Base64 encode a file

Turn a file into a block of plain text.

Base64 rewrites arbitrary bytes using only letters, digits and two punctuation marks, which lets a file travel through channels that only accept text — an email body, a configuration file, a data URL embedded in a stylesheet.

It is not encryption and it is not compression. The result is about a third larger than the original and can be decoded by anyone in a second.

Large files make very large text. A few hundred kilobytes is comfortable to paste anywhere; a video is not, and the editor you paste into will complain long before this page does.

Accepts: */*

Questions

Is Base64 encryption?
No, and this matters. Base64 is a way of writing bytes as plain letters and digits. Anyone can decode it instantly. It hides nothing.
Why is the result bigger than the file?
Base64 uses four characters for every three bytes, so expect about a third more.