Binary is a base-2 numbering system using only the digits 0 and 1. All data in computers is ultimately stored and processed as binary.

Does it accept the 0b prefix?

Yes. Both '1010' and '0b1010' are accepted as binary inputs.

Is there a maximum number of bits?

The converter uses arbitrary-precision integer arithmetic (BigInt), so there is no fixed maximum: even values far beyond 53 bits convert exactly without losing precision.

Can I paste bits with spaces, like 1010 1100?

Paste the bits without separators. The converter accepts only 0 and 1 after an optional 0b prefix, so 10101100 converts to 172 while 1010 1100 shows a validation message.

Binary to decimal converter

Enter a binary number (base 2, using only 0s and 1s) to instantly see its decimal, hexadecimal, and octal equivalents.

BIN input (base 2)

BIN–

OCT–

DEC–

HEX–

INPUT BASE

All bases shown simultaneously.

Runs entirely in your browser

Worked example

Add the place value of every 1 bit: 101101 = 32 + 8 + 4 + 1 = 45, which is 2D in hex and 55 in octal.

How it works

The input is checked digit by digit and turned into a JavaScript BigInt, then written out with BigInt.prototype.toString(base), so large values stay exact. All four bases are computed simultaneously from the same input value, so you can see binary, octal, decimal, and hex at a glance.

Processing runs in your browser

All conversion runs in your browser tab. Our servers are not involved at any point.

Related operations

For converting between data sizes like KB and MB, try the byte converter. To compute MD5 or SHA hashes from values, use the hash generator. For working with file permission bits, see the chmod calculator.

Frequently asked questions

What is binary?: Binary is a base-2 numbering system using only the digits 0 and 1. All data in computers is ultimately stored and processed as binary.
Does it accept the 0b prefix?: Yes. Both '1010' and '0b1010' are accepted as binary inputs.
Is there a maximum number of bits?: The converter uses arbitrary-precision integer arithmetic (BigInt), so there is no fixed maximum: even values far beyond 53 bits convert exactly without losing precision.
Can I paste bits with spaces, like 1010 1100?: Paste the bits without separators. The converter accepts only 0 and 1 after an optional 0b prefix, so 10101100 converts to 172 while 1010 1100 shows a validation message.

Last reviewed September 30, 2026

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