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document.readyState

The Document.readyState property of a document describes the loading state of the document.

Values

The readyState of a document can be one of following:

loading
The document is still loading.
interactive
The document has finished loading and the document has been parsed but sub-resources such as images, stylesheets and frames are still loading.
complete
The document and all sub-resources have finished loading. The state indicates that the load event is about to fire.

When the value of this property changes a readystatechange event fires on the document object.

Syntax

var string = document.readyState;

Examples

Different states of readiness

switch (document.readyState) {
  case "loading":
    // The document is still loading.
    break;
  case "interactive":
    // The document has finished loading. We can now access the DOM elements.
    var span = document.createElement("span");
    span.textContent = "A <span> element.";
    document.body.appendChild(span);
    break;
  case "complete":
    // The page is fully loaded.
    console.log("The first CSS rule is: " + document.styleSheets[0].cssRules[0].cssText);
    break;
}

readystatechange as an alternative to DOMContentLoaded event

// alternative to DOMContentLoaded event
document.onreadystatechange = function () {
  if (document.readyState === "interactive") {
    initApplication();
  }
}

readystatechange as an alternative to load event

// alternative to load event
document.onreadystatechange = function () {
  if (document.readyState === "complete") {
    initApplication();
  }
}

readystatechange as event listener to insert or modify the DOM before DOMContentLoaded

// early manipulation of the document <body> using an external script
var bootstrap = function(evt){
  if (evt.target.readyState === "interactive") { initLoader(); }
  else if (evt.target.readyState === "complete") { initApp(); }
} 
document.addEventListener('readystatechange', bootstrap, false);

Specification

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support 5.0 (Yes) 4.0 4.0[3]8.0[1] 9.0[2] 11.0[1] 5.0
Feature Android Edge Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support 2.2 (Yes) 4.0 9[2] 11.0[1] 5.0

[1] Only support 'complete'. Opera Presto fire 'complete' late after the 'load' event (in an incorrect order as per HTML5 standard specification).

[2] Internet Explorer 9 and 10 have bugs where the 'interactive' state can be fired too early before the document has finished parsing.

[3] When introduced with IE 4, the property was available for only the document, embed, img, link, object, script, and style objects. IE 5 expanded coverage to all HTML element objects.

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/document/readyState