How to Encode Base64 in JavaScript Without Breaking Unicode

Base64 encoding is one of those small developer tasks that looks simple until you hit Unicode characters, files, APIs, or URL-safe formats. In JavaScript, many tutorials show this: btoa ( " Hello World " ); And yes, it works. But only for simple ASCII text. Once you try to encode something like: " Café 🚀 " you may run into errors or broken output. In this guide, we’ll cover how Base64 encoding works in JavaScript, when btoa() is enough, when it is not, and how to encode text, Unicode, files, im