Binary Converter — Convert Text & Numbers to Binary Online Free
Instantly convert text to binary code, binary back to text, decimal numbers to binary, and binary to decimal. Also converts to hex and octal. Free, private, works in your browser.
How Binary Works
Binary is the fundamental language of computers. Every piece of digital data — text, images, video, programs — is ultimately stored as sequences of 0s and 1s.
Binary uses only two digits: 0 and 1. Each position represents a power of 2 — just like decimal uses powers of 10. 1101 = 8+4+0+1 = 13.
One binary digit is called a bit. 8 bits = 1 byte, which can represent 256 different values (0-255). A byte stores one ASCII character.
Text is stored by converting each character to its ASCII code, then to binary. "A" → 65 → 01000001. "Hello" = 5 bytes = 40 bits.
Hexadecimal (base-16) is a compact way to write binary. Every 4 bits = 1 hex digit. 1111 0000 = F0. Programmers use hex to read binary more easily.
Electronic transistors have two states — on and off — making binary the natural choice. A transistor that is on = 1, off = 0. Modern CPUs have billions of transistors.
Octal (base-8) groups binary in sets of 3 bits. Used in Unix file permissions (chmod 755) where each digit represents read/write/execute access.
Binary Conversion Examples
A → ASCII 65 → 64+1 → 2⁶+2⁰ → 01000001. Each text character becomes an 8-bit binary byte.
13 = 8+4+1 = 2³+2²+2⁰ → 1101. Divide by 2 repeatedly: 13÷2=6r1, 6÷2=3r0, 3÷2=1r1, 1÷2=0r1 → read remainders bottom to top: 1101.
1×2³ + 0×2² + 1×2¹ + 0×2⁰ = 8+0+2+0 = 10. Read each bit position as a power of 2 and add them up.
Frequently Asked Questions
How do I convert text to binary?
Each character is converted to its ASCII code, then the code is converted to an 8-bit binary number. For example: H=72=01001000, e=101=01100101, l=108=01101100, and so on. This tool does it automatically — just type in the left box.
How do I convert a decimal number to binary?
Repeatedly divide by 2, writing down the remainder each time, until you reach 0. Read the remainders from bottom to top. Example: 10 → 10÷2=5r0, 5÷2=2r1, 2÷2=1r0, 1÷2=0r1 → binary: 1010.
How do I convert binary to decimal?
Multiply each bit by its place value (powers of 2) and add. For 1010: (1×8)+(0×4)+(1×2)+(0×1) = 8+0+2+0 = 10. The rightmost bit is 2⁰=1, next is 2¹=2, 2²=4, 2³=8, and so on.
What is a bit and a byte?
A bit is a single binary digit — either 0 or 1. A byte is 8 bits grouped together, which can represent values from 0 (00000000) to 255 (11111111). One byte stores one ASCII character. 1,024 bytes = 1 kilobyte, 1,024 kilobytes = 1 megabyte.
What is binary used for in programming?
Binary is used in bitwise operations (AND, OR, XOR, NOT), bit flags, permission systems (Unix chmod), network masks, graphics color channels, compression algorithms, and any low-level systems programming where individual bits need to be manipulated.
Is my text sent to a server?
No. All conversion happens entirely in your browser using JavaScript. Your text is never sent to any server, never stored, and never shared.
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