Zendesk Support offers Free Trial, but Redpen does not.
Zendesk Support is designed for Large Enterprises, Medium Business and Small Business.
Redpen is designed for Large Enterprises, Small Business and Medium Business.
Pricing for Zendesk Support Starts at $19/user/month when yearly whereas for Redpen Starts at $7.95per month when Billed Yearly.
Some top alternatives to Zendesk Support includes Zoho Desk, Tidio Helpdesk, Deskero, Support Hub, HelpDesk, Desky, Help Scout, Salesforce Service Cloud, ReadyDesk, Sitehelpdesk, HESK and BoldDesk.
Some top alternatives to Redpen includes and undefined.