index.md

---

title: AbortController.signal
slug: Web/API/AbortController/signal
page-type: web-api-instance-property
browser-compat: api.AbortController.signal

---

{{APIRef("DOM")}}

The signal read-only property of the {{domxref("AbortController")}} interface returns an {{domxref("AbortSignal")}} object instance, which can be used to communicate with/abort a DOM request as desired.

Value

An {{domxref("AbortSignal")}} object instance.

Examples

In the following snippet, we aim to download a video using the Fetch API.

We first create a controller using the {{domxref("AbortController.AbortController","AbortController()")}} constructor, then grab a reference to its associated {{domxref("AbortSignal")}} object using the {{domxref("AbortController.signal")}} property.

When the fetch request is initiated, we pass in the AbortSignal as an option inside the request's options object (the {signal} below). This associates the signal and controller with the fetch request and allows us to abort it by calling {{domxref("AbortController.abort()")}}, as seen below in the second event listener.

const controller = new AbortController();
const signal = controller.signal;

const url = "video.mp4";
const downloadBtn = document.querySelector(".download");
const abortBtn = document.querySelector(".abort");

downloadBtn.addEventListener("click", fetchVideo);

abortBtn.addEventListener("click", () => {
  controller.abort();
  console.log("Download aborted");
});

function fetchVideo() {
  fetch(url, { signal })
    .then((response) => {
      console.log("Download complete", response);
    })
    .catch((err) => {
      console.error(`Download error: ${err.message}`);
    });
}

Note: When abort() is called, the fetch() promise rejects with an AbortError.

You can find a full working example on GitHub; you can also see it running live.

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• Fetch API