What Is Base64 Encoding?

Base64 is a binary-to-text encoding scheme that represents binary data using a set of 64 ASCII
characters (A–Z, a–z, 0–9, +, and /). It is commonly used to embed binary data — such as images
or files — in text-based formats like HTML, CSS, JSON, and email (MIME). When you encode data as
Base64, the output is roughly 33% larger than the original, but it is safe to transmit anywhere
that handles plain text.

How Does This Tool Work?

This encoder and decoder runs entirely in your browser using JavaScript’s built-in btoa()
and atob() functions, with full Unicode support via the TextEncoder API. Your data never
leaves your device — there are no server requests, no logging, and no tracking. You can encode plain
text by typing or pasting it, or encode files by dragging and dropping them into the upload area.

Common Uses for Base64

Developers use Base64 encoding to embed small images as data URIs in CSS or HTML, transmit binary
attachments in JSON APIs, encode authentication credentials for HTTP Basic Auth headers, store
binary data in text-only databases or configuration files, and encode email attachments via MIME.
This tool makes it easy to quickly encode or decode without installing any software.