Number Base Converter

Binary, octal, decimal, and hex

Computers count in different bases than people do. This converter takes a whole number in any of the four common bases — binary (2), octal (8), decimal (10), or hexadecimal (16) — and shows it in all of them at once.

What the bases mean

• Binary uses only 0 and 1 — the language of digital circuits.
• Octal groups bits in threes; still seen in file permissions.
• Decimal is everyday base-10.
• Hexadecimal uses 0–9 and A–F, compactly representing bytes and colors.

FAQ

Can it handle very large numbers?

Yes — conversions use big-integer math, so numbers far beyond the usual 64-bit limit convert exactly with no rounding. Prefixes like 0x, 0b, and 0o are accepted and ignored.

Is this base converter free, and does my input stay private?

Yes — it's free with no sign-up, and the conversion runs entirely in your browser. Nothing you type is sent to a server, so you can use it as much as you like.

Can it convert negative numbers or decimals?

It works on non-negative whole numbers. Fractional values (like binary after a point) and two's-complement negative representations aren't handled, so stick to integers for accurate results across all four bases.

Why does hexadecimal use letters like A–F?

Hexadecimal is base-16, so it needs sixteen distinct digit symbols. After 0–9 it borrows the letters A–F to represent the values 10 through 15, which lets a single hex digit stand for four binary bits and makes byte values compact to read.

What does the 0x, 0b, or 0o prefix mean?

Those are common programming notations: 0x marks a hexadecimal number, 0b binary, and 0o octal. You can paste numbers with these prefixes and the converter recognizes and strips them automatically.

Does it work on mobile?

Yes. It's fully responsive and runs in any mobile browser, converting between binary, octal, decimal, and hex instantly on a phone or tablet.