Base64 Encoder/Decoder for JavaScript
Free online base64 encoder/decoder with JavaScript code examples
Working with base64 encoder/decoder in JavaScript? Our free online base64 encoder/decoder helps JavaScript developers format, validate, and process data instantly. Below you will find JavaScript code examples using btoa/atob (built-in) so you can achieve the same result programmatically in your own projects.
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Open Base64 Encoder/DecoderJavaScript Code Example
// Encode
const encoded = btoa("Hello, World!");
console.log(encoded); // SGVsbG8sIFdvcmxkIQ==
// Decode
const decoded = atob(encoded);
console.log(decoded); // Hello, World!
// Node.js alternative:
// Buffer.from(text).toString('base64')Quick Setup
Library: btoa/atob (built-in)
// Built-in functions — no installation neededJavaScript Tips & Best Practices
- btoa/atob only handle ASCII; use Buffer in Node.js for UTF-8
- In Node.js: Buffer.from(str).toString('base64')
- For URL-safe Base64, replace + with - and / with _