What is the best free 360 feedback software?

Two tools publish a genuinely usable free tier rather than a trial. Effy AI is free for up to 5 users with full 360 review access and no credit card. Teamflect is free for up to 10 users with full functionality, which makes it the more generous of the two, though it only makes sense if your company runs on Microsoft Teams. Beyond those, what is marketed as free is usually a time-limited trial: Teamflect offers 30 days on paid plans, 15Five 14 days, Pointerpro 14 days, and Spidergap and CustomInsight each let you run one assessment or one participant at no cost. Survey builders can technically run a 360 free of charge, but none of them handle rater nomination, anonymity thresholds or per-competency reporting, so you pay in admin time instead.