Chrome DevTools Tricks

// atob(): decodes a Base64-encoded string ("atob" should be read as "ASCII to binary").

atob('SGVsbG8gd29ybGQh') > 'Hello world!'

// btoa(): creates a Base64-encoded ASCII string from a "string" of binary data ("btoa" should be read as "binary to ASCII").

btoa('Hello world!') > 'SGVsbG8gd29ybGQh'

const encodedData = btoa('Hello, world') // encode a string
const decodedData = atob(encodedData) // decode the string

function utf8_to_b64(str) {
  return window.btoa(unescape(encodeURIComponent(str)))
}

function b64_to_utf8(str) {
  return decodeURIComponent(escape(window.atob(str)))
}

// Usage:
utf8_to_b64('Hello world !') // "SGVsbG8gd29ybGQgIQ=="
b64_to_utf8('SGVsbG8gd29ybGQgIQ==') // "Hello world !"