QQuickKit

Number Base Converter

Convert integers between binary, octal, decimal and hexadecimal. Type in any field and all other bases update instantly.

About This Tool

Number base conversion is a fundamental skill in programming and computer science. Binary (base 2) is the language of hardware and bitwise operations, octal (base 8) compactly represents Unix file permissions, decimal (base 10) is everyday arithmetic, and hexadecimal (base 16) is the standard for memory addresses, color codes, and byte sequences. QuickKit's Number Base Converter converts between all four bases simultaneously, supporting arbitrarily large integers via JavaScript BigInt.

Features

  • ✓Four Bases Simultaneously — Edit any of the four fields (binary, octal, decimal, hex) and all others update instantly.
  • ✓BigInt Support — Handles arbitrarily large integers beyond the 53-bit JavaScript Number limit using native BigInt arithmetic.
  • ✓Input Validation — Each field only accepts valid characters for its base, with a clear error message for invalid input.
  • ✓Uppercase Hex — Hexadecimal output uses uppercase letters (A–F) for maximum readability in code and documentation.
  • ✓Instant Conversion — No buttons to click — just type in any field and see all four representations update in real time.

FAQ

Why do programmers use hexadecimal?
Hexadecimal is a compact notation for binary data. Each hex digit represents exactly 4 bits, so a byte (8 bits) is always two hex digits. This makes hex ideal for memory addresses, color codes (e.g. #FF6600), SHA hash digests, and MAC addresses — all cases where a dense, human-readable representation of raw bytes is needed.
When is binary used in programming?
Binary is used in bitwise operations (AND, OR, XOR, NOT, shifts), flag fields (e.g. Unix permissions 0b110 = rw-), network subnet masks, and low-level hardware programming. Modern code often writes binary literals with a 0b prefix for clarity instead of converting to decimal mentally.
What is octal used for?
Octal (base 8) is most commonly associated with Unix file permission modes. chmod 755 means owner can read/write/execute (7 = 111₂), group can read/execute (5 = 101₂), others can read/execute. Some older systems and languages also use octal escape sequences in strings (e.g. \077).
What is a BigInt and why is it needed?
JavaScript's standard Number type is a 64-bit float, which can only represent integers exactly up to 2^53 − 1 (about 9 quadrillion). For numbers larger than that — such as 64-bit hashes, 128-bit UUIDs, or large cryptographic values — BigInt provides arbitrary-precision integer arithmetic. This converter uses BigInt to handle numbers of any size without precision loss.

Further Reading