saveButton.addEventListener('click', function () {
  window.localStorage.setItem('value', textarea.value);
}, false);
textarea.value = window.localStorage.getItem('value');
window.localStorage.clear();

Save text value on the client side (crash-safe)

	var el = document.querySelector('#myID');
	// place content from local storage on load if there is one
	el.innerHTML = window.localStorage.getItem('value');

var items = window.localStorage.length;
var lastItem = window.localStorage.key(items-1);
localStorage.removeItem('timestamp');

var db = window.openDatabase("DBName", "1.0", "description", 5*1024*1024); 
  db.transaction(function(tx) {
  tx.executeSql("SELECT * FROM test", [ ], successCallback, errorCallback);
});

• Chrome
• Safari
• Firefox
• Opera
• IE 8
• Well Supported but deprecated November 18, 2010

Object Store ≠ Relational Database

Storage of structured data

Asynchronous API → doesn't block thread

IDBRequestObject = window.IndexedDB.open('dbName');

IDBCursor

iterates over object stores and indexes.

IDBDatabase

connection to a database. It's the only way to get a transaction on the database.

IDBFactory

provides access to a database.

IDBEnvironment

provides access to a client-side database. It is implemented by window objects.

IDBIndex

provides access to the metadata of an index.

IDBObjectStore

an object store.

IDBOpenDBRequest

a request to open a database.

IDBRequest

provides access to results of asynchronous requests to databases and database objects. It is what you get when you call an asynchronous method.

IDBTransaction

a transaction. You create a transaction on a database, specify the scope (such as which object stores you want to access), and determine the kind of access (read only or write) you want.

IDBVersionChangeEvent

indicates that the version of the database has changed.

IDBDatabaseException

exception conditions that can be encountered while performing database operations.

IDBKeyRange

defines a range of keys.