A speech interface device is configured to switch between languages, at the request of a user, in order to locally process utterances spoken in different languages, even in instances when a remote system is unavailable to, slower than, or otherwise less preferred than the speech interface device. For example, a user can request to set the language setting of the speech interface device to a second language, different from a first language to which the language setting of the device is currently set. Based on this user request, a local speech processing component of the device may load a language model(s) associated with the second language. The speech interface can also output voice prompts in the second language to manage the user's experience while a language update is in progress on the speech interface device.