🔢 Number Tools
Number Base Converter
Convert numbers between decimal, binary, hexadecimal and octal. All four bases shown simultaneously with a reference table.
Base Converter
Enter a number in any base below — all others update instantly.
Digits: 0–9
Digits: 0–1
Digits: 0–9, A–F
Digits: 0–7
Quick reference
| Dec | Bin | Hex | Oct |
|---|
How to use the Base Converter
1
Enter any base
Type a number in any of the four boxes and the other three update instantly. Decimal is the normal counting system (0–9). Binary uses only 0s and 1s — it is how computers store data. Hexadecimal uses digits 0–9 and letters A–F — it is widely used in color codes, memory addresses and programming.
2
Common uses
Hex color codes in CSS are hexadecimal — #FF6600 is red 255, green 102, blue 0 in decimal. Binary is used in networking (IP addresses) and computing. Octal was historically used in computing but is now mainly seen in Unix file permissions (e.g. chmod 755). The quick reference table shows all four bases side by side.