How to use the Number Base Converter
Type a number in any base — all other representations update instantly. Supports Binary (base 2), Octal (base 8), Decimal (base 10), Hexadecimal (base 16), and Base64.
What is it?
Number base conversion is fundamental in computing. Binary (base 2) is how computers store data. Hexadecimal (base 16) compactly represents binary (each hex digit = 4 bits), commonly used for memory addresses, color codes, and byte values. Octal (base 8) appears in Unix file permissions. Base64 encodes binary data as ASCII text for safe transport.
Benefits
Read values instantly in the format you need
Timestamps as human-readable dates, hex colors as HSL or RGB, identifier names in any case convention — the exact representation you need, without conversion arithmetic.
Eliminate manual conversion errors
Epoch-to-date math, hex-to-RGB lookup, and case-by-case string replacement are all error-prone by hand. Automated conversion is exact every time.
Consistent format across your codebase or design system
Standard case conventions for variable names and a single color format for design tokens prevent subtle inconsistencies that accumulate across a project over time.
Output that works in any tool directly
Colors formatted for CSS, Figma, and Tailwind; timestamps ready for database queries; identifiers in the convention of your language or framework — paste and use.
Frequently asked questions
Why do hex values use 0–9 and A–F?
Hexadecimal needs 16 symbols. After 9, it uses A (10), B (11), C (12), D (13), E (14), F (15). So FF = 255 in decimal = 11111111 in binary.
What's 0x prefix in hex?
0x is a conventional prefix indicating hexadecimal notation in code (C, JavaScript, Python). 0b means binary, 0o means octal. The tool shows values without the prefix for clarity.