Yes, both Zendesk Support and Aircall offer a Free Trial.
Zendesk Support is designed for Large Enterprises, Medium Business and Small Business.
Aircall is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Pricing for Zendesk Support Starts at $19/user/month when yearly whereas for Aircall Starts at $30/User/Month.
Some top alternatives to Zendesk Support includes Zoho Desk, ManageEngine ServiceDesk Plus, Deskero, Support Hub, HelpDesk, Desky, Help Scout, Salesforce Service Cloud, ReadyDesk, Sitehelpdesk, HESK and BoldDesk.
Some top alternatives to Aircall includes Novanet Cloud Contact Center, CloudTalk, HoduCC, Call Center Studio, Dialpad Contact Center, 3CX, Vonage Contact Center and RingCentral Contact Center.