Binary / Hex / Decimal / Text Converter
Convert between binary, hexadecimal, decimal, octal, and text (ASCII/UTF-8) instantly. Enter a value in any base and see all other representations. Supports large numbers via BigInt and full Unicode text including emoji. 100% browser-based.
Key Facts
- Binary (Base 2): Uses only 0 and 1. The fundamental language of all digital computers. Every piece of data is ultimately stored as binary
- Hexadecimal (Base 16): Uses 0-9 and A-F. Compact representation of binary (1 hex digit = 4 binary digits). Used for memory addresses, color codes, MAC addresses, and cryptographic hashes
- Decimal (Base 10): Standard human number system. Used for arithmetic, user-facing values, and most everyday computation
- Octal (Base 8): Uses 0-7. Primarily used for Unix file permissions (chmod 755). Each octal digit maps to exactly 3 binary digits
- ASCII/UTF-8: ASCII uses 7 bits for 128 characters. UTF-8 extends this to all Unicode (1.1 million+ code points) using 1-4 bytes per character, backward-compatible with ASCII
Where Hex and Binary Are Used
- CSS Color Codes: #FF5733 = RGB(255, 87, 51). Each pair of hex digits represents one color channel (red, green, blue) from 00 (0) to FF (255)
- MAC Addresses: AA:BB:CC:DD:EE:FF — six hex byte pairs identifying network interfaces
- Memory Addresses: 0x7FFF5FBFF8A0 — hex representation of RAM locations in debuggers and system tools
- Cryptographic Hashes: SHA-256 outputs 64 hex characters (256 bits). See our SHA-256 Hash Generator
- File Permissions: chmod 755 = rwxr-xr-x. Octal 7=111 (rwx), 5=101 (r-x) in binary
- Unicode Code Points: U+1F512 = 🔒. Hex representation of character positions in the Unicode standard
Binary-Hex Quick Reference (Nibbles)
- 0000 = 0 • 0001 = 1 • 0010 = 2 • 0011 = 3
- 0100 = 4 • 0101 = 5 • 0110 = 6 • 0111 = 7
- 1000 = 8 • 1001 = 9 • 1010 = A • 1011 = B
- 1100 = C • 1101 = D • 1110 = E • 1111 = F
Frequently Asked Questions
How do you convert binary to hexadecimal?
Group the binary digits into sets of 4 from right to left, padding with leading zeros if needed. Convert each group to its hex equivalent: 0000=0, 0001=1, ..., 1010=A, 1011=B, 1100=C, 1101=D, 1110=E, 1111=F. For example, binary 11010110 groups as 1101 0110, converting to D6 in hex.
What is hexadecimal used for in programming?
Hexadecimal is used for memory addresses, CSS/HTML color codes (#FF5733), MAC addresses (AA:BB:CC:DD:EE:FF), Unicode code points (U+1F512), cryptographic hashes (SHA-256 output), byte-level data inspection in hex editors, and debug output. It is more compact than binary while maintaining a direct mapping (1 hex digit = 4 binary digits).
What is the difference between ASCII and UTF-8?
ASCII uses 7 bits to represent 128 characters (English letters, digits, basic symbols). UTF-8 is a variable-width encoding (1-4 bytes per character) that is backward-compatible with ASCII but can represent all 1,114,112 Unicode code points, including international alphabets, CJK characters, and emoji.
What is octal and where is it used?
Octal (base-8) uses digits 0-7 and is primarily used in Unix/Linux file permissions. The command chmod 755 sets read-write-execute (7=111) for the owner, read-execute (5=101) for group and others. Each octal digit maps to exactly 3 binary digits, making it convenient for 3-bit permission fields.
Can this tool handle large numbers?
Yes. The tool uses JavaScript BigInt for numeric conversions, supporting arbitrarily large integers. For text mode, it converts each character individually to its byte representation, handling the full Unicode range including multi-byte emoji characters.