Bytes explain the result
UTF-8 represents text as bytes. Each row shows the binary, decimal and hexadecimal form of one byte. ASCII accepts only its basic character range; choose UTF-8 for accents and emoji. To represent those bytes with a more compact alphabet, use Base64.
A worked example
01001111 01000011 01010100 01001111 decodes to OCTO. Each group has 8 bits. An octopus emoji takes several UTF-8 bytes.
Before you use the result
Spaces, underscores or continuous complete bytes are accepted. Incomplete groups and invalid characters are reported. A byte may be part of a character, so it cannot always be displayed as a letter by itself.