Number Base Converter
Type a number in any base — decimal, binary, hex, or octal — and watch all four update live.
How to use the number base converter
- Type a number into any of the four fields.
- The other three bases update instantly.
- Invalid digits for a base show a clear error instead of silently failing.
Number base tips
Programmers live in hexadecimal because each hex digit maps neatly to four bits — that is why memory addresses, color codes, and UUIDs are all hex. Binary is the machine's native tongue, useful for bitmask flags and subnet math. Octal survives mostly in Unix file permissions (chmod 755) and a few legacy corners. When converting by hand, remember the anchor points: 255 is FF in hex and 11111111 in binary, 16 is 10 in hex, and 8 is 10 in octal. This tool handles values up to JavaScript's safe integer range; beyond that, floating-point rounding creeps in, so keep cryptographic-size numbers to dedicated big-integer tools.
Frequently asked questions
What bases are supported?
Decimal (10), binary (2), octal (8), and hexadecimal (16) — the four bases developers actually use.
Why is there a size limit?
JavaScript numbers are precise only up to 2^53 - 1. Larger values may round, so this tool caps there.
Can it handle negative numbers?
Yes — enter a leading minus sign in any field and all bases show the negative value.
What is the 0x prefix?
A common notation meaning "hexadecimal follows." This tool accepts plain digits; add 0x yourself when pasting into code.