Base Converter
Convert numbers between decimal, binary, octal and hexadecimal.
About this tool
The Base Converter transforms a number between the four numeral systems most commonly used in computing: **decimal** (base 10, the everyday system), **binary** (base 2, the famous 0s and 1s of hardware), **octal** (base 8, used for Unix file permissions) and **hexadecimal** (base 16, found in memory addresses, CSS colors and much more).
To convert, click the button for your input base (Decimal, Binary, Octal or Hexadecimal) and type the number. The result in the other three bases appears instantly, each with its standard prefix: `0b` for binary, `0o` for octal and `0x` for hexadecimal. Click any result row to copy that value.
This converter is indispensable day-to-day for systems programmers, embedded electronics engineers and security professionals. Practical examples: understanding Linux file permissions (`chmod 755` = `0b111101101` in binary), converting CSS colors (`#FF5733` to its decimal components), analyzing memory addresses in debuggers, and interpreting register flags in microcontrollers.
All processing is done locally by the browser's JavaScript using `parseInt` and `toString` with radix. There is no server communication.
Frequently asked questions
Is the tool free?
Yes, completely free.
Is data sent to a server?
No. The conversion happens entirely in the browser, with no external communication.
Does it work on mobile?
Yes, in any modern browser for Android and iOS.
What is the largest number supported?
The limit is JavaScript's safe integer: 2^53 - 1 (9,007,199,254,740,991 in decimal). Larger numbers may exhibit precision issues.
Can I convert negative numbers?
The tool works with positive integers. Negative numbers depend on the representation used (two's complement, sign-magnitude) and vary by hardware or language context, which is outside the scope of this general-purpose tool.