How to use
- Pick Encode to turn text into Base64, or Decode to turn Base64 back into text.
- Paste or type your content into the input box.
- The result appears instantly in the output box.
- Click Copy to put the result on your clipboard.
About Base64
Base64 represents binary data using 64 printable ASCII characters. It exists because many older protocols — email being the classic example — could only reliably carry text, so binary payloads had to be reshaped into something that survives the trip.
The encoder reads three bytes at a time and rewrites them as four characters, which is
why Base64 output is roughly one third larger than its input. When the input length is
not divisible by three, = padding characters fill the gap.
A detail that trips people up: the browser’s built-in btoa() function throws an error
on any character above U+00FF, so naive implementations break the moment you paste
Chinese text or an emoji. This tool encodes the string to UTF-8 bytes first, which is
why non-English input round-trips correctly here.
Base64 is not a security measure. It is trivially reversible by design, and anything you encode should be considered public.