Octal to Binary Converter

Free online octal to binary converter with steps — instant, accurate octal to binary conversion in your browser.

Supports arbitrarily large non-negative integers (BigInt under the hood).

About octal to binary conversion

Number bases are just different ways of writing the same value: binary (base 2) uses digits 0–1, octal (base 8) uses 0–7, decimal (base 10) uses 0–9 and hexadecimal (base 16) uses 0–9 plus A–F. This converter parses your input as an arbitrary-precision integer and re-renders it in the target base — instantly and privately, in your browser.

Quick reference

  • 1010 in binary = 12 in octal = 10 in decimal = A in hexadecimal
  • Hexadecimal digits: A=10, B=11, C=12, D=13, E=14, F=15
  • Each octal digit maps to exactly 3 binary digits; each hex digit maps to exactly 4

Frequently asked questions

How do I convert octal to binary manually?

Expand each octal digit into its 3-bit binary form and join them together.

What is octal 755 in binary?

755 in octal equals 111101101 in binary.

Is this converter free and private?

Yes — free, no sign-up, and the conversion runs locally in your browser using arbitrary-precision integers. Nothing is uploaded.

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