Conform is a React form validation library that progressively enhances native HTML forms: it validates FormData against a Zod, Valibot or Yup schema on the server and, optionally, on the client, so a form works before JavaScript loads. Use when a user asks to build a form with Conform, validate a Next.js Server Action or a React Router / Remix action, share one schema between client and server, add or remove rows in a field list, or move to Conform's future API.