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

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