About
Why this exists
The problem
Most online Base64 tools upload your file to a server, encode it there, and hand back a download link — for an operation your own browser performs in microseconds. If the file is a client contract, an API key dump or a private key, that upload is the whole problem.
The approach
freebase64encode.com is a single static HTML page. The encoder is a few kilobytes of JavaScript implementing RFC 4648 directly. There is no backend, no database and no upload endpoint, so there is nothing to breach and nothing to log.
What it handles
Text in six character sets, files of any size your device can hold, and images with a live preview plus a ready-to-paste data URI. It supports the standard alphabet, the URL-safe alphabet from RFC 4648 §5, MIME 76-character line splitting, LF and CRLF separators, and per-line encoding.
Standards
Base64 is specified in RFC 4648. The MIME variant with 76-character lines comes from RFC 2045. The URL-safe variant used by JSON Web Tokens is RFC 4648 §5.
Cost
Free, with no ads, no upsell and no account. It stays that way.