Number Base Converter
Convert a number between bases by typing it in whichever box you have it in: binary, octal, decimal, hex, or any base up to 36. Every other box updates as you type.
How to convert between number bases
- 1Type your number in the box for its base.
- 2Read it in every other base at once.
- 3Copy any of them, or group digits to make long numbers readable.
Any size, any base
Numbers of any length convert exactly, with no rounding, and negative numbers work too. Binary, octal, decimal and hexadecimal each get a box, and another box takes any base from 2 to 36.
Prefixes and separators
Prefixes like 0b, 0o and 0x are accepted in their own boxes, and spaces and underscores between digit groups are ignored, so 1111_0000 and 0xFF both work.
Bits and bytes
Under the boxes you see how many bits and bytes the number needs, which helps when picking an integer type.
Frequently asked questions
- Is my data uploaded?
- No. The conversion runs in your browser and nothing is sent anywhere.
- Can it convert fractions?
- No, only whole numbers. Fractions often have no exact form in other bases.
- What digits does base 36 use?
- 0–9 and then A–Z, so Z is 35. Base 36 is handy for short IDs.