Some natural language command processing systems may handle some commands on a user device rather than sending input to another system for processing. Such a system may include an arbitration component for arbitrating between device and/or system processing. The arbitration component may execute in the system and render a device-specific decision as to whether the device will be able to process the input and/or execute the command, based on information known to the system about the device's capabilities. If the arbitration component predicts that the device will not be able to execute the command, the system may execute the command without waiting for a signal from the device. If the arbitration component predicts that the device will be able to execute the command, the system may halt processing to prevent duplicate execution.