Neither NLP-API nor Agent4 offers a free trial.
NLP-API is designed for Large Enterprises, Medium Business and Small Business.
Agent4 is designed for Large Enterprises, Small Business and Medium Business.
Pricing for NLP-API Starts at $16/Month when Billed Yearly whereas for Agent4 Starts at $10.00per month when Billed Yearly.
Some top alternatives to NLP-API includes Rakebots, Amazon Comprehend, XEditPro, IBM Watson Assistant, JAICP, yellow.ai, Deepset, Spark NLP, Forefront and SyTrue.
Some top alternatives to Agent4 includes and undefined.