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Octal to Binary Converter

Expand an octal number — such as a chmod permission like 755 — back into the individual bits it stands for. Everything runs locally in your browser.

=
11111111

Octal (base 8) in, Binary (base 2) out.

How it works

Each octal digit is exactly three bits: 7 = 111, 5 = 101, so 755 = 111 101 101.

Examples

FAQ

How do I convert octal to binary?

Each octal digit is exactly three bits: 7 = 111, 5 = 101, so 755 = 111 101 101. Or just paste your octal value into the box above and the binary result appears instantly.

Does this Octal to Binary converter run in my browser?

Yes. The conversion happens entirely client-side — nothing you type is uploaded — and it uses big-integer math, so even very long octal numbers convert exactly.

What is the largest number I can convert?

There is no practical limit. Because the converter works with arbitrary-precision integers, a octal value of any length converts without rounding or overflow.

Need other bases, custom radixes, or two-way editing? Use the full Number Base Converter.

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