When comparing Submit JSON and FormKeep, the biggest differences are pricing model, submission limits, and overall product focus.
FormKeep's paid plans start at $4.99/month for 1,000 submissions (with form-count limits by tier). Submit JSON's closest paid tier starts at $15/month with 10,000 submissions, and scales to 50,000 submissions at $49/month.
FormKeep can be a fit if you need its hosted builder workflows and are comfortable with per-form pricing on paid tiers.
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