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FileReader: readyState property

The FileReader readyState property provides the current state of the reading operation a FileReader is in. A FileReader exists in one of the following states:

Value State Description
0 EMPTY Reader has been created. None of the read methods called yet.
1 LOADING A read method has been called.
2 DONE The operation is complete.
EMPTY

The FileReader has been created, but no readAs method was called yet.

LOADING

A readAs method was invoked. A File or Blob is being read, and no error has occurred yet.

DONE

The read operation is complete. This could mean that: the entire File or Blob has been read into memory, a file read error occurred, or abort() was called and the read was cancelled.

Examples

js

const reader = new FileReader();
console.log("EMPTY", reader.readyState); // readyState will be 0

reader.readAsText(blob);
console.log("LOADING", reader.readyState); // readyState will be 1

reader.onloadend = () => {
  console.log("DONE", reader.readyState); // readyState will be 2
};

Value

A number which is one of the three possible state constants define for the FileReader API.

Specifications

Specification
File API
# dom-filereader-readystate

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
readyState 6 12 3.6 10 11 6 3 18 32 11 6 1.0

See also

© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/FileReader/readyState