When comparing these two products, the main differences that stand out are plan limits and included features. The cost of Submit JSON and FormBackend is similar.
FormBackend's monthly plans start at $5/month with a submission limit of 1,000. Compare that to Submit JSON's $5/month plan with 2500 submissions. That 2.5x ratio stays true comparing all of the pricing plans.
Hate to say it, but FormBackend simply copied Formspree, right down to the logo. They fall short where Formspree falls short. You should check out how Submit JSON stacks up aginst Formspree, as we have very different design philosphies.
Which is the best form backend for you? We think the answer is obvious, but we'll let you decide.