Yes, both StructHub and ProProfs Knowledge Base offer a Free Trial.
StructHub is designed for Large Enterprises, Medium Business and Small Business.
ProProfs Knowledge Base is designed for Large Enterprises, Medium Business and Small Business.
Pricing for StructHub Starts at $129/Month when Billed Yearly whereas for ProProfs Knowledge Base Starts at $0.30/Month when Billed Yearly.
Some top alternatives to StructHub includes KBPublisher, SmartSupport, Talisma KnowledgeBase, HelpHub, KnowledgeOwl, Qualified, Workvivo, PaceKB, KnowledgeBase, Whatis, ProProfs Knowledge Base and IFTTT.
Some top alternatives to ProProfs Knowledge Base includes KBPublisher, SmartSupport, Talisma KnowledgeBase, HelpHub, KnowledgeOwl, Qualified, Workvivo, PaceKB, KnowledgeBase, Whatis, IFTTT and StructHub.