btoa() for Base64 encoding. These methods are part of the
window object and are only available in the browser.
Luckily, Node.js provides a native
Buffer module that can be used to perform Base64 encoding and decoding.
Buffer is available as a global object, and you don't need to explicitly require this module in your application.
Buffer represents binary data in the form of a sequence of bytes. The
Buffer object provides several methods to perform different encoding and decoding conversions. This includes to and from UTF-8, UCS2, Base64, ASCII, UTF-16, and even the HEX encoding scheme.
Let us look at the below examples that explain how to use the
Buffer object to perform Base64 encoding and decoding in a Node.js application.
To convert a string into a Base64 encoded string, we first create a buffer from the given string using the
Buffer.from() method. This method takes two parameters, a plain-text string, and the character encoding, and creates a buffer or binary data array for the given encoding. If no character encoding is specified, UTF-8 will be used as the default.
Here is an example:
// plain-text string const str = 'Base64 Encoding in Node.js'; // create a buffer const buff = Buffer.from(str, 'utf-8'); // decode buffer as Base64 const base64 = buff.toString('base64'); // print Base64 string console.log(base64); // QmFzZTY0IEVuY29kaW5nIGluIE5vZGUuanM=
In the above example, we created a buffer from the string and used the
toString() method to decode the buffer as a Base64 string. The second parameter in
Buffer.from() is optional when dealing with plain-text (UTF-8) strings.
The Base64 decoding process is very much similar to the encoding process. All you need to do is create a buffer from the Base64 encoding string by using
base64 as the second parameter to
Buffer.from() and then decode it to the UTF-8 string by using the
Here is what it looks like:
// Base64 encoded string const base64 = 'QmFzZTY0IEVuY29kaW5nIGluIE5vZGUuanM='; // create a buffer const buff = Buffer.from(base64, 'base64'); // decode buffer as UTF-8 const str = buff.toString('utf-8'); // print normal string console.log(str); // Base64 Encoding in Node.js
That's all for Base64 encoding and decoding in Node.js. We looked at how to use the native
Buffer module to perform the Base64 encoding and decoding in a Node.js application. The
Buffer object is not just limited to Base64 conversions. You can even use it to perform ASCII, HEX, UTF-16, and UCS2 encodings and decodings.