Convert between binary, decimal, octal, and hexadecimal instantly. Also convert text to binary and binary to text.
Type in any field — all others update instantly
Enter a number in any field above to begin converting
Convert plain text to 8-bit ASCII binary groups and back
Binary output will appear here
Decoded text will appear here
| Decimal | Binary | Octal | Hex |
|---|---|---|---|
| 0 | 0 | 0 | 0 |
| 1 | 1 | 1 | 1 |
| 8 | 1000 | 10 | 8 |
| 10 | 1010 | 12 | A |
| 15 | 1111 | 17 | F |
| 16 | 10000 | 20 | 10 |
| 255 | 11111111 | 377 | FF |
| 256 | 100000000 | 400 | 100 |
| 65535 | 1111111111111111 | 177777 | FFFF |
| 4294967295 | 11111111111111111111111111111111 | 37777777777 | FFFFFFFF |
The Binary Converter is a free online tool that instantly converts numbers between the four numeral systems used in computing: binary (base 2), decimal (base 10), octal (base 8), and hexadecimal (base 16). Type in any field and all others update in real time.
It also includes a Text ↔ Binary converter that transforms any plain text string into space-separated 8-bit binary groups (ASCII encoding), and reverses binary strings back into readable text.
Every number can be expressed in any base. The value doesn't change — only the representation does. Base 2 uses only 0 and 1. Base 8 uses 0–7. Base 10 uses 0–9 (our everyday system). Base 16 uses 0–9 and A–F to represent values 0 through 15 with a single character.
Programmers work with these bases constantly — binary for bitwise operations, hex for memory addresses and color codes, octal for Unix file permissions. This tool removes the mental overhead so you can focus on your code.
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Each binary digit (bit) represents a power of 2, starting from the rightmost bit (2⁰). To convert, multiply each bit by its corresponding power of 2 and sum the results. For example, 1010 in binary = 1×8 + 0×4 + 1×2 + 0×1 = 10 in decimal. This tool does it instantly — just type in the binary field.
Hexadecimal (base 16) uses digits 0–9 and letters A–F to represent values 0–15 in a single character. It is widely used in programming because it maps neatly to binary: each hex digit represents exactly 4 bits (a nibble). This makes reading memory addresses, color codes, and byte values far more compact than binary.
Octal (base 8) was historically used in older computing systems and is still seen in Unix/Linux file permissions (e.g., chmod 755). Each octal digit represents exactly 3 bits, making it a compact shorthand for binary values.
This tool supports values up to the 32-bit unsigned integer maximum: 4,294,967,295 in decimal (FFFFFFFF in hex, 37777777777 in octal, or 11111111111111111111111111111111 in binary).
Each character is converted to its ASCII (Unicode code point) value, which is then represented as an 8-bit binary number. For example, "H" is ASCII 72 → 01001000 in binary. Spaces separate each character's 8-bit group.
No. You can type hex digits in upper or lower case (e.g., "ff" or "FF"). The output is always displayed in uppercase for consistency.