XMLHttpRequestEventTarget: error event

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

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See full compatibility

Note: This feature is available in Web Workers, except for Service Workers.

The error event is fired when the request encountered an error.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

addEventListener("error", (event) => { })

onerror = (event) => { }

Event type

A ProgressEvent. Inherits from Event.

Examples

Usage with XMLHttpRequest

HTML

html

<div class="controls">
  <input
    class="xhr success"
    type="button"
    name="xhr"
    value="Click to start XHR (success)" />
  <input
    class="xhr error"
    type="button"
    name="xhr"
    value="Click to start XHR (error)" />
  <input
    class="xhr abort"
    type="button"
    name="xhr"
    value="Click to start XHR (abort)" />
</div>

<textarea readonly class="event-log"></textarea>

.event-log {
  width: 25rem;
  height: 4rem;
  border: 1px solid black;
  margin: 0.5rem;
  padding: 0.2rem;
}

input {
  width: 11rem;
  margin: 0.5rem;
}

JavaScript

const xhrButtonSuccess = document.querySelector(".xhr.success");
const xhrButtonError = document.querySelector(".xhr.error");
const xhrButtonAbort = document.querySelector(".xhr.abort");
const log = document.querySelector(".event-log");

function handleEvent(e) {
  log.textContent = `${log.textContent}${e.type}: ${e.loaded} bytes transferred\n`;
}

function addListeners(xhr) {
  xhr.addEventListener("loadstart", handleEvent);
  xhr.addEventListener("load", handleEvent);
  xhr.addEventListener("loadend", handleEvent);
  xhr.addEventListener("progress", handleEvent);
  xhr.addEventListener("error", handleEvent);
  xhr.addEventListener("abort", handleEvent);
}

function runXHR(url) {
  log.textContent = "";

  const xhr = new XMLHttpRequest();
  addListeners(xhr);
  xhr.open("GET", url);
  xhr.send();
  return xhr;
}

xhrButtonSuccess.addEventListener("click", () => {
  runXHR("example-image.jpg");
});

xhrButtonError.addEventListener("click", () => {
  runXHR("https://example.com/notfound.jpg");
});

xhrButtonAbort.addEventListener("click", () => {
  runXHR("example-image.jpg").abort();
});

Result

Usage with XMLHttpRequestUpload

You can use the error event to detect a problem with the upload. For a complete code example that uploads a file and displays a progress bar, see the main XMLHttpRequestUpload page.

// In case of an error we hide the progress bar
// Note that this event can be listened to on the xhr object too
function errorAction(event) {
  progressBar.classList.remove("visible");
  log.textContent = `Upload failed: ${event.type}`;
}
xhr.upload.addEventListener("error", errorAction);