Converters

Binary Converter

Free binary converter. Convert numbers between binary, octal, decimal, and hexadecimal with input validation and all four bases shown at once.

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Deep dive guides

A LITTLE CONTEXT · 3 MIN READBinary Conversion: Four Bases From One Input

All 7 related guides

Number Base Systems Explained: Binary, Hex, and Beyond — A plain-English guide to number bases: why we use base 10, how binary and hex work, positional notation, and why computers love base 2 and 16.
KB vs KiB: Why Your Drive Looks Smaller Than Advertised — KB is 1,000 bytes and KiB is 1,024; the 2.4%-per-step compounding gap is why a "500 GB" drive reports about 465.
Human-Readable Sizes: How Byte Formatters Pick Their Words — How best-fit formatting turns 1536 into “1.5 KiB”: unit selection, rounding, and the choices behind every ls -h.
ASCII Codes Explained: Turning Characters into Numbers — How each character maps to a number: the ASCII layout, converting text to codes and back, decimal vs hex, and where Unicode takes over.
Hex Encoding Explained: See Any Text as Raw Bytes — How hex encoding turns text into byte pairs — UTF-8 surprises included — plus the formatting options (0x, spaces, uppercase) that match your target system.
Data Size Conversion: The 1024 Ladder, Used Honestly — This converter speaks the traditional 1024 ladder — 1 GB is 1,024 MB — and here is when that is the right reading.
Binary Conversion: Four Bases From One Input — One validated input, all four programming bases out at once — plus the quirks and the 2^53 ceiling.

How binary converter works

Numbers can be written in any base. Computers most often use base 2 (binary, digits 0 and 1), base 8 (octal, 0-7), base 10 (decimal, our everyday system), and base 16 (hexadecimal, 0-9 and a-f). Each base is just a different way of grouping the same value; conversion works by parsing the input in its source base and re-formatting it in the target base.

Enter a value, choose the base it is written in (from), and the base you want (to). The converter validates the digits against the source base — for example it rejects "102" as binary because 2 is not a binary digit — then parses and re-formats. It always shows the value in all four bases so you can see the whole picture at once.

Hexadecimal is common in programming for memory addresses and color codes, binary for bit-level work, and octal for Unix file permissions. This converter handles positive integers in any of the four bases and is a quick reference for translating between them.

Frequently asked questions

How do I convert decimal to binary?

Divide the number by 2 repeatedly and read the remainders from bottom to top. 255 in decimal is 11111111 in binary. This converter does it instantly and also shows the octal and hex equivalents.

What bases does it support?

Binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). Pick the source base the value is written in and the target base you want.

Why was my input rejected?

Each digit must be valid for the source base. "102" is not valid binary (2 is not a binary digit), and "gg" is not valid hex. The converter checks this before parsing and shows a clear error.

Does it support negative or fractional numbers?

Negative numbers are accepted in every base (type -5 in decimal or -101 in binary) and shown as signed values. For the fixed-width view hardware uses, pick a two's-complement width (8/16/32 bit): -5 in 8-bit shows as 11111011. Fractional values are not supported because their base representations can be infinite.

Binary Converter

Deep dive guides

How binary converter works

Frequently asked questions

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