This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for the proper prefixes to use 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 spec 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 | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|
| Basic support | 42 41[1] |
39 (39) 34[1] |
Not supported |
29 |
Not supported |
| Feature | Android | Firefox Mobile (Gecko) | Firefox OS (Gecko) | IE Phone | Opera Mobile | Safari Mobile | Chrome for Android |
|---|---|---|---|---|---|---|---|
| Basic support | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported | Not supported |
[1] This feature is implemented behind a preference.