WindowOrWorkerGlobalScope.atob()
The WindowOrWorkerGlobalScope.atob() function decodes a
string of data which has been encoded using Base64 encoding. You can use
the btoa() method to encode and transmit
data which may otherwise cause communication problems, then transmit it and use the
atob() method to decode the data again. For example, you can encode,
transmit, and decode control characters such as ASCII values 0 through 31.
For use with Unicode or UTF-8 strings, see the note on "Unicode strings" in the page
for btoa().
Syntax
var decodedData = scope.atob(encodedData);Parameters
encodedData- A binary string contains an base64 encoded data.
Return value
An ASCII string containing decoded data from encodedData.
Exceptions
DOMException(name:InvalidCharacterError)- Throws if
encodedDatais not valid base64.
Example
const encodedData = window.btoa('Hello, world'); // encode a string
const decodedData = window.atob(encodedData); // decode the stringPolyfill
You can use a polifill from https://github.com/MaxArt2501/base64-js/blob/master/base64.js for browsers that don't support it.
Specifications
| Specification | Status | Comment |
|---|---|---|
| HTML Living Standard The definition of 'WindowOrWorkerGlobalScope.atob()' in that specification. |
Living Standard | Method moved to the WindowOrWorkerGlobalScope mixin in the latest
spec. |
| HTML 5.1 The definition of 'WindowBase64.atob()' in that specification. |
Recommendation | Snapshot of HTML Living Standard. No change. |
| HTML5 The definition of 'WindowBase64.atob()' in that specification. |
Recommendation | Snapshot of HTML Living Standard. Creation of WindowBase64
(properties where on the target before it). |
Browser compatibility
BCD tables only load in the browser