Number Base Converter
Convert numbers between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). Type in any field and all others update instantly — supports large integers.
Number Base Converter
Type a number in any base — all others update instantly.
Binary
Base 2 0b…
Octal
Base 8 0o…
Decimal
Base 10
Hexadecimal
Base 16 0x…
What is a number base converter?
Decimal (base 10) is everyday counting. Binary (base 2) is how computers store data. Octal (base 8) appears in Unix file permissions. Hexadecimal (base 16) compactly represents bytes and is used in color codes, memory addresses, and encoding schemes.
Reading hex color values
A hex color like #1A2B3C is three pairs: 1A = red (26), 2B = green (43), 3C = blue (60). Each pair is one byte (0–255 in decimal).
BigInt precision
This tool uses JavaScript's BigInt to handle arbitrarily large numbers without precision loss — unlike standard Number, which loses accuracy beyond 53-bit integers.
How to use
- Enter a number in any of the four fields — binary, octal, decimal, or hexadecimal.
- The equivalent values in all other bases appear instantly.
- Copy any result with the "Copy" button next to each field.
Frequently Asked Questions
- What is binary (base 2)?
- Binary is a base-2 number system using only digits 0 and 1. It is the fundamental language of computers — every number, character, and instruction in a computer is ultimately represented as binary bits.
- What is hexadecimal (base 16)?
- Hexadecimal (hex) is a base-16 number system using digits 0-9 and letters A-F. It is widely used in programming, color codes (#FF5733), memory addresses, and binary data because each hex digit represents exactly 4 binary bits.
- How do I convert decimal to binary?
- To convert decimal to binary, repeatedly divide the number by 2 and record the remainders. Reading remainders from bottom to top gives the binary representation. For example, 255 in decimal equals 11111111 in binary.
- What is octal (base 8) used for?
- Octal is a base-8 number system (digits 0-7). It is used in Unix/Linux file permissions (e.g. chmod 755) and some legacy computing contexts. Each octal digit represents exactly 3 binary bits.