Base64

Base64 turns binary data into plain ASCII text so it can safely travel through systems that only handle text, like email bodies, JSON payloads, or embedding a small image directly in CSS/HTML.

Base64 packs 3 bytes of input into 4 output characters, so encoded text is roughly 33% larger than the original. This is expected and not a sign of an error.

No. Encoding and decoding happen entirely in your browser using JavaScript — nothing is sent to a server, so it works fine offline too.