Node.js throws “btoa is not defined” error

Question

In my node.js application I did an npm install btoa-atob so that I could use the btoa() and atob() functions which are native in clien

Answer 1

Here's a concise universal solution for base64 encoding:

const nodeBtoa = (b) => Buffer.from(b).toString('base64');
export const base64encode = typeof btoa !== 'undefined' ? btoa : nodeBtoa;

Answer 2

Maybe you don't need it anymore but if someone needs this using node: https://www.npmjs.com/package/btoa

Answer 3

The 'btoa-atob' module does not export a programmatic interface, it only provides command line utilities.

If you need to convert to Base64 you could do so using Buffer:

console.log(Buffer.from('Hello World!').toString('base64'));

Reverse (assuming the content you're decoding is a utf8 string):

console.log(Buffer.from(b64Encoded, 'base64').toString());

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Note: prior to Node v4, use new Buffer rather than Buffer.from.

Answer 4

The solutions posted here don't work in non-ascii characters (i.e. if you plan to exchange base64 between Node.js and a browser). In order to make it work you have to mark the input text as 'binary'.

Buffer.from('Hélló wórld!!', 'binary').toString('base64')

This gives you SOlsbPMgd/NybGQhIQ==. If you make atob('SOlsbPMgd/NybGQhIQ==') in a browser it will decode it in the right way. It will do it right also in Node.js via:

Buffer.from('SOlsbPMgd/NybGQhIQ==', 'base64').toString('binary')

If you don't do the "binary part", you will decode wrongly the special chars.

I got it from the implementation of the btoa npm package: