PingStack offers Free Trial, but UpTime.onl does not.
PingStack is designed for Medium Business and Small Business.
UpTime.onl is designed for Individuals, Medium Business and Small Business.
Pricing for PingStack Starts at $9/Month whereas for UpTime.onl Starts at $10/Month.
Some top alternatives to PingStack includes Uptime, Uptime Robot, Hyperping, DevMonitor.io, UpTime.onl, CallView 360, SiteUptime, pingnow.io, WatchSumo and Loadping.
Some top alternatives to UpTime.onl includes Uptime, CHEQ.ONLINE, Uptime Robot, Super Monitoring, DevMonitor.io, Odown, Uptrends, Domain Monitor, 66uptime and Pingt.io.