Understanding Hexadecimal
Hexadecimal (base-16) is a compact way to represent binary data. Each hex digit represents 4 bits, so two hex digits make one byte. Programmers use hex extensively because it's more readable than binary while maintaining a direct relationship with byte values.
Hex Value Reference
| Character | Hex | Decimal |
|---|---|---|
| A | 41 | 65 |
| a | 61 | 97 |
| 0 | 30 | 48 |
| (space) | 20 | 32 |
🎨 Hex in Design
Web developers know hex as color codes (#FF5733). The same principle applies—RGB values are stored as 3 hex bytes. #FF0000 = 255 red, 0 green, 0 blue.
Common Uses of Hex
Web Colors
CSS colors like #4A90D9 use hex notation. Each pair represents red, green, and blue intensity from 00 (0) to FF (255).
Memory Addresses
Debugging tools, pointers, and low-level programming use hex addresses like 0x7fff5fbffc00. It's more compact than decimal for large numbers.
File Signatures
File types have "magic numbers"—hex sequences identifying them. PDFs start with 25 50 44 46 (which is "%PDF" in ASCII).
Frequently Asked Questions
Why 0-9 and A-F?
Hex needs 16 symbols. We use 0-9 (ten digits) plus A-F (six letters) to represent values 10-15. Case doesn't matter—"FF" equals "ff".
How is hex different from Base64?
Both encode binary data as text. Hex is simpler (1 byte = 2 chars) but less efficient. Base64 is more compact (3 bytes = 4 chars) but harder to read.
What's the 0x prefix?
"0x" indicates a hexadecimal number in many programming languages. It's optional here—our converter handles both "48656C6C6F" and "0x48656C6C6F".