This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The clearHalt() method of the USBDevice interface returns a promise that resolves when a halt condition is cleared. A halt condition is when a data tranfer to or from the device has a status of 'stall', which requires the web page (the host system, in USB terminology) to clear that condition. See the for details.


var promise = USBDevice.clearHalt(direction, endpointNumber)


Indicates whether the devices input or output should be cleared. Valid values are 'in' or 'out'.
Indicates the number of the endpoint to clear. The promise will reject if an invalid endpoint is supplied.

Return value

A promise.


The following example shows how to test for and clear a 'stall' condition in the result of a data transfer.

What data can be passed to a USB device and how it is passed is particular and unique to each device.

while (true) {
  let result = await data.transferIn(1, 6);

  if ( && === 6) {
    console.log('Channel 1: ' +;
    console.log('Channel 2: ' +;
    console.log('Channel 5: ' +;

  if (result.status === 'stall') {
    console.warn('Endpoint stalled. Clearing.');
    await device.clearHalt('in', 1);


Specification Status Comment
The definition of 'clearHalt()' in that specification.
Draft Initial definition.

Browser compatibility

ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Chrome Full support 61Edge Full support 79Firefox No support NoIE No support NoOpera Full support 48Safari No support NoWebView Android No support NoChrome Android Full support 61Firefox Android No support NoOpera Android Full support 45Safari iOS No support NoSamsung Internet Android Full support 8.0


Full support
Full support
No support
No support
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.