Numbers can be written in different bases — binary (2), octal (8), decimal (10) and hexadecimal (16). This tool converts a number between all of them at once, instantly and locally.
How to use it
- Type a number into any base field.
- All other bases update instantly.
- Copy whichever representation you need.
About Number Base Converter
Base conversion is routine in low-level and systems work: memory addresses and color codes are hex, permission bits and flags are binary or octal, and humans read decimal. Converting in your head is slow and mistake-prone past small values. This tool keeps every base in sync from one input, so you can read a value in hex and instantly see its binary or decimal form. All math runs in your browser.
FAQ
Why is hexadecimal used so much?
Because one hex digit maps to exactly four binary bits, hex is a compact, readable way to write binary data like colors and memory.
What is octal used for?
Most commonly Unix file permissions, where each digit encodes read/write/execute bits.
Why do programmers use hexadecimal and binary?
Binary reflects how computers actually store data, while hexadecimal is a compact way to write binary (one hex digit equals four bits). They appear in colour codes, memory addresses, bitmasks and low-level programming.