The bound() method of the IDBKeyRange interface creates a new key range with upper and lower bounds.

The bounds can be open (that is, the bounds exclude the endpoint values) or closed (that is, the bounds include the endpoint values). By default, the bounds are closed.

Note: This feature is available in Web Workers.


myKeyRange = IDBKeyRange.bound("A", "Z", true, true);


IDBKeyRange: The newly created key range.


This method may raise a DOMException of the following type:

Exception Description

The following conditions raise an exception:

  • The lower or upper parameters were not passed a valid key.
  • The lower key is greater than the upper key.
  • The lower key and upper key match and either of the bounds are open.


The following example illustrates how you'd use a bound key range. Here we declare a keyRangeValue = IDBKeyRange.bound("A", "F"); — a range between values of "A" and "F". 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 records with keys inside that range. This range includes the values "A" and "F", as we haven't declared that they should be open  bounds. If we used IDBKeyRange.bound("A", "F", true, true);, then the range would not include "A" and "F", only the values between them.

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.bound("A", "F");

  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 lower bound of the key range.
The upper bound of the key range.
Optional. If false (default value), the range includes the lower bound value of the key range.
Optional. If false (default value), the range includes the upper bound value of the key range.


Specification Status Comment
Indexed Database API
The definition of 'bound()' in that specification.
Editor's Draft  

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
Available in workers (Yes) 37.0 (37.0) ? (Yes) ?
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 8
Available in workers (Yes) 37.0 (37.0) (Yes) ? (Yes) ?

See also

Document Tags and Contributors

 Contributors to this page: jpmedley, inexorabletash, chrisdavidmills, fscholz, trevorh
 Last updated by: jpmedley,