Zendesk is the more common of the two in our index: it runs on 8,725 websites against 19 for Provide Support. Counts come from real scans of each site's home page, not vendor claims, and cover the sites in TechLookup's index rather than the whole web.
Provide Support is a SaaS for customer service that includes live chat, real-time website monitoring, chat statistics.
Zendesk is a cloud-based help desk management solution offering customizable tools to build customer service portal, knowledge base and online communities.
Within the live chat sites we have indexed, Provide Support holds 0.1% and Zendesk 43%.
Want to know which one a particular site uses? Look it up and see its whole stack, or compare two sites side by side.