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Response.ok

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The ok read-only property of the Response interface contains a boolean stating whether the response was successful (status in the range 200-299) or not.

Syntax

var myOK = response.ok;

Value

A Boolean.

Example

In our Fetch Response example (see Fetch Response live) we create a new Request object using the Request() constructor, passing it a JPG path. We then fetch this request using fetch(), extract a blob from the response using Body.blob, create an object URL out of it using URL.createObjectURL, and display this in an <img>.

Note that at the top of the fetch() block we log the response ok value to the console.

var myImage = document.querySelector('img');

var myRequest = new Request('flowers.jpg');

fetch(myRequest).then(function(response) {
  console.log(response.ok); // returns true if the response returned successfully
  response.blob().then(function(myBlob) {
    var objectURL = URL.createObjectURL(myBlob);
    myImage.src = objectURL;
  });
});

Specifications

Specification Status Comment
Fetch
The definition of 'ok' in that specification.
Living Standard Initial definition

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 42
41[1]
(Yes) 39 (39)
34[1]
No support

29
28[1]

No support
Feature Android Edge Firefox Mobile (Gecko) Firefox OS (Gecko) IE Phone Opera Mobile Safari Mobile Chrome for Android
Basic support No support (Yes) No support No support No support No support No support No support

[1] This feature is implemented behind a preference.

See also

© 2005–2017 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/Response/ok