The global indexedDB read-only property provides a mechanism for applications to asynchronously access the capabilities of indexed databases.

An IDBFactory object.

The following code creates a request for a database to be opened asynchronously, after which the database is opened when the request's onsuccess handler is fired:

let db;
function openDB() {
  const DBOpenRequest = window.indexedDB.open("toDoList");
  DBOpenRequest.onsuccess = (e) => {
    db = DBOpenRequest.result;
  };
}

• Using IndexedDB
• Starting transactions: IDBDatabase
• Using transactions: IDBTransaction
• Setting a range of keys: IDBKeyRange
• Retrieving and making changes to your data: IDBObjectStore
• Using cursors: IDBCursor
• Reference example: To-do Notifications (View the example live).