Zoom

As a mature conference call service, Zoom provides users a secure experience while joining the meeting. You are able to use it anywhere on any devices. And users can not only bring HD video and audio to their meetings, but also share their screens simultaneously for a more interactive meeting.

With Zoom, you can host up to 100 participants. And the time limit of the call is 40 minutes, unless you are from K-12 Schools. Because it temporarily lifts the 40-minute time limit on free Basic accounts for schools affected by the coronavirus.

2021 Top 9 Free Conference Call Services： https://www.vidmore.com/record-video/best-free-conference-call-service/