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Octal to Binary Converter

Convert octal (base-8) numbers to binary (base-2).

Try an example:
Binary (2)
11111111
Octal (8)
377
Decimal (10)
255
Hexadecimal (16)
ff

Converting Octal to Binary

Each octal digit expands to exactly three binary bits, so converting is a quick per-digit lookup.

How to convert Octal to Binary by hand

  1. Replace each octal digit with its 3-bit binary equivalent (0 = 000 … 7 = 111).
  2. Concatenate the groups in order.
  3. Optionally drop any leading zeros.

Worked example

377 (octal)11111111 (binary)3 = 011, 7 = 111, 7 = 111.

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Frequently asked questions

How do I convert Octal to Binary?

Replace each octal digit with its 3-bit binary equivalent (0 = 000 … 7 = 111). Concatenate the groups in order. Optionally drop any leading zeros. Or just use the converter on this page — it does it instantly. Example: 377 (octal) becomes 11111111 (binary).

What is 377 (octal) in binary?

377 (octal) converts to 11111111 (binary). 3 = 011, 7 = 111, 7 = 111.

Is this converter free and private?

Yes — it is free and unlimited, and the conversion runs entirely in your browser, so nothing is uploaded to a server.