Dev Tool

Number Base Converter

Convert numbers between binary, octal, decimal and hexadecimal instantly. Edit any field to update all others.

Binary (Base 2)

Octal (Base 8)

0-7

Decimal (Base 10)

0-9

Hexadecimal (Base 16)

0-9, A-F

BIT VISUALISATION

CUSTOM BASE CONVERTER

Number

From base

To base

Result

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Edit any field

Change any value and all other bases update instantly. No convert button needed.

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Bit visualiser

See the binary representation of any number as individual bits with position labels.

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Custom bases

Convert between any base from 2 to 36 — including base 32, base 58 and others.

Frequently Asked Questions

What are number bases used for in programming?

Binary (base 2) is the fundamental language of computers — all data is stored as 0s and 1s. Hexadecimal (base 16) is used to represent binary data compactly — memory addresses, color codes (#FF5733), byte values. Octal (base 8) is used in Unix file permissions (chmod 755).

How do I convert binary to decimal manually?

Multiply each bit by 2 raised to its position (counting from 0 on the right). 1011 in binary = 1×8 + 0×4 + 1×2 + 1×1 = 8+0+2+1 = 11 in decimal.

What is the maximum number I can convert?

JavaScript handles integers safely up to 2^53 - 1 (9,007,199,254,740,991). For larger numbers the converter uses BigInt internally where supported.