🔢 Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal instantly. Supports large numbers and shows all bases simultaneously. Free online number base converter.
0-9
0-1
0-9 A-F
0-7
How to Use
1
Enter any number
Type a number into any of the four fields: Decimal, Binary, Hexadecimal, or Octal.
2
All bases update instantly
The other three fields automatically update with the equivalent value in real-time.
3
Copy any format
Click the Copy button next to any field to copy that representation to your clipboard.
Frequently Asked Questions
What are the different number bases?
Decimal (base 10) uses digits 0-9 and is the everyday number system. Binary (base 2) uses only 0 and 1, used by computers. Octal (base 8) uses digits 0-7. Hexadecimal (base 16) uses 0-9 and A-F, widely used in programming for memory addresses and colors.
What does 0x prefix mean in hexadecimal?
0x is the standard prefix for hexadecimal numbers in most programming languages (C, JavaScript, Python). So 0xFF = 255 in decimal. Similarly, 0b prefix is used for binary (0b11111111 = 255).
How do I convert a hex color code to RGB?
A hex color like #FF5733 has three pairs: FF (red), 57 (green), 33 (blue). Convert each pair from hex to decimal: FF=255, 57=87, 33=51. Result: rgb(255, 87, 51). Our Color Picker tool does this automatically.
What is the largest number supported?
The tool handles integers up to JavaScript's Number.MAX_SAFE_INTEGER (2^53 - 1 = 9,007,199,254,740,991). For very large numbers (64-bit+), precision may be limited.
Is any data sent to a server?
No. All conversions are calculated in your browser using JavaScript's built-in parseInt() and toString() functions. Nothing is sent anywhere.
Guide : Convertisseur de Bases Numériques
Qu'est-ce que c'est ?
Le Convertisseur de Bases Numériques convertit les nombres entre binaire (base 2), octal (base 8), décimal (base 10) et hexadécimal (base 16) instantanément.
Indispensable pour la programmation bas niveau, les masques réseau, la manipulation des couleurs et le débogage des systèmes embarqués.
Comment utiliser
- Entrez votre nombre dans la base source.
- Sélectionnez la base source (bin/oct/dec/hex).
- Toutes les conversions s'affichent simultanément.
- Copiez la valeur dans le format souhaité.
Conseils professionnels
- Les couleurs CSS hexadécimales sont en base 16 :
#FF0000= rgb(255,0,0). - En JavaScript,
parseInt('FF', 16)etNumber('0xFF')décodent l'hex en décimal.