Yes, both Kustomer and Zendesk Support offer a Free Trial.
Kustomer is designed for Large Enterprises, Medium Business and Small Business.
Zendesk Support is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Kustomer Starts at $29/User/Month whereas for Zendesk Support Starts at $19/user/month when yearly.
Some top alternatives to Kustomer includes Zoho Desk, Zendesk Support, ManageEngine ServiceDesk Plus, Zendesk Sell, Freshservice, Freshdesk, HelpDesk, SysAid, Jitbit Helpdesk, Desky, Salesforce Service Cloud, CRMdesk, Gorgias, Trakdesk, AzureDesk and BoldDesk.
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.