A computer-implemented method for performing voice actions on computing devices, comprising: monitoring, at a computing device, a voice input of a computing device for a spoken prefix that occurs in the voice input, wherein the computing device is configured to perform a particular action in response to detecting the spoken prefix; transmitting, from the computing device, audio data for some or all of the voice input to a server system that is remote from the computing device; identifying, at the server system and by performing speech-to-text conversion on the audio data, one or more terms that follow the spoken prefix in the voice input; determining, at the server system, an argument to the action that the computing device is configured to perform responsive to detection of the spoken prefix, wherein the server system determines the argument based on a result of a search performed by a search engine of the server system on the identified one or more terms that follow the spoken prefix in the voice input; transmitting the argument from the server system to the computing device; and performing, at the computing device in response to detecting the spoken prefix that occurs in the voice input, the action according to the argument determined at the server system, characterised in that the prefix comprises an instruction to execute a navigation application, and the one or more terms describe a geographical landmark, and wherein determining the argument comprises parsing a landing page corresponding to a search result for a designated type of information, the designated type of information comprising a location for the search result. monitoring, at a computing device, a voice input of a computing device for a spoken prefix that occurs in the voice input, wherein the computing device is configured to perform a particular action in response to detecting the spoken prefix; transmitting, from the computing device, audio data for some or all of the voice input to a server system that is remote from the computing device; identifying, at the server system and by performing speech-to-text conversion on the audio data, one or more terms that follow the spoken prefix in the voice input; determining, at the server system, an argument to the action that the computing device is configured to perform responsive to detection of the spoken prefix, wherein the server system determines the argument based on a result of a search performed by a search engine of the server system on the identified one or more terms that follow the spoken prefix in the voice input; transmitting the argument from the server system to the computing device; and performing, at the computing device in response to detecting the spoken prefix that occurs in the voice input, the action according to the argument determined at the server system, characterised in that the prefix comprises an instruction to execute a navigation application, and the one or more terms describe a geographical landmark, and wherein determining the argument comprises parsing a landing page corresponding to a search result for a designated type of information, the designated type of information comprising a location for the search result.