffff), followed by the 32-bit IPv4 address. For example, 192.168.1.1 becomes ::ffff:192.168.1.1. In full expanded form, this is 0000:0000:0000:0000:0000:ffff:c0a8:0101, where c0a8 = 192.168 and 0101 = 1.1 in hexadecimal.
Why do we need IPv4 to IPv6 conversion?
IPv4 addresses are exhausted (only ~4.3 billion). IPv6 provides ~340 undecillion addresses. During the transition period, networks must handle both protocols. IPv4 to IPv6 conversion enables dual-stack servers, firewall rule configuration, network logging, application development on mixed-protocol networks, and migration planning.
Is my data safe when using this converter?
Yes. This tool runs entirely in your browser using client-side JavaScript. No IP address data is sent to any server. The conversion is performed locally using mathematical operations, making it completely private and instant. There are no API calls, no logging, and no data collection.
What is the difference between IPv4 and IPv6?
IPv4 uses 32-bit addresses (e.g., 192.168.1.1) providing ~4.3 billion addresses. IPv6 uses 128-bit addresses (e.g., 2001:db8::1) providing ~340 undecillion addresses. IPv6 also adds built-in IPsec support, simplified header format, no broadcast (uses multicast), and eliminates the need for NAT in most cases.