Slack offers Free Trial, but InstaSafe ZTAA does not.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
InstaSafe ZTAA is designed for Large Enterprises and Medium Business.
Pricing for Slack Starts at $2.67/Month whereas for InstaSafe ZTAA Starts at $8/User/Month.
Some top alternatives to Slack includes Microsoft Teams, Glip, Google Chat, ChatWork, Dialog, Office Chat, imBee, Takle, SPACE Channel and Teamwork Chat.
Some top alternatives to InstaSafe ZTAA includes AppOmni, Instasafe Secure Access, SafeNet Trusted Access, DoControl, Qualified, Workvivo, AppSec360, Adaptive Shield, SafeBase, BetterCloud, IFTTT and SaaSTrax.