Convert numbers between binary, octal, decimal, hexadecimal, and any base from 2 to 36.
This free online tool converts numbers between different bases (radixes) instantly in your browser. It supports binary (base 2), octal (base 8), decimal (base 10), hexadecimal (base 16), and any custom base from 2 to 36.
| Base | Name | Digits | Used For |
|---|---|---|---|
| 2 | Binary | 0-1 | CPU operations, bitwise math, networking masks |
| 8 | Octal | 0-7 | Unix file permissions (chmod 755) |
| 10 | Decimal | 0-9 | Everyday numbers, math, counting |
| 16 | Hexadecimal | 0-9, A-F | Colors (#FF5733), memory addresses, byte values |
| 36 | Base36 | 0-9, A-Z | Short URLs, compact IDs |
Hexadecimal (base 16) is popular because each hex digit maps exactly to 4 binary bits. This makes it easy to represent byte values (00-FF) and memory addresses compactly. For example, the binary value 11111111 is simply FF in hex — much easier to read and remember.
The bit visualization shows the binary representation split into 8-bit groups (bytes). This makes it easy to see individual byte values, which is useful for networking, encoding, and low-level programming.
Binary uses only 0 and 1. Each position represents a power of 2 from right to left: 1, 2, 4, 8, 16, 32, 64, 128... For example, binary 1010 = 8 + 0 + 2 + 0 = 10 in decimal.