IP to Integer

Features

• Both directions, with automatic detection and a manual override
• Unsigned and signed on separate rows — the direct answer to “why is it negative in my database”
• Dotted decimal, hexadecimal and optional binary in one pass
• For IPv4-mapped IPv6 (`::ffff:192.168.1.1`), the embedded IPv4 is shown too
• Reverse DNS name (`1.1.168.192.in-addr.arpa`)
• IPv6 uses exact 128-bit integers; beyond 128 bits it errors instead of wrapping
• Negative input errors instead of guessing two’s complement
• Everything is computed on your device

How to use

1. Paste an IP address or an integer into the left pane
2. The direction is detected automatically; override it if you like
3. Results appear immediately, each row copyable on its own

FAQ

Why is the IP coming out of my database negative?

Because that column is a signed integer. A MySQL `INT` is signed 32-bit, so its range is roughly ±2.1 billion; `192.168.1.1` is 3232235777 unsigned, which is past the positive limit and therefore displays as `-1062731519` in two’s complement. The data is fine — it is the same bits read the other way. You can fix it by changing the column to `INT UNSIGNED`, or by casting when you read it. Both readings are shown side by side here so you can match them up at a glance.

What is the point of storing IPs as integers?

Two things: space (4 bytes instead of 15, and the index shrinks with it) and range queries. The second matters more. With strings, “find every record inside 192.168.0.0/16” means `LIKE '192.168.%'` — which also matches things like `192.168.0.1.example.com` and cannot use the index. Stored as an integer it is just `WHERE ip BETWEEN 3232235520 AND 3232301055`, and the index works.

Why can’t `-1` be converted? It is obviously `255.255.255.255`.

Under your storage scheme it is — but this tool does not know which scheme you use. The same `-1` reads as `255.255.255.255` under signed 32-bit, as `18446744073709551615` under unsigned 64-bit, and as yet another number under arbitrary precision. Guessing wrong about an IP can mean a wrong firewall rule or a record you did not intend to allow. So this errors instead, and shows both the unsigned and signed readings — one look at your schema tells you which applies.