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 client-side javascript but for some reason weren't included in node. The new directory showed up in my node_modules folder, which itself is in root alongside app.js. Then I made sure to add btoa-atob as a dependency in my package.json file which is in root.

However, for some reason, it still will not work.

console.log(btoa("Hello World!")); 

^ should output "SGVsbG8gV29ybGQh" to the console, but instead, I get the error:

btoa is not defined.

Did I not do the install properly? What did I overlook?

Answer 1

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()); 

---

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

Answer 2

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: