Number Base Converter
How to Use
Select the input number base, then type your number. The tool instantly converts it to all four bases (binary, octal, decimal, hexadecimal). Click the copy button next to any result to copy it to your clipboard.
Number Base Systems
A number base (or radix) defines how many unique digits are used to represent numbers. Binary (base 2) uses 0-1 and is fundamental to computing. Octal (base 8) uses 0-7. Decimal (base 10) uses 0-9 and is the standard human system. Hexadecimal (base 16) uses 0-9 and A-F, commonly used for colors, memory addresses, and byte values.
Use Cases
- Reading memory dumps — convert hex-displayed memory contents to decimal or binary to understand values
- Color code conversion — translate CSS hex colors (#FF5733) to decimal RGB values and vice versa
- File permission calculations — expand Unix octal permissions (755, 644) to binary to see individual permission bits
- Bitwise debugging — display flags and bitmasks in binary to visually inspect the state of each bit
Mental Conversion Tricks
Each hex digit maps to exactly 4 binary digits (bits). For example, 0xF = 1111 and 0xA = 1010. Once you memorize these mappings, you can convert between hex and binary one digit at a time. Similarly, each octal digit corresponds to exactly 3 binary digits (e.g., 7 = 111, 5 = 101). For decimal-to-hex conversion, repeatedly divide by 16 and note the remainders. Memorizing commonly used values — 0xFF = 255, 0x100 = 256, 0x400 = 1024 — speeds up code reading significantly.
Privacy
All conversions happen entirely in your browser using JavaScript's BigInt for arbitrary precision. No data is sent to a server, stored, or logged.
FAQ
What is the difference between binary, octal, decimal, and hexadecimal?
The difference is how many digits (the radix) each position uses: binary uses 0-1, octal 0-7, decimal 0-9, and hexadecimal 0-9 plus A-F. The same value looks different and has a different digit count across bases, but the underlying number is identical.
Are the numbers I enter sent to a server?
No. Every conversion runs in your browser using JavaScript's BigInt, and your input is never sent to, stored on, or logged by a server. You can safely convert sensitive values.
Can it convert very large numbers?
Yes. Because it uses JavaScript's BigInt, it converts numbers far beyond the usual integer limit with full accuracy. There is no rounding error from overflow.
Do I need to type A-F in uppercase for hex, and can I use decimals or negatives?
Hex digits A-F can be entered in either uppercase or lowercase. The tool handles integer base conversion only, so fractional values and negative numbers are not supported. If the input contains a character invalid for the selected base, an error is shown.
How do I use it to convert a hex color code to decimal RGB?
Split the color into two-digit pairs (RR, GG, BB), set the input base to hexadecimal, and enter each pair to get its decimal value. For `FF5733`, for example, `FF` → 255, `57` → 87, and `33` → 51.