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Decimal ↔ Hexadecimal Converter

Free online decimal to hex and hex to decimal converter. Convert numbers between base-10 and base-16 instantly.

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Tip: Type in either field — the other updates automatically. Hex output is uppercase.
💡 Definition

Hexadecimal System

  • Hexadecimal (base-16) uses digits 0-9 and letters A-F.
  • It is widely used in computing because each hex digit represents exactly 4 bits, making it a compact way to express binary data.
  • Colors, memory addresses, and MAC addresses all use hex.
📖 How to use

Step by Step

  • Enter a decimal number on the left
  • The hex equivalent appears instantly on the right
  • Or enter a hex value to get decimal
  • Use 0-9 and A-F for hex input
🎯 Use cases

When to use

  • CSS color codes (#FF5733)
  • Memory addresses and debugging
  • MAC address formatting
  • Assembly language programming

Frequently Asked Questions

Why is hex used in computing?
Each hex digit maps to exactly 4 binary bits. So a byte (8 bits) is always 2 hex digits, making hex a compact, readable shorthand for binary data.
What does 0x mean before a hex number?
The "0x" prefix is a convention in programming (C, JavaScript, Python) to indicate that the following number is in hexadecimal format. For example, 0xFF = 255 in decimal.