Two symbols, many possible meanings
Binary code is how computers store everything, using only two symbols: 0 and 1. A group of eight of these digits is a byte, and a text standard such as ASCII or UTF-8 decides which byte patterns stand for which letters. For example, the capital letter A is 01000001 in ASCII.
Binary is base two: each position has a power-of-two weight. For example, 1010 represents 8 + 2 = 10 in decimal. Bit sequences can represent numbers, text, images or instructions; interpretation depends on the data format.
Digital logic commonly models two distinguishable states as zero and one. That model does not mean every physical transistor is restricted to exactly two possible states.
Text encodings define how characters become bytes. ASCII specifies seven-bit values; UTF-8 stores ASCII in one byte and uses multiple bytes for other Unicode scalars. A code point is not generally the same number as an encoded byte.
How text becomes bytes and back
TextToolbox encodes valid scalar strings as UTF-8 and displays each byte as eight bits. A uses the byte 01000001; é uses 11000011 10101001. Joined emoji and accented sequences may contain multiple code points and bytes, even when they look like one character.
Decoding first validates complete byte notation, then checks UTF-8. Incomplete groups and malformed byte sequences produce errors rather than partial or replacement text. A leading U+FEFF is deliberately retained. Other encodings need their own decoder.
Spaced, continuous, prefixed and extra-spaced presentations describe the same payload bytes. Separators and 0b prefixes are notation, not payload bits. The converter does not encrypt data or produce executable CPU instructions.
This converter uses eight bits per byte, which gives 256 possible byte values. Use explicit units: one kilobyte (kB) is 1,000 bytes, while one kibibyte (KiB) is 1,024 bytes.
One hexadecimal digit represents four bits. The byte 11111111 is FF in hexadecimal and 255 in decimal, but that number alone does not identify a Unicode character or tell you an encoding.
Worked bit patterns, including ones that fail
- Binary number: 1010 equals decimal 10.
- UTF-8: 01001000 01100101 01101100 01101100 01101111 decodes to Hello.
- UTF-8: 00110001 00110000 00110000 decodes to the string 100, not a binary integer conversion.
- UTF-8: 11000011 10101001 decodes to é, U+00E9.
- UTF-8: 11110000 10011111 10011000 10000000 decodes to grinning face, U+1F600.
- 010000010 is an incomplete byte sequence; 11111111 is a complete byte but invalid UTF-8.
Lessons, puzzles and data-format study
- Encoding lessons: compare ASCII with accented and supplementary code points.
- Declared UTF-8 exercises: inspect byte boundaries and confirm a reversible helper conversion.
- Text puzzles: share an encoded clue with its encoding and byte notation stated.
- Data-format study: distinguish a bit pattern from its interpretation as text, a number or an instruction.