html5 localStorage error with Safari: "QUOTA_EXCEEDED_ERR: DOM Exception 22: An attempt was made to add something to storage that exceeded the quota."

My webapp have javascript errors in ios safari private browsing:

> JavaScript:error > > undefined > > QUOTA_EXCEEDED_ERR:DOM Exception 22:An attempt was made to add something to storage...

my code:

localStorage.setItem('test',1)

Apparently this is by design. When Safari (OS X or iOS) is in private browsing mode, it appears as though localStorage is available, but trying to call setItem throws an exception.

store.js line 73
"QUOTA_EXCEEDED_ERR: DOM Exception 22: An attempt was made to add something to storage that exceeded the quota."

What happens is that the window object still exposes localStorage in the global namespace, but when you call setItem, this exception is thrown. Any calls to removeItem are ignored.

I believe the simplest fix (although I haven't tested this cross browser yet) would be to alter the function isLocalStorageNameSupported() to test that you can also set some value.

https://github.com/marcuswestin/store.js/issues/42

function isLocalStorageNameSupported() 
{
    var testKey = 'test', storage = window.sessionStorage;
    try 
    {
        storage.setItem(testKey, '1');
        storage.removeItem(testKey);
        return localStorageName in win && win[localStorageName];
    } 
    catch (error) 
    {
        return false;
    }
}

The fix posted on above link did not work for me. This did:

function isLocalStorageNameSupported() {
  var testKey = 'test', storage = window.localStorage;
  try {
    storage.setItem(testKey, '1');
    storage.removeItem(testKey);
    return true;
  } catch (error) {
    return false;
  }
}

Derived from http://m.cg/post/13095478393/detect-private-browsing-mode-in-mobile-safari-on-ios5

As mentioned in other answers, you'll always get the QuotaExceededError in Safari Private Browser Mode on both iOS and OS X when localStorage.setItem (or sessionStorage.setItem) is called.

One solution is to do a try/catch or Modernizr check in each instance of using setItem.

However if you want a shim that simply globally stops this error being thrown, to prevent the rest of your JavaScript from breaking, you can use this:

https://gist.github.com/philfreo/68ea3cd980d72383c951

// Safari, in Private Browsing Mode, looks like it supports localStorage but all calls to setItem
// throw QuotaExceededError. We're going to detect this and just silently drop any calls to setItem
// to avoid the entire page breaking, without having to do a check at each usage of Storage.
if (typeof localStorage === 'object') {
    try {
        localStorage.setItem('localStorage', 1);
        localStorage.removeItem('localStorage');
    } catch (e) {
        Storage.prototype._setItem = Storage.prototype.setItem;
        Storage.prototype.setItem = function() {};
        alert('Your web browser does not support storing settings locally. In Safari, the most common cause of this is using "Private Browsing Mode". Some settings may not save or some features may not work properly for you.');
    }
}

In my context, just developed a class abstraction. When my application is launched, i check if localStorage is working by calling getStorage(). This function also return :

• either localStorage if localStorage is working
• or an implementation of a custom class LocalStorageAlternative

In my code i never call localStorage directly. I call cusStoglobal var, i had initialised by calling getStorage().

This way, it works with private browsing or specific Safari versions

function getStorage() {
    
    var storageImpl;

     try { 
        localStorage.setItem("storage", ""); 
        localStorage.removeItem("storage");
        storageImpl = localStorage;
     }
     catch (err) { 
         storageImpl = new LocalStorageAlternative();
     }

    return storageImpl;

}

function LocalStorageAlternative() {

    var structureLocalStorage = {};

    this.setItem = function (key, value) {
        structureLocalStorage[key] = value;
    }

    this.getItem = function (key) {
        if(typeof structureLocalStorage[key] != 'undefined' ) {
            return structureLocalStorage[key];
        }
        else {
            return null;
        }
    }

    this.removeItem = function (key) {
        structureLocalStorage[key] = undefined;
    }
}

cusSto = getStorage();

It seems that Safari 11 changes the behavior, and now local storage works in a private browser window. Hooray!

Our web app that used to fail in Safari private browsing now works flawlessly. It always worked fine in Chrome's private browsing mode, which has always allowed writing to local storage.

This is documented in Apple's Safari Technology Preview release notes - and the WebKit release notes - for release 29, which was in May 2017.

Specifically:

• Fixed QuotaExceededError when saving to localStorage in private browsing mode or WebDriver sessions - r215315

To expand on others' answers, here is a compact solution that doesn't expose/add any new variables. It doesn't cover all bases, but it should suit most people who just want a single page app to remain functional (despite no data persistence after reload).

(function(){
    try {
        localStorage.setItem('_storage_test', 'test');
        localStorage.removeItem('_storage_test');
    } catch (exc){
        var tmp_storage = {};
        var p = '__unique__';  // Prefix all keys to avoid matching built-ins
        Storage.prototype.setItem = function(k, v){
            tmp_storage[p + k] = v;
        };
        Storage.prototype.getItem = function(k){
            return tmp_storage[p + k] === undefined ? null : tmp_storage[p + k];
        };
        Storage.prototype.removeItem = function(k){
            delete tmp_storage[p + k];
        };
        Storage.prototype.clear = function(){
            tmp_storage = {};
        };
    }
})();

I had the same problem using Ionic framework (Angular + Cordova). I know this not solve the problem, but it's the code for Angular Apps based on the answers above. You will have a ephemeral solution for localStorage on iOS version of Safari.

Here is the code:

angular.module('myApp.factories', [])
.factory('$fakeStorage', [
	function(){
		function FakeStorage() {};
		FakeStorage.prototype.setItem = function (key, value) {
			this[key] = value;
		};
		FakeStorage.prototype.getItem = function (key) {
			return typeof this[key] == 'undefined' ? null : this[key];
		}
		FakeStorage.prototype.removeItem = function (key) {
			this[key] = undefined;
		};
		FakeStorage.prototype.clear = function(){
			for (var key in this) {
				if( this.hasOwnProperty(key) )
				{
					this.removeItem(key);
				}
			}
		};
		FakeStorage.prototype.key = function(index){
			return Object.keys(this)[index];
		};
		return new FakeStorage();
	}
])
.factory('$localstorage', [
	'$window', '$fakeStorage',
	function($window, $fakeStorage) {
		function isStorageSupported(storageName) 
		{
			var testKey = 'test',
				storage = $window[storageName];
			try
			{
				storage.setItem(testKey, '1');
				storage.removeItem(testKey);
				return true;
			} 
			catch (error) 
			{
				return false;
			}
		}
		var storage = isStorageSupported('localStorage') ? $window.localStorage : $fakeStorage;
		return {
			set: function(key, value) {
				storage.setItem(key, value);
			},
			get: function(key, defaultValue) {
				return storage.getItem(key) || defaultValue;
			},
			setObject: function(key, value) {
				storage.setItem(key, JSON.stringify(value));
			},
			getObject: function(key) {
				return JSON.parse(storage.getItem(key) || '{}');
			},
			remove: function(key){
				storage.removeItem(key);
			},
			clear: function() {
				storage.clear();
			},
			key: function(index){
				storage.key(index);
			}
		}
	}
]);

Source: https://gist.github.com/jorgecasar/61fda6590dc2bb17e871

Enjoy your coding!

Here's a solution for AngularJS using an IIFE and leveraging the fact that services are singletons.

This results in isLocalStorageAvailable being set immediately when the service is first injected and avoids needlessly running the check every time local storage needs to be accessed.

angular.module('app.auth.services', []).service('Session', ['$log', '$window',
  function Session($log, $window) {
    var isLocalStorageAvailable = (function() {
      try {
        $window.localStorage.world = 'hello';
        delete $window.localStorage.world;
        return true;
      } catch (ex) {
        return false;
      }
    })();

    this.store = function(key, value) {
      if (isLocalStorageAvailable) {
        $window.localStorage[key] = value;
      } else {
        $log.warn('Local Storage is not available');
      }
    };
  }
]);

The accepted answer seems not adequate in several situations.

To check whether the localStorage or sessionStorage are supported, I use the following snippet from MDN.

function storageAvailable(type) {
    var storage;
    try {
        storage = window[type];
        var x = '__storage_test__';
        storage.setItem(x, x);
        storage.removeItem(x);
        return true;
    }
    catch(e) {
        return e instanceof DOMException && (
            // everything except Firefox
            e.code === 22 ||
            // Firefox
            e.code === 1014 ||
            // test name field too, because code might not be present
            // everything except Firefox
            e.name === 'QuotaExceededError' ||
            // Firefox
            e.name === 'NS_ERROR_DOM_QUOTA_REACHED') &&
            // acknowledge QuotaExceededError only if there's something already stored
            (storage && storage.length !== 0);
    }
}

Use this snippet like this, and fallback to, for example, using cookie:

if (storageAvailable('localStorage')) {
  // Yippee! We can use localStorage awesomeness
}
else {
  // Too bad, no localStorage for us
  document.cookie = key + "=" + encodeURIComponent(value) + expires + "; path=/";
}

I have made the fallbackstorage package which uses this snippet to check for the storage availability and fallback to a manually implemented MemoryStorage.

import {getSafeStorage} from 'fallbackstorage'

getSafeStorage().setItem('test', '1') // always work

I just created this repo to provide sessionStorage and localStorage features for unsupported or disabled browsers.

Supported browsers

• IE5+
• Chrome all versions
• Mozilla all versions
• Yandex all versions

How it works

It detects the feature with the storage type.

function(type) {
    var testKey = '__isSupported',
        storage = window[type];
    try {
        storage.setItem(testKey, '1');
        storage.removeItem(testKey);
        return true;
    } catch (error) {
        return false;
    }
};

Sets StorageService.localStorage to window.localStorage if it is supported or creates a cookie storage. Sets StorageService.sessionStorage to window.sessionStorage if it is supported or creates a in memory storage for SPA, cookie storage with sesion features for non SPA.

Here is an Angular2+ service version for memory storage alternative, you can just inject into your components, based on Pierre Le Roux' answer.

import { Injectable } from '@angular/core';

// Alternative to localstorage, memory
// storage for certain browsers in private mode
export class LocalStorageAlternative {
	private  structureLocalStorage = {};

	setItem(key: string, value: string): void {
		this.structureLocalStorage[key] = value;
	}

	getItem(key: string): string {
		if (typeof this.structureLocalStorage[key] !== 'undefined' ) {
			return this.structureLocalStorage[key];
		}
		return null;
	}

	removeItem(key: string): void {
		this.structureLocalStorage[key] = undefined;
	}
}

@Injectable()
export class StorageService {
	private storageEngine;

	constructor() {
		try {
			localStorage.setItem('storage_test', '');
			localStorage.removeItem('storage_test');
			this.storageEngine = localStorage;
		} catch (err) {
			this.storageEngine = new LocalStorageAlternative();
		}
	}

	setItem(key: string, value: string): void {
		this.storageEngine.setItem(key, value);
	}

	getItem(key: string): string {
		return this.storageEngine.getItem(key);
	}

	removeItem(key: string): void {
		this.storageEngine.removeItem(key);
	}

}

Don't use it if not supported and to check support just call this function

>sharing in Es6 full read and write localStorage Example with support check

const LOCAL_STORAGE_KEY = 'tds_app_localdata';

const isSupported = () => {
  try {
    localStorage.setItem('supported', '1');
    localStorage.removeItem('supported');
    return true;
  } catch (error) {
    return false;
  }
};


const writeToLocalStorage =
  components =>
    (isSupported ?
      localStorage.setItem(LOCAL_STORAGE_KEY, JSON.stringify(components))
      : components);

const isEmpty = component => (!component || Object.keys(component).length === 0);

const readFromLocalStorage =
  () => (isSupported ? JSON.parse(localStorage.getItem(LOCAL_STORAGE_KEY)) || {} : null);

> This will make sure your keys are set and retrieved properly on all browsers.

I have created a patch for the issue. Simply I am checking if the browser does support localStorage or sessionStorage or not. If not then the storage engine will be Cookie. But the negative side is Cookie have very tiny storage memory :(

function StorageEngine(engine) {
    this.engine = engine || 'localStorage';

    if(!this.checkStorageApi(this.engine)) {
        // Default engine would be alway cooke
        // Safari private browsing issue with localStorage / sessionStorage
        this.engine = 'cookie';
    }
}

StorageEngine.prototype.checkStorageApi = function(name) {
    if(!window[name]) return false;
    try {
        var tempKey = '__temp_'+Date.now();
        window[name].setItem(tempKey, 'hi')
        window[name].removeItem(tempKey);
        return true;
    } catch(e) {
        return false;
    }
}

StorageEngine.prototype.getItem = function(key) {
    if(['sessionStorage', 'localStorage'].includes(this.engine)) {
        return window[this.engine].getItem(key);
    } else if('cookie') {
        var name = key+"=";
        var allCookie = decodeURIComponent(document.cookie).split(';');
        var cval = [];
        for(var i=0; i < allCookie.length; i++) {
            if (allCookie[i].trim().indexOf(name) == 0) {
                cval = allCookie[i].trim().split("=");
            }   
        }
        return (cval.length > 0) ? cval[1] : null;
    }
    return null;
}

StorageEngine.prototype.setItem = function(key, val, exdays) {
    if(['sessionStorage', 'localStorage'].includes(this.engine)) {
        window[this.engine].setItem(key, val);
    } else if('cookie') {
        var d = new Date();
        var exdays = exdays || 1;
        d.setTime(d.getTime() + (exdays*24*36E5));
        var expires = "expires="+ d.toUTCString();
        document.cookie = key + "=" + val + ";" + expires + ";path=/";
    }
    return true;
}


// ------------------------
var StorageEngine = new StorageEngine(); // new StorageEngine('localStorage');
// If your current browser (IOS safary or any) does not support localStorage/sessionStorage, then the default engine will be "cookie"

StorageEngine.setItem('keyName', 'val')

var expireDay = 1; // for cookie only
StorageEngine.setItem('keyName', 'val', expireDay)
StorageEngine.getItem('keyName')

var mod = 'test';
      try {
        sessionStorage.setItem(mod, mod);
        sessionStorage.removeItem(mod);
        return true;
      } catch (e) {
        return false;
      }

The following script solved my problem:

// Fake localStorage implementation. 
// Mimics localStorage, including events. 
// It will work just like localStorage, except for the persistant storage part. 

var fakeLocalStorage = function() {
  var fakeLocalStorage = {};
  var storage; 
  
  // If Storage exists we modify it to write to our fakeLocalStorage object instead. 
  // If Storage does not exist we create an empty object. 
  if (window.Storage && window.localStorage) {
    storage = window.Storage.prototype; 
  } else {
    // We don't bother implementing a fake Storage object
    window.localStorage = {}; 
    storage = window.localStorage; 
  }
  
  // For older IE
  if (!window.location.origin) {
    window.location.origin = window.location.protocol + "//" + window.location.hostname + (window.location.port ? ':' + window.location.port: '');
  }

  var dispatchStorageEvent = function(key, newValue) {
    var oldValue = (key == null) ? null : storage.getItem(key); // `==` to match both null and undefined
    var url = location.href.substr(location.origin.length);
    var storageEvent = document.createEvent('StorageEvent'); // For IE, http://stackoverflow.com/a/25514935/1214183

    storageEvent.initStorageEvent('storage', false, false, key, oldValue, newValue, url, null);
    window.dispatchEvent(storageEvent);
  };

  storage.key = function(i) {
    var key = Object.keys(fakeLocalStorage)[i];
    return typeof key === 'string' ? key : null;
  };

  storage.getItem = function(key) {
    return typeof fakeLocalStorage[key] === 'string' ? fakeLocalStorage[key] : null;
  };

  storage.setItem = function(key, value) {
    dispatchStorageEvent(key, value);
    fakeLocalStorage[key] = String(value);
  };

  storage.removeItem = function(key) {
    dispatchStorageEvent(key, null);
    delete fakeLocalStorage[key];
  };

  storage.clear = function() {
    dispatchStorageEvent(null, null);
    fakeLocalStorage = {};
  };
};

// Example of how to use it
if (typeof window.localStorage === 'object') {
  // Safari will throw a fit if we try to use localStorage.setItem in private browsing mode. 
  try {
    localStorage.setItem('localStorageTest', 1);
    localStorage.removeItem('localStorageTest');
  } catch (e) {
    fakeLocalStorage();
  }
} else {
  // Use fake localStorage for any browser that does not support it.
  fakeLocalStorage();
}

It checks if localStorage exists and can be used and in the negative case, it creates a fake local storage and uses it instead of the original localStorage. Please let me know if you need further information.