Convert numbers between binary, octal, decimal, and hexadecimal instantly — all four bases update together as you type.
Binary is a base-2 system using only 0 and 1. It's the fundamental number system used internally by all digital computers.
Hex (base-16) compactly represents binary data, since each hex digit maps exactly to 4 binary bits — common for memory addresses, color codes, and byte values.
Octal (base-8) was historically common in early computing and is still used for Unix file permissions, where each digit maps to 3 binary bits.
This tool is designed for non-negative integer conversions, which covers the vast majority of everyday base conversion needs.
This tool converts a number between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16) simultaneously — type a value into any field, and the other three update instantly to show the equivalent value in that base.
Binary is the native language of computer hardware, but raw binary numbers get unwieldy very quickly — a single byte (8 bits) written in binary is 8 characters long, but the same value in hexadecimal is only 2 characters. This is exactly why hex and octal exist as "human-friendly" shorthand for binary: because their bases are powers of 2 (16 = 2⁴, 8 = 2³), converting between them and binary is mechanically simple — you can convert hex to binary or binary to hex digit-by-digit without doing full decimal arithmetic, which isn't true for decimal.
All conversions happen directly in your browser using JavaScript's built-in number parsing — nothing is sent to a server.