Yes, both CloudTalk and Zendesk Talk offer a Free Trial.
CloudTalk is designed for Large Enterprises, Medium Business and Small Business.
Zendesk Talk is designed for Individuals, Large Enterprises, Medium Business and Small Business.
Pricing for CloudTalk Starts at $25/User/Month when Billed Yearly whereas for Zendesk Talk Starts at $9/User/Month.
Some top alternatives to CloudTalk includes Nextiva, CallTools, HoduCC, Call Center Studio, Truly, Aircall, JustCall, Dialpad Contact Center, RingCentral Contact Center, VoxDesk and Squaretalk.
Some top alternatives to Zendesk Talk includes Nextiva, TalkDesk, uContact, HoduCC, Call Center Studio, TelebuHub, Zendesk Support, VoxDesk, Zendesk Chat and Freshdesk Contact Center (Formerly Freshcaller).