Number Base Converter

Convert numbers between binary, octal, decimal, hexadecimal, and any base (2-36). Supports BigInt for arbitrary precision.

Input base:
Custom:
Additional output base:(2-36)
Binary0b1111 1111
Octal0o377
Decimal255
Hexadecimal0xff
Base 327v

Number Info

Decimal Value

255

Bit Length

8

Byte Size

1

Hex Length

2

What is Number Base?

A number base (radix) defines how many unique digits are used to represent numbers. Base 10 uses 0-9, base 2 (binary) uses 0-1, base 16 (hexadecimal) uses 0-9 and A-F. Computers use binary internally, while hex is a compact way to represent binary data.

BigInt Support

This converter uses JavaScript BigInt for arbitrary precision. You can convert numbers of any size without losing precision -- even numbers larger than 2^53, which is the limit of regular JavaScript numbers.

How to Convert Number Bases Online

  1. 1. Select the input base by clicking BIN, OCT, DEC, HEX, or enter a custom base (2-36).
  2. 2. Type or paste your number in the input field. Common prefixes like 0x, 0b, 0o are auto-stripped.
  3. 3. View real-time conversions in binary, octal, decimal, hexadecimal, and your custom base.
  4. 4. Toggle prefixes, digit grouping, or uppercase for your preferred format.
  5. 5. Hover over any result and click Copy to copy the value to your clipboard.

Frequently Asked Questions

What number bases are supported?

This tool supports all bases from 2 to 36. The four most common bases (binary/2, octal/8, decimal/10, hexadecimal/16) have preset buttons. You can also enter any custom base between 2 and 36 for both input and output.

Can I convert very large numbers?

Yes! This converter uses JavaScript BigInt internally, so there is no upper limit on the number size. You can safely convert numbers with hundreds of digits without losing any precision.

What do the prefixes 0b, 0o, and 0x mean?

0b indicates a binary number (base 2), 0o indicates an octal number (base 8), and 0x indicates a hexadecimal number (base 16). These are standard prefixes used in most programming languages including JavaScript, Python, C, and Go.

What is digit grouping and why is it useful?

Digit grouping adds spaces between groups of digits for readability. Binary is grouped by 4 bits (nibbles), octal by 3 digits, decimal by 3 digits (thousands), and hex by 2 digits (bytes). This makes it much easier to read long numbers at a glance.