What Number Base Converter Does and Why It Matters
Number Base Converter converts a number between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16) representations. Choose one of the four supported bases, type a signed whole integer, and the equivalent value in the other three is shown immediately — the kind of conversion that comes up constantly in programming and electronics but is tedious and error-prone to do by hand for anything beyond small numbers.
Hexadecimal shows up in color codes, memory addresses, and byte-level data; binary is how values are actually represented at the hardware level and shows up in bitwise logic and low-level debugging; octal is less common today but still appears in file permission notation (like Unix chmod values). Converting between them by hand means repeated division or grouping bits in fours, which is easy to get wrong on anything longer than a couple of digits — this tool uses BigInt arithmetic so supported whole-integer conversions are not rounded at JavaScript's Number safe-integer boundary.
How to Use Number Base Converter
- Choose the base of the number you're starting with (binary, octal, decimal, or hexadecimal).
- Type the value into that field, using only the digits valid for that base.
- The equivalent value in the other three supported bases updates automatically.
- Negative values use a leading minus sign. This is signed-magnitude text conversion, not a fixed-width two's-complement representation.
Valid Digits and Limitations
- Binary: digits 0–1 only
- Octal: digits 0–7 only
- Decimal: digits 0–9
- Hexadecimal: digits 0–9 and letters A–F (case-insensitive)
Invalid digits are rejected. The tool accepts optional leading minus signs and whole integers only; fractional, fixed-point, floating-point, and fixed-width two's-complement representations are outside its supported contract.
Privacy and Security
Values you enter are converted directly in your browser and are never sent anywhere or stored.
Frequently Asked Questions
Why is my hexadecimal value shown with uppercase letters when I typed lowercase?
Hex digits A–F are case-insensitive by convention — the tool normalizes the display case, but the underlying value is identical either way.
Can I convert negative numbers?
Yes. A leading minus sign is preserved across bases. The output does not claim to be a fixed-width two's-complement encoding; that representation depends on a bit width the tool does not ask you to choose.
What's the largest number I can convert?
The converter uses the browser's BigInt primitive, so it is not limited by Number.MAX_SAFE_INTEGER. Practical limits come from browser memory and input size rather than floating-point integer precision.