Base64

Base64 is a binary-to-text encoding scheme that translates 8-bit binary data into a portable 64-character ASCII subset (RFC 4648).

This standard maps 6-bit chunks of data to a specific set of 64 characters: uppercase letters, lowercase letters, digits, and two symbols (+ and /). It increases data size by roughly 33 percent but ensures safe passage across systems that only support text. Developers use it for embedding small images in CSS files, transmitting email attachments via MIME, and passing complex data in URLs. The process uses equal signs (=) for padding to ensure the final output is a multiple of four bytes.

https://datatracker.ietf.org/doc/html/rfc4648