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Number Base Converter — DEC/HEX/BIN/OCT/ASCII

Convert between bases 2-36 + ASCII codes. BigInt support for huge numbers, auto-strips 0x/0b/0o prefixes. Useful for bitwise debugging, memory dumps, CS101.

All tools

Enter value

From base

Sample values:

Outputs

Binary (Base 2) —

Octal (Base 8) —

Decimal (Base 10) —

Hexadecimal (Base 16) —

Base 36 —

ASCII / Text ↔ Number

Text

ASCII codes

Binary

Hex

Convert between bases 2-36 + ASCII codes. Supports negative and large numbers (BigInt). Useful for bitwise debugging, memory dumps, and CS101.

Common bases

Base 2 (Binary): 0, 1 — the computer's native unit. 0b1010 = 10.
Base 8 (Octal): 0-7. Rare today — mostly Unix permissions (chmod 755).
Base 10 (Decimal): 0-9. The default everywhere.
Base 16 (Hexadecimal): 0-9, A-F. Used for colors (#FF0000), MAC addresses, memory addresses. 0xFF = 255.
Base 36: 0-9, A-Z. Used for short IDs (e.g. shortened YouTube IDs).

When you need base conversion

Bitwise debugging: x & 0xFF = mask the last 8 bits — convert 0xFF to binary to see why.
Memory dumps: hex addresses like 0x7FFE_5F30 — convert to decimal to compute offsets.
CSS colors: #C8102E = RGB(200, 16, 46).
Linux permissions: chmod 755 = octal 111 101 101 = rwxr-xr-x.
Encoding: convert text to ASCII codes to debug encoding issues.