FormForge

About FormForge

FormForge is an API that converts a JSON form definition into a fully styled, self-contained HTML form, returned as an HTML string via a single POST request. The generated output includes embedded CSS and vanilla JavaScript with no external dependencies, and is meant to be embedded directly into a page, injected via innerHTML, or placed in an iframe. Requests are made to /api/json-to-form or /api/json-to-embed with an API key, specifying a title, theme, submit URL, and a list of fields with name, type, label, and validation rules.

The API supports ten field types (text, email, number, textarea, select, checkbox, radio, date, tel, url) and four visual themes (modern, corporate, playful, minimal), with CSS variables available for further customization. Generated forms include client-side validation for required fields, email/URL/phone format, and number ranges, along with ARIA attributes and error regions for accessibility. When a submitUrl is provided, the form also handles the fetch submission along with loading, success, and error states.

FormForge is aimed at developers who need to generate forms programmatically without building form UI and validation logic by hand, and is usable from any language or framework via plain REST calls (no SDK required). Pricing is tiered by daily form-generation volume and input size limit: a free plan (20 forms/day, 50 KB input limit), a Builder plan at $14/month (300 forms/day, 512 KB input limit, rate-limit headers, email support), and an Enterprise plan at $39/month (unlimited forms, 5 MB input limit, priority support, SLA).

Key features

• Converts JSON form schemas into styled, accessible HTML via a single API call
• Supports 10 field types: text, email, number, textarea, select, checkbox, radio, date, tel, url
• Ships with 4 built-in themes (modern, corporate, playful, minimal) with overridable CSS
• Built-in client-side validation for required fields, email/URL/phone format, and number ranges
• Generates self-contained HTML with zero dependencies, embeddable via iframe or innerHTML
• Optional async submit handling: pass a submitUrl and the form manages fetch, loading, and error states

Frequently asked questions