Offline Add, Edit, Delete Data in HTML5 IndexedDB

You can use HTML5 web storage, IndexedDB or File access API in your app to provide offline support. It allows user to work offline when the network isn’t available. An IndexedDB is a persistent data store in the browser means a database on the client side. It allows you to create app with rich query abilities in both offline and online mode. If you are beginner with IndexedDB, you should first read Using IndexedDB.