Test IndexedDB's webkitIDBObjectStore.clear(). On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". webkitIndexedDB.open('objectstore-clear') db = event.target.result db.setVersion('new version') trans = event.target.result PASS trans !== null is true Deleted all object stores. store = db.createObjectStore('storeName', null) store.createIndex('indexName', '') PASS store.indexNames.contains('indexName') is true store.add('value', 'key') otherStore = db.createObjectStore('otherStoreName', null) otherStore.add('value', 'key') store.clear() PASS event.target.result is undefined. store.openCursor() PASS event.target.result is null index = store.index('indexName') index.openKeyCursor() openKeyCursorSuccess(): PASS event.target.result is null db.transaction({mode: webkitIDBTransaction.READ_WRITE}) otherStore = transaction.objectStore('otherStoreName') otherStore.get('key') PASS event.target.result is "value" PASS successfullyParsed is true TEST COMPLETE