Is the free and basic plan GDPR compliant or just the more expensive packages?

All our plans are GDPR compliant. What's important to do from your end is ensure that you're using our EU based datacenter.

If you haven't done that yet, I recommend you move your data to our EU servers. You can do that on your Account's Data page. To learn more about GDPR compliance, I recommend you review the contents of this page:

https://www.jotform.com/gdpr-compliance/