MDN рекомендует такую функцию:
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);
}
}
Применение:
if (storageAvailable('localStorage')) {
// Yippee! We can use localStorage awesomeness
}
else {
// Too bad, no localStorage for us
}