function _arrayBufferToBase64( buffer ) {
var binary = '';
var bytes = new Uint8Array( buffer );
var len = bytes.byteLength;
for (var i = 0; i < len; i++) {
binary += String.fromCharCode( bytes[ i ] );
}
return window.btoa( binary );
}
but, non-native implementations are faster e.g. https://gist.github.com/958841 see http://jsperf.com/encoding-xhr-image-data/6
jsPerf.com is jsPerf.app now: https://jsperf.app/encoding-xhr-image-data/51
Updated benchmarks: https://jsben.ch/wnaZC
Answer from mobz on Stack OverflowMDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › Uint8Array › toBase64
Uint8Array.prototype.toBase64() - JavaScript - MDN Web Docs
The toBase64() method of Uint8Array instances returns a base64-encoded string based on the data in this Uint8Array object.
MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › Uint8Array › fromBase64
Uint8Array.fromBase64() - JavaScript - MDN Web Docs
Accept input encoded with the standard base64 alphabet, which uses + and /.
Top answer 1 of 16
378
function _arrayBufferToBase64( buffer ) {
var binary = '';
var bytes = new Uint8Array( buffer );
var len = bytes.byteLength;
for (var i = 0; i < len; i++) {
binary += String.fromCharCode( bytes[ i ] );
}
return window.btoa( binary );
}
but, non-native implementations are faster e.g. https://gist.github.com/958841 see http://jsperf.com/encoding-xhr-image-data/6
jsPerf.com is jsPerf.app now: https://jsperf.app/encoding-xhr-image-data/51
Updated benchmarks: https://jsben.ch/wnaZC
2 of 16
208
This works fine for me:
var base64String = btoa(String.fromCharCode.apply(null, new Uint8Array(arrayBuffer)));
In ES6, the syntax is a little simpler:
const base64String = btoa(String.fromCharCode(...new Uint8Array(arrayBuffer)));
As pointed out in the comments, this method may result in a runtime error in some browsers when the ArrayBuffer is large. The exact size limit is implementation dependent in any case.
GitHub
gist.github.com › jonleighton › 958841
Encode an ArrayBuffer as a base64 string · GitHub
@Teamop this way wont work for ArrayBuffer larger than 30k bytes. While this thread was about "Converts an ArrayBuffer directly to base64, without any intermediate 'convert to string then use window.btoa' step" so I'm going a bit off topic, but there is a way to avoid the "larger than 30k bytes" issues using reduce.
EyeHunts
tutorial.eyehunts.com › home › byte array to base64 javascript | examples code
Byte Array to Base64 JavaScript | Simple Examples code
December 9, 2021 - Convert received arrayBuffer value into Base64 encoded string and then we write a file using toBinary() function of CFML bypassing Base64 encoded string in it. Below is custom JavaScript function arrayBufferToBase64() to accomplish the requirement.
npm
npmjs.com › package › byte-base64
byte-base64 - npm
August 18, 2020 - In particular, atob and btoa only support ASCII strings. ... bytesToBase64(bytes: number[] | Uint8Array): string - Encodes a Uint8Array or JS array of bytes to a base64-encoded string.
» npm install byte-base64
Published Aug 18, 2020
Version 1.1.0
GitHub
gist.github.com › llzes › 24fe0a9b3d786d48f2b3932a633d5b2b
Byte to Base64 implementation in JavaScript · GitHub
Byte to Base64 implementation in JavaScript. GitHub Gist: instantly share code, notes, and snippets.
Isummation
isummation.com › home › development › convert arraybuffer to base64 string and vice-versa
JavaScript - Convert arrayBuffer to Base64 string and vice-versa iSummation - USA
August 30, 2019 - Here first we need to convert received arrayBuffer value into Base64 encoded string and then we write a file using toBinary() function of CFML by passing Base64 encoded string in it.
GitHub
gist.github.com › Deliaz › e89e9a014fea1ec47657d1aac3baa83c
Convert array buffer to base64 string · GitHub
Convert array buffer to base64 string. GitHub Gist: instantly share code, notes, and snippets.
IQCode
iqcode.com › code › javascript › convert-base64-string-to-byte-array-javascript
convert base64 string to byte array javascript Code Example
November 4, 2021 - javascript base64 encode byte array bytearray to base64 js byte array to base64 in javascript byte to base64 javascript javascript bytes to base64 nodejs base64 to byte array base64 to byte array js js string to byte array and base64 encode convert byte to base64 string javascript js base64 encode byte array convert byte array to base64 string js from byte base64 to base64 javascript array byte to base64 js javascript array of bytes to base64 node js base64 to byte array javascript byte array to base64 convert 2048 to byte array using base64 decoder javascript convert string to byte array usin
Grafana
community.grafana.com › grafana k6 › oss support
Base64 encode ArrayBuffer - OSS Support - Grafana Labs Community Forums
December 7, 2020 - I have a set of bytes in an ArrayBuffer. I need to base64 encode this in k6. How do I accomplish this? In node.js it is data.toString(‘base64’) in browsers the btoa() function seems to be the way to go. Neither of the…
Top answer 1 of 14
289
function base64ToArrayBuffer(base64) {
var binaryString = atob(base64);
var bytes = new Uint8Array(binaryString.length);
for (var i = 0; i < binaryString.length; i++) {
bytes[i] = binaryString.charCodeAt(i);
}
return bytes.buffer;
}
2 of 14
177
Using TypedArray.from:
Uint8Array.from(atob(base64_string), c => c.charCodeAt(0))
Performance to be compared with the for loop version of Goran.it answer.
Stack Overflow
stackoverflow.com › questions › 24761778 › javascript-encode-byte-array-to-base64
encoding - Javascript : Encode byte [ ] array to base64 - Stack Overflow
Now I would like to encode bytes[ ] to base64 format. Is there a library to do that? I will appreciate your help! ... Thanks, but they don't seem to work with byte[ ] . ... Save this answer. ... Show activity on this post. btoa and atob work with strings, which they treat as arrays of bytes, so to use these two functions, you should first convert your array of integers (provided they fall in the range 0-255) into a string.
GeeksforGeeks
geeksforgeeks.org › javascript › how-to-convert-byte-array-to-string-in-javascript
JavaScript - Convert Byte Array to String - GeeksforGeeks
July 23, 2025 - This approach involves encoding the byte array into Base64 and decoding it to a string.
Stack Overflow
stackoverflow.com › questions › 60730932 › how-to-convert-byte-array-to-base64
javascript - How to convert byte array to base64 - Stack Overflow
In this post (Creating a Blob from a base64 string in JavaScript) they take base64 and convert to a byte array. I haven't been able to figure out how to convert byte array back in to base64 code. I
Linode
linode.com › docs › guides › javascript-base-64-decode
How to Use JavaScript Base 64 to Decode and Encode | Linode Docs
March 29, 2023 - It then translates these values into the Base64 set of printable characters. Developers can encode strings into Base64 in JavaScript using the btoa function. The atob function can decode the Base64 string back to its original format.
npm
npmjs.com › package › base64-js
base64-js - npm
November 11, 2020 - base64js has three exposed functions, byteLength, toByteArray and fromByteArray, which both take a single argument. byteLength - Takes a base64 string and returns length of byte array
» npm install base64-js
Published Nov 11, 2020
Version 1.5.1
GeeksforGeeks
geeksforgeeks.org › how-to-convert-byte-array-to-string-in-javascript
JavaScript – Convert Byte Array to String | GeeksforGeeks
November 26, 2024 - This is because characters ... NPM(Node Package Manager) is a package manager of Node.js packages. There is an NPM package called arraybuffer-to-string used to decode array buffers in actual strings.
Top answer 1 of 4
276
function base64ToArrayBuffer(base64) {
var binaryString = atob(base64);
var bytes = new Uint8Array(binaryString.length);
for (var i = 0; i < binaryString.length; i++) {
bytes[i] = binaryString.charCodeAt(i);
}
return bytes.buffer;
}
2 of 4
165
Using TypedArray.from:
Uint8Array.from(atob(base64_string), c => c.charCodeAt(0))
Performance to be compared with the for loop version of Goran.it answer.