Document.readyState

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

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

Syntax

let string = document.readyState;

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 scripts, 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.

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.
    // But sub-resources such as scripts, images, stylesheets and frames are still loading.
    const 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

document.addEventListener('readystatechange', event => {
  if (event.target.readyState === 'interactive') {
    initLoader();
  }
  else if (event.target.readyState === 'complete') {
    initApp();
  }
});

Specifications

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
1
12
3.6
11
9-11
Internet Explorer 9 and 10 have bugs where the 'interactive' state can be fired too early before the document has finished parsing.
4-9
Only supports 'complete'.
11
Opera Presto fires 'complete' late after the 'load' event (in an incorrect order as per HTML5 standard specification).
1
1
18
4
11
Opera Presto fires 'complete' late after the 'load' event (in an incorrect order as per HTML5 standard specification).
1
1.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/Document/readyState