Encode base64 in JavaScript

Why encode base64 javascript?

Encode base64 in JavaScript is one of the most common tasks developers hit when working with APIs, files, email attachments, and data URIs.

More Base64 guides on base64app — with copy-paste code and a free browser tool you can use without installing anything.

Quick reference

Base64 maps every 3 bytes to 4 ASCII characters. Padding with = may appear at the end. URL-safe variants swap +/ for -_.

When in doubt, paste your string into the tool below — base64app auto-repairs whitespace, data: prefixes, and padding issues.

Copy-paste code

const text = 'Hello, base64app!';
const b64 = btoa(text);
console.log(b64); // SGVsbG8sIGJhc2U2NGFwcCE=

Related guides

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• Encode base64 in Node.js
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• Convert string to base64
• URL-safe base64 encoding
• Decode base64 in JavaScript