Binary (Base 2)
0b prefix · digits: 0, 1
Octal (Base 8)
0o prefix · digits: 0–7
Decimal (Base 10)
No prefix · digits: 0–9
Hexadecimal (Base 16)
0x prefix · digits: 0–9, A–F
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Bitwise Operations
ASCII / Character Lookup
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Number Bases Explained
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Binary (base 2) uses only 0 and 1 — the language of computers. Each binary digit is one "bit". Eight bits make a byte (0–255 in decimal). Hexadecimal (base 16) is used in programming because each hex digit maps exactly to 4 bits: 0xFF = 1111 1111 = 255. Octal (base 8) was common in early computing. Memory addresses, colors (#RRGGBB), and CPU instructions are all commonly expressed in hex.
Use the Binary Converter above — enter your values and get instant results. This free online tool calculates how to convert decimal to binary without any download or signup required. Results update in real time as you type.
Use the Binary Converter above — enter your values and get instant results. This free online tool calculates binary to hex converter without any download or signup required. Results update in real time as you type.
0xFF is hexadecimal notation for the number 255 in decimal (1111 1111 in binary). The 0x prefix indicates hexadecimal. F in hex = 15 decimal = 1111 binary. Two F's (FF) = 15×16 + 15 = 255. This is the maximum value of a single byte, used for fully opaque alpha in RGBA colors, and for bitmask operations to isolate the lowest byte.
XOR (exclusive OR) outputs 1 when the inputs differ and 0 when they're the same. It's used in cryptography (simple XOR cipher), checksums (parity bits), bit toggling (flip a bit with XOR 1), and swapping two variables without a temp: a ^= b; b ^= a; a ^= b. It's also used in RAID storage for parity data and in error detection codes.