Convert text or files to Base64 and back. Commonly used to embed images in code or safely pass text through systems that only handle plain characters.

Base64 encode/decode for text (UTF-8) and binary files. Standard RFC 4648 alphabet. File mode reads via FileReader API and outputs a data URI or raw Base64 string.

btoa()/atob() with TextEncoder for proper UTF-8 handling (avoids the BOM/non-ASCII pitfall of raw btoa). File mode: FileReader.readAsDataURL() yields a data URI; raw mode strips the MIME prefix. All local, no network.