Base64 Encoder / Decoder

Encoding Client-side base64 encode decode encoding utf-8

This tool runs entirely client-side, in your browser: your data is never sent anywhere.

What it does

Converts text to and from Base64, a common encoding used to represent binary data as ASCII text (e.g. embedding images in CSS, Basic Auth headers, JWT segments).

Try it

How it works

Encode: the input string is UTF-8 encoded, then converted to Base64 using the browser's native btoa, with a small wrapper to safely handle multi-byte UTF-8 characters (emoji, accents, etc.).
Decode: the reverse process using atob, decoding back to a UTF-8 string. If the input isn't valid Base64, an error is shown.

Everything runs locally in your browser — nothing is uploaded anywhere.