Free tier

A free plan, on-demand trial credits, or free evaluation tier without a paid seat.

2 of 4 tools marked Yes.

Tool	Status	Notes	Source
Inworld	Yes	On-Demand $0 pay-as-you-go; up to ~70 min TTS included	Source
Convai	Yes	Free: 100 interactions/mo, 60 mins cloud studio, 1 concurrency	Source
Charisma	Partial	Docs describe a one-month free trial with 50,000 credits	Source
NVIDIA ACE	Partial	Developer prototyping commonly free; production via NVIDIA AI Enterprise (page fetch timed out — confirm on NVIDIA site)	Source