This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for the proper prefixes to use in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the spec changes.

The isAutoLocale read-only property of the IDBIndex interface returns a Boolean indicating whether the index had a locale value of auto specified upon its creation (see createIndex()'s optionalParameters.)


var myIndex = objectStore.index('index');


A Boolean.


In the following example we open a transaction and an object store, then get the index lName from a simple contacts database. We then open a basic cursor on the index using IDBIndex.openCursor — this works the same as opening a cursor directly on an ObjectStore using IDBObjectStore.openCursor except that the returned records are sorted based on the index, not the primary key.

The isAutoLocale value is logged to the console.

function displayDataByIndex() {
  tableEntry.innerHTML = '';
  var transaction = db.transaction(['contactsList'], 'readonly');
  var objectStore = transaction.objectStore('contactsList');

  var myIndex = objectStore.index('lName'); 

  myIndex.openCursor().onsuccess = function(event) {
    var cursor =;
    if(cursor) {
      var tableRow = document.createElement('tr');
      tableRow.innerHTML =   '<td>' + + '</td>'
                           + '<td>' + cursor.value.lName + '</td>'
                           + '<td>' + cursor.value.fName + '</td>'
                           + '<td>' + cursor.value.jTitle + '</td>'
                           + '<td>' + + '</td>'
                           + '<td>' + cursor.value.eMail + '</td>'
                           + '<td>' + + '</td>'
                           + '<td>' + cursor.value.age + '</td>';

    } else {
      console.log('Entries all displayed.');    


Not currently part of any specification.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support Not supported 43.0 (43.0)[1] Not supported Not supported Not supported
Feature Android Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support Not supported 43.0 (43.0)[1] 2.5[1] Not supported Not supported Not supported

[1] This feature is currently hidden behind a flag — to enable it and experiment, go to about:config and enable dom.indexedDB.experimental.

See also

Document Tags and Contributors

 Contributors to this page: Sebastianz, chrisdavidmills
 Last updated by: Sebastianz,