Number Base Converter
Convert numbers between binary, octal, decimal, hexadecimal and any base from 2 to 36 — with fractions, negative numbers, two’s complement, a clickable bit grid and the working shown step by step.
- Your data never leaves your device
- 100% free
- No sign-up
- Works offline after first load
How to use the number base converter
- Type or paste the number (prefixes, spaces and underscores are fine).
- Pick the bases — the result, the other bases, the bits and the working appear instantly.
- Swap, choose signed / bit width / grouping, convert a list, or copy and share.
About Number Base
Convert numbers between binary, octal, decimal, hexadecimal and any base from 2 to 36. The answer comes with the working shown step by step, so you can check it or learn the method.
The same number is shown in every common base, as big- and little-endian bytes and as bits you can click to flip. Choose signed two’s complement and a bit width, group digits, pad with zeros, add 0x / 0b prefixes, convert a whole list at once or inspect how a float is stored in IEEE-754.
Good for
- Programming, debugging and reading memory dumps
- Computer science and digital electronics homework
- Networking masks, colours, permissions and flags
Tip: Click the bits in the grid to flip them — the number updates in every base, which is a quick way to build masks and flags.
Frequently asked questions
Which bases are supported?
Every base from 2 to 36 — binary, ternary, octal, decimal, duodecimal, hexadecimal, base 32, base 36 and all in between. Letters a–z are the digits after 9.
Does it detect the base automatically?
Yes — with “Detect”, 0x… is read as hex, 0b… as binary, 0o… as octal and #… as hex; plain digits are decimal.
Can it handle very large numbers?
Yes. It uses arbitrary-precision integers, so numbers with hundreds or thousands of digits convert exactly.
Can it convert fractions?
Yes — 0.1 in binary is shown as 0.0(0011) with the repeating part marked, and you can choose how many fraction digits to show.
What is two’s complement?
The way computers store negative integers: invert the bits and add 1. Pick “Signed” and a bit width to read or write negative binary and hex numbers.
Can it show how a float is stored?
Yes — the IEEE-754 tab shows the sign, exponent and mantissa bits of a float32 or float64 value, its hex, and the exact value the computer stores.