FileReader: readyState property

Note: This feature is available in Web Workers.

The readyState read-only property of the FileReader interface provides the current state of the reading operation. This will be one of the states: EMPTY, LOADING, or DONE.

Value

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

FileReader.EMPTY

Reader has been created, but none of the read methods have been called yet.

FileReader.LOADING

A read method has been called. A File or Blob is being read, and no error has occurred yet.

FileReader.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
};

Specifications

Specification
File API
# dom-filereader-readystate

Browser compatibility

BCD tables only load in the browser

See also