Binary Converter

Binary Converter: Binary, Decimal, Hex and Text

Type a number in the binary field and the decimal, octal and hexadecimal fields follow at once, and the other way round. The "Text and codes" tab turns text into binary and binary into text, and the "Float and hex" tab shows how a decimal number is stored in 32 or 64 bits. Everything happens in your browser: nothing you type is uploaded.

What is binary

Binary is the number system with two digits, 0 and 1: base 2. Computers use it because a circuit is either on or off. One binary digit is a bit, eight bits make a byte, and one byte holds a number from 0 to 255 or one letter of English text.

How to convert binary to decimal and back

Every position is worth twice the one to its right: 1, 2, 4, 8, 16... The binary number 1011 is 1 x 8 + 0 x 4 + 1 x 2 + 1 x 1 = 11. To go the other way, divide the decimal number by 2 again and again and read the remainders from the last to the first: 13 gives 1101. The converter does this for numbers of any size, also with many hundreds of digits, without losing a digit.

Binary to text and text to binary

Text is stored as bytes, and the converter shows each byte as eight binary digits. "Hi" is 01001000 01101001. Letters of the English alphabet take one byte, other letters take two to four bytes (the UTF-8 encoding, which covers all languages and emoji). You can paste the binary with spaces, commas or line breaks between the bytes, or as one long run of digits.

Negative numbers and the bit width

Choose 8, 16, 32 or 64 bits to see the number the way a program stores it: with all the bits written, and a negative number as two's complement. In 8 bits, -1 is 11111111 and -128 is 10000000. A number that does not fit the chosen width is reported with the range that fits.

Limitations

• The numbers tab works with whole numbers. For a number with a decimal point, such as 0.1, use the "Float and hex" tab, which shows its 32 or 64 bit pattern.
• Text is converted as UTF-8. Text saved in an old code page may give other bytes.
• Numbers of up to 5000 digits are read.