#Javascript base64 decode how to

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

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

In JavaScript there are two functions respectively for decoding and encoding Base64 strings: One common application of Base64 encoding on the web is to encode binary data so it can be included in a data: URL. Base64 is commonly used in a number of applications including email via MIME, and storing complex data in XML. This is to ensure that the data remain intact without modification during transport. The term Base64 originates from a specific MIME content transfer encoding.īase64 encoding schemes are commonly used when there is a need to encode binary data that needs to be stored and transferred over media that are designed to deal with ASCII. On the other hand, the ASCII character set is quite simple to consume for most applications.įor more information on Base64 encoding and decoding, read this MDN guide.Base64 is a group of similar binary-to-text encoding schemes that represent binary data in an ASCII string format by translating it into a radix-64 representation. But it can be risky sometimes, as not all applications and network communication devices can handle raw binary data. Of course, you can still choose to send binary data over the network. Base64 is a widely used encoding scheme for securely transmitting binary data as a stream of ASCII characters over the network. That's all folks for Base64 encoding and decoding in JavaScript. There are 1367 other projects in the npm registry using base-64. Start using base-64 in your project by running npm i base-64. Latest version: 1.0.0, last published: 2 years ago. To encode Unicode characters, you first need to escape the input string to an array of 8-bit bytes (like UTF-8) and then use btoa() to encode it to Base64, as shown in the following example: function encodeUnicode ( str ) decodeUnicode ( 'SmF2YVNjcmlwdCBpcyBmdW4g8J+OiQ=' ) // JavaScript is fun 🎉 decodeUnicode ( '8J+UpfCfkqE=' ) // 🔥💡 Conclusion A robust base64 encoder/decoder that is fully compatible with atob() and btoa(), written in JavaScript. If you execute the above code, you should see the following error output: Uncaught DOMException: Failed to execute 'btoa' on 'Window' : The string to be encoded contains characters outside of the Latin1 range. Here is an example: const str = 'JavaScript is fun 🎉' // encode the string const encodedStr = btoa (str ) // print encoded string If your input data contains any character with more than 8 bits, for instance, a Unicode character, the btoa() function will throw an exception. log (encodedStr ) // output: SmF2YVNjcmlwdCBpcyBmdW4hIQ=īy default, the btoa() method works fine for binary data consisting of 8-bit bytes.

The following example shows how you can use btoa() to Base64 encode a string in JavaScript: const str = 'JavaScript is fun!!' // encode the string const encodedStr = btoa (str ) // print encoded stringĬonsole. It accepts the binary string as an argument and returns a Base64 encoded ASCII string. The btoa() function (stands for binary-to-ASCII) is used to create a Base64 encoded ASCII string from the binary data. There are two built-in functions in JavaScript for encoding and decoding raw binary data into Base64 strings.

#Javascript base64 decode how to

In this article, you'll learn how to encode and decode Base64 strings in JavaScript. You first encode the binary file into a textual format, preferably ASCII. It only transforms the binary data into an ASCII character set that is extremely useful for transferring obfuscated strings over the network.įor instance, a simple example is sending an image or any other binary file to an email server that typically expects textual data. To convert Base64 to original data, JavaScript provides the atob function which is an acronym for ASCII to Binary. It is important to remember that Base64 is not an encryption or compression scheme. Base64 makes sure that the binary data doesn't change during transportation. It is commonly used for encoding and transporting data over media incompatible with transferring binary data. Base64 is a widely used binary-to-text encoding scheme that transforms binary data into an equivalent ASCII character set by translating it into a radix-64 representation.