/Web APIs

IDBKeyRange: bound() static method

The bound() method of the IDBKeyRange interface creates a new key range with the specified 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


IDBKeyRange.bound(lower, upper)
IDBKeyRange.bound(lower, upper, lowerOpen)
IDBKeyRange.bound(lower, upper, lowerOpen, upperOpen)



specifies the lower bound of the new key range.


specifies the upper bound of the new key range.

lowerOpen Optional

indicates whether the lower bound excludes the endpoint value. The default is false.

upperOpen Optional

Indicates whether the upper bound excludes the endpoint value. The default is false.

Return value

IDBKeyRange: The newly created key range.


DataError DOMException

Thrown when one of the following conditions is met:

  • 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 the idbkeyrange directory in the indexeddb-examples repo. (View the example live too.

function displayData() {
  const keyRangeValue = IDBKeyRange.bound("A", "F");

  const transaction = db.transaction(["fThings"], "readonly");
  const objectStore = transaction.objectStore("fThings");

  objectStore.openCursor(keyRangeValue).onsuccess = (event) => {
    const cursor = event.target.result;
    if (cursor) {
      const listItem = document.createElement("li");
      listItem.textContent = `${cursor.value.fThing}, ${cursor.value.fRating}`;

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


Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
bound 23 12 10 10 15 8 4.4 25 22 14 8 1.5

See also

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