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This article is in need of a technical review.

The only() method of the IDBKeyRange interface creates a new key range containing a single value.


myKeyRange = IDBKeyRange.only("A");


IDBKeyRange: The newly created key range.


This method may raise a DOMException with a DOMError of the following types:

Exception Description

The value parameter passed was not a valid key.



The following example illustrates how you'd use an only key range. Here we declare a keyRangeValue = IDBKeyRange.only("A"); — a range that only includes the value "A". We open a transaction (using IDBTransaction) and an object store, and open a Cursor with IDBObjectStore.openCursor, declaring keyRangeValue as its optional key range value. This means that the cursor will only retrieve the record with the key value "A".

Note: For a more complete example allowing you to experiment with key range, have a look at our IDBKeyRange-example repo (view the example live too.)

function displayData() {
  var keyRangeValue = IDBKeyRange.only("A");

  var transaction = db.transaction(['fThings'], 'readonly');
  var objectStore = transaction.objectStore('fThings');

  objectStore.openCursor(keyRangeValue).onsuccess = function(event) {
    var cursor =;
      if(cursor) {
        var listItem = document.createElement('li');
        listItem.innerHTML = '<strong>' + cursor.value.fThing + '</strong>, ' + cursor.value.fRating;
      } else {
        console.log('Entries all displayed.');


The single value in the key range.


Specification Status Comment
Indexed Database API
The definition of 'only' in that specification.
Candidate Recommendation  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 23webkit
10 moz
16.0 (16.0)
10, partial 15 7.1
Feature Android Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support 4.4 22.0 (22.0) 1.0.1 10 22 Not supported

See also

Document Tags and Contributors

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