Whole numbers only (no decimals). Handles arbitrarily large values.
Online Number Base Converter
Convert a number between any two bases from 2 to 36 — binary, octal, decimal, and hexadecimal are common presets, but any base in that range works. Useful for reading memory dumps and bit flags, converting color codes, or just checking what a hex literal actually equals in decimal. Handles arbitrarily large whole numbers via BigInt. It helps developers inspect protocol values and convert numbers between binary, octal, decimal, hexadecimal, and other bases.
What is a number base (radix)?
A number's base — also called its radix — determines how many unique digits are used to represent values and what each digit position is worth. Decimal (base 10) is what people use day to day; binary (base 2) is how computers represent everything at the hardware level; hexadecimal (base 16) is a common shorthand for binary data because each hex digit maps to exactly 4 bits. This tool converts a value between any two bases from 2 to 36.
How to convert a number between bases
Enter a value in the input box, choose its current base under From base and the base you want under To base, then click Convert. Use the swap button to instantly reverse direction, or pick any base from 2 to 36 under "All bases" if you need something beyond the common presets.
Common use cases
- Converting a hex literal from source code into decimal to understand its actual value
- Reading raw memory dumps or register values shown in hexadecimal or binary
- Decoding bit flags, where each binary digit represents an on/off setting
- Converting color codes between hex (e.g. #FF5733) and decimal RGB components
Conversion is handled with BigInt internally, so arbitrarily large whole numbers convert accurately without losing precision the way JavaScript's regular number type would beyond 2^53.
How to use Base Converter for related tasks
Enter a valid integer, choose the source and target bases, and check negative values or digits outside the selected base before trusting the result.
Related tools: Byte Parser, Number / Byte Formatter.
Frequently asked questions
What bases does this converter support?
Any base from 2 to 36 — not just the common presets (binary, octal, decimal, hexadecimal). Base 36 uses digits 0-9 followed by letters a-z, the maximum range JavaScript's built-in number formatting supports.
Can I convert negative numbers?
Yes, using sign-and-magnitude — a leading minus sign is preserved through the conversion. Two's-complement negative representation isn't supported, since that requires a fixed bit width that doesn't have a well-defined meaning across arbitrary bases.
Does this handle numbers too large for a normal JavaScript number?
Yes — conversion uses BigInt internally, so arbitrarily large whole numbers convert correctly instead of losing precision the way JavaScript's regular Number type would beyond 2^53.
Can I convert decimal fractions, like 3.14?
No — this tool handles whole numbers (integers) only. Fractional values don't convert cleanly across arbitrary bases the way integers do, so fractional input isn't supported.
How do I convert binary to hex?
Enter the binary value, select base 2 as the source and base 16 as the target; invalid digits are rejected rather than silently reinterpreted.