Non-standard
 
      This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
  Obsolete
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
The Navigator.mozIsLocallyAvailable() method allows add-ons to determine whether or not a given resource is available.
Note: Security exceptions can occur if the requested URI is not from the same origin.
Syntax
navigator.mozIsLocallyAvailable(uri, ifOffline);
Parameters
- uri
- The URI of the resource whose availability is to be checked, as a string.
- ifOffline
- 
 Allows you to specify whether or not the offline resources cache should be checked; specify trueto consider the offline resources cache.
Example
var available = navigator.mozIsLocallyAvailable("my-image-file.png", true);
if (available) {
  /* the offline resource is present */
} else {
  console.log("Certain needed resources are not available offline");
}
Specifications
Not part of any specifications.
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari | 
|---|---|---|---|---|---|
| Basic support | No support | (Yes) Removed in 35 (35) | No support | No support | No support | 
| Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile | 
|---|---|---|---|---|---|---|
| Basic support | No support | No support | (Yes) Removed in 35.0 (35) | No support | No support | No support | 
Document Tags and Contributors
    
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                       Contributors to this page: 
        teoli, 
        Sebastianz, 
        fscholz, 
        MHasan, 
        kscarfone, 
        iamanupmenon, 
        Sheppy, 
        ziyunfei, 
        Mgjbot, 
        Waldo
                    
                    
                       Last updated by:
                      Sebastianz,