Binary & Low-Level Encoding Guide

Number Systems

Computers use different number bases to represent data. Here are the ones you'll encounter most:

• Binary (base 2): the foundation. Only 0 and 1. How computers actually store everything.
• Octal (base 8): used in Unix file permissions (e.g., chmod 755).
• Decimal (base 10): what humans use daily.
• Hexadecimal (base 16): compact binary representation. Used for colors (#FF0000), memory addresses, and byte values.

Conversion Table

Decimal  Binary     Octal  Hex
0        00000000   000    00
10       00001010   012    0A
42       00101010   052    2A
127      01111111   177    7F
255      11111111   377    FF

Hexadecimal in Practice

Hex is everywhere in web development:

// CSS colors
color: #3B82F6;     // Each pair = one byte (R, G, B)

// JavaScript
0xFF === 255        // Hex literal
(42).toString(16)   // "2a", decimal to hex
parseInt("2a", 16)  // 42 , hex to decimal

// Viewing raw bytes
Buffer.from("Hi").toString("hex") // "4869"

ROT13

ROT13 shifts each letter 13 positions in the alphabet. It's its own inverse, apply it twice and you get the original text. It's not encryption, just simple obfuscation used for spoilers and puzzles.

Hello → Uryyb
Uryyb → Hello  (applying ROT13 again reverses it)

A B C D ... M N O P ... Z
↓               ↓
N O P Q ... Z A B C ... M

Base32 Encoding

Base32 uses A-Z and 2-7 (no confusing characters like 0/O or 1/l). It's used in TOTP authenticator apps, onion addresses, and case-insensitive contexts where Base64 won't work.

Try our Binary Converter, Hex Encoder, or ROT13 Encoder to experiment with encoding.