base32

base32 encodes binary data into set of ASCII chars, 26 letters (A-Z) & 2-7 numerals.

It takes 5 bit of input and converts it into a char. Since data is generally represented in 8-bits byte, it processes a 5 byte input chunk (40 bit) and generates a 8 chars of output. Padding '=' is added at the end if input is not a multiple of 5. Padding is extra, and data can be decoded (although with errors) without it.

Use cases

• TOTP
• case insensitive systems like dns, filesystem etc

base64

base64 encodes binary data into 64 ASCII chars:

• A-Z
• a-z
• 0-9
• • / (2 special chars)
• = (padding at the end)

Processes a 6 bit input to one char. Takes 3 bytes (24 bit) to produce 4 chars. If input is not a multiple of 3 bytes, padding is added at the end.

Use cases

• converts binary data into representable text
  • email attachments
  • image css in html

URL encoding

URL encoding replaces unsafe chars with % followed by 2 digit hex value. Almost all chars are unsafe except few.

Sources

Related