IDBRequest: error property

Note: This feature is available in Web Workers.

The error read-only property of the IDBRequest interface returns the error in the event of an unsuccessful request.


A DOMException or null if there is no error. The following error names are returned in the exception object:


If you abort the transaction, then all requests still in progress receive this error.


If you insert data that doesn't conform to a constraint. It's an exception type for creating stores and indexes. You get this error, for example, if you try to add a new key that already exists in the record.


If you run out of disk quota and the user declined to grant you more space.


If the operation failed for reasons unrelated to the database itself. A failure due to disk IO errors is such an example.


If you try to open a database with a version lower than the one it already has.

In addition to the error codes sent to the IDBRequest object, asynchronous operations can also raise exceptions. The list describes problems that could occur when the request is being executed, but you might also encounter other problems when the request is being made. For example, if the result is accessed while the request is not completed, the InvalidStateError exception is thrown.


The following example requests a given record title, onsuccess gets the associated record from the IDBObjectStore (made available as objectStoreTitleRequest.result), updates one property of the record, and then puts the updated record back into the object store. Also included at the bottom is an onerror function that reports what the error was if the request fails. For a full working example, see our To-do Notifications app (View the example live).

const title = "Walk dog";

// Open up a transaction as usual
const objectStore = db
  .transaction(["toDoList"], "readwrite")

// Get the to-do list with the specified title
const objectStoreTitleRequest = objectStore.get(title);

objectStoreTitleRequest.onsuccess = () => {
  // Grab the data object returned as the result
  const data = objectStoreTitleRequest.result;

  // Update the notified value in the object to "yes"
  data.notified = "yes";

  // Create another request that inserts the item
  // back into the database
  const updateTitleRequest = objectStore.put(data);

  // When this new request succeeds, run the displayData()
  // function again to update the display
  updateTitleRequest.onsuccess = () => {

objectStoreTitleRequest.onerror = () => {
  // If an error occurs with the request, log what it is
    `There has been an error with retrieving your data: ${objectStoreTitleRequest.error}`,


Indexed Database API 3.0
# ref-for-dom-idbrequest-error①

Browser compatibility

BCD tables only load in the browser

See also