How to monitor the efficiency of freelancers?

What service is the best way to monitor the efficiency of freelancers' work? I have several remote specialists working in my team, and sometimes I notice that deadlines are missed and tasks take longer than expected. Of course, I realize that freelancers are not office employees, but I still want to somehow monitor their productivity without turning into a dictator. Ideally, I would like to find a tool that will help me see how much time is spent on tasks, but at the same time will not create tension in communication. Maybe someone has already tried something like this?