Neither Lightkey nor ProWritingAid offers a free trial.
Lightkey is designed for Individuals, Large Enterprises, Medium Business and Small Business.
ProWritingAid is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Lightkey Starts at $39.95/User/Month whereas for ProWritingAid Starts at $20/Month.
Some top alternatives to Lightkey includes ProWritingAid, Linguix, Grammarly Business, WritingAssistant, Writer, TextWizard, Ginger and Copylime.
Some top alternatives to ProWritingAid includes Gramara, WritingAssistant, Writer, Essaybot, QuillBot, Ginger and PaperRater.