Oakley
FastField offers Free Trial, but Gravity Forms does not.
FastField is designed for Individuals, Medium Business and Small Business.
Gravity Forms is designed for Large Enterprises, Medium Business and Small Business.
Pricing for FastField Starts at $23/user/month when yearly whereas for Gravity Forms Starts at $59/Year.
Some top alternatives to FastField includes Cognito Forms, Formsite, Typeform, MightyForms, 123FormBuilder, stepFORM, Microsoft Forms, GoCanvas, Jotform Mobile Forms, Forms.io by 500apps, FormLink and Formee.
Some top alternatives to Gravity Forms includes Formidable Forms, Cognito Forms, Formsite, Formstack, Paperform, Typeform, Jotform, MightyForms, weForms, Ninja Forms, WPForms and FormLink.