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IP Address Converter

Switch an IP address between dotted, integer, hex, octal, binary and IPv6 forms, and get its reverse DNS name.

About IP Address Converter

An IP address converter helps when an address turns up in a form you can't read at a glance, like a 32-bit integer such as 3232235777 in a database column, a hex value in a packet dump, ::ffff:203.0.113.5 in an application log, or a long IPv6 address you need to compare with its short form. Enter the address in any of these forms and the converter gives you the others.

IPv4 is shown as dotted decimal, a decimal integer, hexadecimal, octal and binary, and as an IPv4-mapped IPv6 address. IPv6 is written out in full, with every group of zeros, and compressed with the double colon. Both also get their reverse DNS name under in-addr.arpa or ip6.arpa, which is the name a PTR record lives on. Once you know the address, IP WHOIS Lookup tells you who owns it. Everything runs in your browser, so nothing is uploaded, there's no limit, and it works offline once the page has loaded.

How to use IP Address Converter

  1. 1
    Enter an address

    Type or paste an IPv4 address in any supported form, or an IPv6 address.

  2. 2
    Read every form

    See dotted decimal, integer, hex, octal, binary, the IPv6 forms and the reverse DNS name.

  3. 3
    Copy what you need

    Take the form your database, firewall or DNS zone expects.

Why use Cubfile for this

  • Six IPv4 forms

    Dotted decimal, decimal integer, hex, octal, binary and IPv4-mapped IPv6.

  • Full and short IPv6

    Expand :: into every missing group, or compress the zeros again.

  • Reverse DNS names

    The in-addr.arpa or ip6.arpa name to use for PTR records.

  • Private and offline

    Runs in your browser with nothing uploaded and no limit.

FAQ

IP Address Converter: questions and answers

How do I convert an IP address to a decimal number?
Each of the four parts is one byte, so the number is a × 16,777,216 + b × 65,536 + c × 256 + d. 192.168.1.1 becomes 3232235777, the same value MySQL's INET_ATON returns.
Why does my log show ::ffff in front of an IPv4 address?
That's an IPv4-mapped IPv6 address. Servers listening on an IPv6 socket often record IPv4 visitors this way, and the part after ::ffff is the ordinary IPv4 address.
What is the reverse DNS name of an IP address?
The address written backwards under a special domain, so 192.0.2.10 becomes 10.2.0.192.in-addr.arpa. IPv6 uses every hex digit in reverse under ip6.arpa. PTR records are created on these names. To see the PTR record published on that name, enter the IP in DNS Lookup.
How do I expand a shortened IPv6 address?
Enter it here and read the full form, where :: is replaced by the missing groups of zeros and every group has four digits. For a whole IPv6 prefix, the IP Subnet Calculator gives the network and address range.
Is anything sent to a server?
No. Conversion happens in your browser, is free and unlimited, and works offline after the page loads.
Share IP Address Converter with a friendIt runs in any browser, and they can try it without signing up.

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