Free Number Base Converter — Binary, Hex & Octal Online
Convert between binary, octal, decimal, hexadecimal, and any base from 2 to 36 instantly.
| Base | Value |
|---|
How it works
Enter your number
Type the number you want to convert in the input field.
Set source base
Select or type the base of your input number (2–36).
View results
Binary, octal, decimal, and hex equivalents appear instantly.
Copy any result
Click any result row to copy that value to your clipboard.
Common use cases
Programming & debugging
Convert hex memory addresses, binary flags, and decimal values when working with low-level code.
Computer science study
Practice number system conversions for exams, assignments, and understanding CPU operations.
Colour code conversion
Convert hexadecimal colour codes (#FF5733) to decimal RGB values and back.
Network & bitmasking
Convert IP addresses, subnet masks, and port numbers between binary and decimal.
Frequently asked questions
What bases are supported?
All bases from 2 (binary) to 36. Common ones are 2 (binary), 8 (octal), 10 (decimal), and 16 (hexadecimal).
Why does hexadecimal use letters?
Hex needs 16 symbols but digits only go to 9, so letters A–F represent 10–15. This tool outputs uppercase hex (A–F).
Can I convert negative numbers?
Enter a minus sign before the number for negative values. The converter handles signed integers.
Is this converter free?
Yes — completely free, no account required. Works entirely in your browser.
What is 255 in hexadecimal?
255 in decimal is FF in hexadecimal, 11111111 in binary, and 377 in octal.
Is any data sent to a server?
No — all conversions use JavaScript's built-in parseInt() and toString() in your browser.