Number Converter

Free Online Number Base Converter

Convert any number between Decimal, Hexadecimal, Binary, and Octal instantly — and convert text strings to ASCII, Hex, and Binary codes.

What Are Number Bases?

A number base (or radix) defines how many unique digits a number system uses:

• Decimal (Base 10) — digits 0–9. The everyday number system we use.
• Hexadecimal (Base 16) — digits 0–9 and A–F. Used in programming, HTML colors, memory addresses, and byte representation.
• Binary (Base 2) — only 0 and 1. How computers store and process all data at the hardware level.
• Octal (Base 8) — digits 0–7. Used in Unix file permissions and some legacy systems.

Common Conversions at a Glance

• Decimal 255 = Hex FF = Binary 11111111 = Octal 377
• Decimal 65 = Hex 41 = Binary 1000001 = ASCII 'A'
• Decimal 0 = Hex 00 = Binary 0 = Octal 0
• Decimal 16 = Hex 10 = Binary 10000 = Octal 20

ASCII / Text Encoding Explained

ASCII (American Standard Code for Information Interchange) assigns a unique decimal number to each character:

• Space = 32, '!' = 33, '0'–'9' = 48–57
• 'A'–'Z' = 65–90, 'a'–'z' = 97–122
• The letter 'H' = decimal 72 = hex 0x48 = binary 01001000

This tool converts entire text strings to their ASCII code sequences in decimal, hex, or binary — and decodes them back to text.

Common Use Cases

• Converting HTML color codes (e.g. #FF5733) to RGB decimal values
• Reading binary/hex values from memory dumps or network packet captures
• Understanding Unix file permissions (e.g. chmod 755 = octal 111 101 101)
• Encoding/decoding CTF challenge data in hex or binary
• Verifying ASCII character codes when debugging text encoding issues
• Converting IP addresses between decimal and hex notation

How to Use This Tool

1. Number Converter: Type any number in any field — all other bases update instantly.
2. Text Encoder: Type or paste text in the left panel, choose a format (ASCII / Hex / Binary), see the codes on the right.
3. Decoder: Paste codes in the lower-left, choose the format, and see the decoded text on the right.
4. Use Copy buttons to grab the result for use anywhere.