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Encoding and decoding a string in Base64 with JavaScript can be quite handy.
For that we have the btoa() and atob() functions. These two base64 helper functions are a core part of the HTML spec and available in all modern browsers.
btoa()encodes to Base64atob()decodes from Base64
// Define the string
var string = 'Hello World!';
// Encode the String
var encodedString = btoa(string);
console.log(encodedString); // Outputs: "SGVsbG8gV29ybGQh"
// Decode the String
var decodedString = atob(encodedString);
console.log(decodedString); // Outputs: "Hello World!"
Copy and paste the examples above in your Chrome Console to see them working.
Common use cases for Base64
- Packaging things like form input and JSON strings into a character set that’s safer to use in HTTP requests
- Representing binary data in a way that’s compatible with HTML/JavaScript/CSS. – You can embed an image inline in a CSS or JavaScript file using Base64, for example.
What Base64 is not:
- It’s in no way meant to be a secure encryption method,
- It’s not a compression method, encoding a string to Base64 typically results in ~33% longer output.