When comparing Submit JSON and Formspark, the biggest differences are pricing model, submission limits, and overall product focus.
Formspark uses a one-time credit model: 250 free submissions, then a $50 bundle for 50,000 submissions. Submit JSON's closest paid tier starts at $15/month with 10,000 submissions, and scales to 50,000 submissions at $49/month.
Formspark can be a fit if you prefer one-time purchases over recurring subscriptions.
If you want an API-first backend that gives you full control over UX and works cleanly with modern JavaScript stacks, Submit JSON is usually the stronger fit.
Pricing and limits verified from public pricing/docs pages in April 2026; competitor plans may change over time.
Google Sheets integration