Every conference call service provider has unique rules regarding the number of participants that you can host in a conference call. Some platforms cap you at ten participants, while others allow you to host up to 1,000 users.  Therefore, the call duration and the number of users for your conferences depend on the service provider you select. Some platforms limit your options to free plans but offer extra features at additional charges. For example, FreeConferenceCall allows you to host free audio and video conferencing for up to 1,000 users.