Buffers can be used for taking a string or piece of data and doing Base64 encoding of the result. For example:
> console.log(Buffer.from("Hello World").toString('base64'));
SGVsbG8gV29ybGQ=
> console.log(Buffer.from("SGVsbG8gV29ybGQ=", 'base64').toString('ascii'))
Hello World
The Buffer constructor is a global object, so no require is needed. Buffers created with strings can take an optional encoding parameter to specify what encoding the string is in. The available toString and Buffer constructor encodings are as follows:
Answer from onteria_ on Stack Overflow'ascii' - for 7 bit ASCII data only. This encoding method is very fast, and will strip the high bit if set.
'utf8' - Multi byte encoded Unicode characters. Many web pages and other document formats use UTF-8.
'ucs2' - 2-bytes, little endian encoded Unicode characters. It can encode only BMP(Basic Multilingual Plane, U+0000 - U+FFFF).
'base64' - Base64 string encoding.
'binary' - A way of encoding raw binary data into strings by using only the first 8 bits of each character. This encoding method is deprecated and should be avoided in favor of Buffer objects where possible. This encoding will be removed in future versions of Node.
Top answer 1 of 8
2832
Buffers can be used for taking a string or piece of data and doing Base64 encoding of the result. For example:
> console.log(Buffer.from("Hello World").toString('base64'));
SGVsbG8gV29ybGQ=
> console.log(Buffer.from("SGVsbG8gV29ybGQ=", 'base64').toString('ascii'))
Hello World
The Buffer constructor is a global object, so no require is needed. Buffers created with strings can take an optional encoding parameter to specify what encoding the string is in. The available toString and Buffer constructor encodings are as follows:
'ascii' - for 7 bit ASCII data only. This encoding method is very fast, and will strip the high bit if set.
'utf8' - Multi byte encoded Unicode characters. Many web pages and other document formats use UTF-8.
'ucs2' - 2-bytes, little endian encoded Unicode characters. It can encode only BMP(Basic Multilingual Plane, U+0000 - U+FFFF).
'base64' - Base64 string encoding.
'binary' - A way of encoding raw binary data into strings by using only the first 8 bits of each character. This encoding method is deprecated and should be avoided in favor of Buffer objects where possible. This encoding will be removed in future versions of Node.
2 of 8
402
The accepted answer previously contained new Buffer(), which is considered a security issue in Node.js versions greater than 6 (although it seems likely for this use case that the input can always be coerced to a string).
The Buffer constructor is deprecated according to the documentation.
The code snippets should read:
console.log(Buffer.from("Hello World").toString('base64'));
console.log(Buffer.from("SGVsbG8gV29ybGQ=", 'base64').toString('ascii'));
After this answer was written, it has been updated and now matches this.
Node.js
nodejs.org › api › buffer.html
Buffer | Node.js v26.10.0 Documentation
import { Buffer } from 'node:buffer'; const buf = Buffer.from('hello world', 'utf8'); console.log(buf.toString('hex')); // Prints: 68656c6c6f20776f726c64 console.log(buf.toString('base64')); // Prints: aGVsbG8gd29ybGQ= console.log(Buffer.from('fhqwhgads', 'utf8')); // Prints: <Buffer 66 68 71 77 68 67 61 64 73> console.log(Buffer.from('fhqwhgads', 'utf16le')); // Prints: <Buffer 66 00 68 00 71 00 77 00 68 00 67 00 61 00 64 00 73 00> const { Buffer } = require('node:buffer'); const buf = Buffer.from('hello world', 'utf8'); console.log(buf.toString('hex')); // Prints: 68656c6c6f20776f726c64 console.log(buf.toString('base64')); // Prints: aGVsbG8gd29ybGQ= console.log(Buffer.from('fhqwhgads', 'utf8')); // Prints: <Buffer 66 68 71 77 68 67 61 64 73> console.log(Buffer.from('fhqwhgads', 'utf16le')); // Prints: <Buffer 66 00 68 00 71 00 77 00 68 00 67 00 61 00 64 00 73 00>
GeeksforGeeks
geeksforgeeks.org › node.js › how-base64-encoding-and-decoding-is-done-in-node-js
How Base64 Encoding and Decoding is Done in Node.js ? - GeeksforGeeks
January 8, 2025 - The Buffer.from() method is again used to convert the base64 string back to bytes, however, this time specifying the current encoding as "base64". The converted bytes can then be returned as the original utf8 string using the toString() method.
Better Stack
betterstack.com › community › questions › how-to-do-base64-encoding-in-node-js
How can I do Base64 encoding in Node.js? | Better Stack Community
March 11, 2024 - In Node.js, you can use the built-in Buffer class to perform Base64 encoding and decoding.
GitHub
github.com › juanelas › base64
juanelas/base64
You can also download the IIFE bundle, the ESM bundle or the UMD bundle and manually add it to your project, or, if you have already installed @juanelas/base64 in your project, just get the bundles from node_modules/@juanelas/base64/dist/bundles/. ...
Author: juanelas
Colbyhemond
colbyhemond.me › blog › encoding-base64
Encoding Base64 with Node.js | Blog
June 13, 2022 - const string = 'this string will be converted to base64' const stringBuffer = Buffer.from(string) const stringBase64 = stringBuffer.toString('base64') // Output: "dGhpcyBzdHJpbmcgd2lsbCBiZSBjb252ZXJ0ZWQgdG8gYmFzZTY0"
DigitalOcean
digitalocean.com › community › tutorials › how-to-encode-and-decode-strings-with-base64-in-javascript
How To Encode and Decode Strings with Base64 in JavaScript | DigitalOcean
Learn how to encode and decode strings with Base64 in JavaScript. This guide covers btoa(), atob(), Buffer, modern APIs, and practical examples.
Stack Abuse
stackabuse.com › encoding-and-decoding-base64-strings-in-node-js
Encoding and Decoding Base64 Strings in Node.js
August 22, 2017 - In the above script, we create a new buffer object and pass it our string that we want to convert to Base64. We then call the toString method on the buffer object that we just created and pass it "base64" as a parameter. The toString method with "base64" as a parameter will return data in the ...
O'Reilly
oreilly.com › library › view › the-javascript-json › 9781785286902 › ch08s02.html
Encoding binary data as a base64 string using Node.js - The JavaScript JSON Cookbook [Book]
June 25, 2015 - var buffer = newBuffer('Hello world'); var string = buffer.toString('base64');
Author: Ray Rischpater
Published: 2015
Pages: 192
Top answer 1 of 2
38
new Buffer(...) has been deprecated for a while now, go for Buffer.from(...)
a simple example might be:
var utf8encoded = Buffer.from(base64encoded, 'base64').toString('utf8');
2 of 2
26
In order to convert from a base64 encoded String to utf8 you can use the following:
var base64encoded = '0KHQvdCw0YfQsNC70LAg0YHQvtC30LTQsNC10YLRgdGPINGA0LXRiNC10YLQutCwINC/0YDQvtGB 0YLRgNCw0L3RgdGC0LLQsCDQstC+0L7QsdGA0LDQttC10L3QuNGPLiZuYnNwOzxkaXY+PGJyPjwv ZGl2PjxkaXY+0JfQsNGC0LXQvCDQvdCwI';
var utf8encoded = (new Buffer(base64encoded, 'base64')).toString('utf8');
Codemia
codemia.io › home › knowledge hub › how can i do base64 encoding in node.js?
How can I do Base64 encoding in Node.js? | Codemia
January 2, 2025 - Encode binary content directly from buffers, not through intermediate text conversions. Use base64url when the output is meant for URLs or compact tokens.
Medium
smali-kazmi.medium.com › base64-encoding-decoding-in-node-js-eb072b7a96e3
base64 encoding & decoding in node.js - Mudaser Ali - Medium
February 24, 2021 - Nodejs · JavaScript · Encoding Decoding · Mudaser Ali · Feb 24, 2021 · -- Listen · Share · To encode string into base64 · var string = “Some random string for base64” · var buff = Buffer.from(string, ‘utf-8’) var encoding = buff.toString(‘base64’) console.log(encoding) //U29tZSByYW5kb20gc3RyaW5nIGZvciBiYXNlNjQ= To decode base64 string ·
Top answer 1 of 2
13
You can create a readable stream and push the image buffer. Then pipe it to a writeable stream like this.
var base64 = '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';
var fs = require('fs')
var Readable = require('stream').Readable
const imgBuffer = Buffer.from(base64, 'base64')
var s = new Readable()
s.push(imgBuffer)
s.push(null)
s.pipe(fs.createWriteStream("test.png"));
2 of 2
1
Just another solution with base-64 & utf8 in case we're using react-native which doesn't have Buffer global object:
function (base64Str) {
return utf8.decode(base64.decode(base64Str))
}
Salrahman
notes.salrahman.com › base64-to-buffer-nodejs
Base64 string to Node.js Buffer (Node.js 6+) · Notes on code. My second brain, by Sal Rahman.
Base64 string to Node.js Buffer (Node.js 6+) · JavaScriptNode.js · It's just: · const buf = Buffer.from(b64string, "base64"); · Edit this page · Want to make your own site like this? Try gatsby-theme-code-notes by Zander Martineau · Notes on code. My second brain, by Sal Rahman
Stack Abuse
stackabuse.com › bytes › converting-images-and-image-urls-to-base64-in-node-js
Converting Images and Image URLs to Base64 in Node.js
August 19, 2023 - In Node.js, converting an image URL to Base64 can be achieved using the request module along with the built-in Buffer class.
Top answer 1 of 3
47
fs.readFile(attachment, function(err, data) {
var base64data = new Buffer(data).toString('base64');
[your API call here]
});
It takes some time until the results are there, so by the time you've got the data, the outer scopes execution is already over.
2 of 3
13
Just specify "base64" as the encoding. Per the docs:
If no encoding is specified, then the raw buffer is returned.
fs.readFile(attachment, {encoding: 'base64'}, function(err, base64data) {
[your API call here]
});
Base64Encode.org
base64encode.org › enc › node
Base64 Encoding of "node" - Online
Base64 encoding schemes are commonly used when there is a need to encode binary data, especially when that data needs to be stored and transferred over media that are designed to deal with text. This encoding helps to ensure that the data remains intact without modification during transport.
CodeForGeek
codeforgeek.com › base64-encoding-decoding-nodejs
How to Encode and Decode Base64 Strings in Node.js | CodeForGeek
August 30, 2024 - We can use the Buffer class from this module with the toString() method and generate our Base64 encoded string.
GeeksforGeeks
geeksforgeeks.org › convert-base64-string-to-arraybuffer-in-javascript
Convert base64 String to ArrayBuffer In JavaScript | GeeksforGeeks
September 13, 2024 - A Base64 string represents binary data in an ASCII string format by translating it into a radix-64 representation. Often used to encode binary data in text-based formats like JSON or HTML, it needs to be converted back into its original binary format for further processing. An ArrayBuffer in JavaScript is a generic, fixed-length binary data buffer, which is useful when working with raw binary data such as images or files.
Stack Overflow
stackoverflow.com › q › 26099288
Buffer base64 encode a variable, node.js
September 29, 2014 - I am trying to encode a variable from a http parameter to base64 using node.js and buffer. My code: var http = require("http"); var url = require("url"); http.createServer(function(req, res) { ...