About the Number Base Converter
Computers represent numbers in several bases: binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). Converting between them by hand is slow and mistake-prone. This free online Number Base Converter does it instantly and accurately.
Type a value into any field — binary, octal, decimal, or hex — and the other three update in real time. It uses arbitrary-precision arithmetic, so even very large numbers convert exactly without rounding errors.
How to convert number bases
- Type a number into the base you already have (for example, decimal).
- The binary, octal, and hexadecimal equivalents update instantly.
- Edit any field to convert from that base instead.
- Click the copy icon next to any value to copy it.
- Invalid digits for a base are flagged so you can correct them.
Features
- Two-way conversion across binary, octal, decimal, and hex.
- Real-time updates as you type in any field.
- Arbitrary-precision — handles very large integers exactly.
- Input validation with clear error messages.
- One-click copy for each base — all in your browser.
Number Base Converter FAQs
How do I convert decimal to binary?
Type your number into the decimal field and read the binary field — the tool converts it instantly. Internally it repeatedly divides by 2 and reads the remainders.
What is hexadecimal used for?
Hexadecimal (base 16) is compact and maps neatly to binary, so it is widely used for memory addresses, color codes, and byte values in programming.
Can it handle very large numbers?
Yes. The converter uses arbitrary-precision integers, so large values convert exactly without the rounding errors of normal floating-point math.
Why is my input marked invalid?
Each base only allows certain digits — binary allows 0 and 1, octal 0–7, decimal 0–9, and hex 0–9 and A–F. Characters outside the allowed set are flagged.
Is this base converter free?
Yes, it is completely free, needs no signup, and runs entirely in your browser.
