asp.net mvc dynamic form builder

For ASP.NET MVC specifically, this splits into a few genuinely different approaches — client-side JSON-schema libraries, server-side C# form-generation packages, and UI-kit-provided dynamic form tooling. Here's the landscape:

SurveyJS — the most complete, actively maintained option

• An open-source form builder component that simplifies the creation of dynamic and responsive JSON-driven forms on the client side and easily integrates with an ASP.NET Core backend. It's a client-side JavaScript library that seamlessly integrates into your frontend application and communicates with an ASP.NET Core backend via HTTP requests and responses, with a drag-and-drop form builder providing a rich collection of accessible form components plus API examples for managing client-server interactions.
• You can easily create dynamic forms of any complexity using the drag-and-drop interface, define validation rules, add conditional logic, and customize the form layout — once your form is ready, automatically save its output (a JSON form schema) in a database.
• Comes with a working starter you can run directly: git clone https://github.com/surveyjs/surveyjs-aspnet-mvc.git → dotnet build → dotnet run. This is the most actively documented and maintained option of the group — the others below are largely older, community-maintained side projects.

MvcDynamicForms / MvcDynamicFormsNetCore — lightweight, server-side C# option

• A fork of ronnieoverby's original ASP.NET MVC Dynamic Forms project, updated for MVC5 since the original (written for MVC2 and below) is no longer maintained. A further fork brings it to .NET 7 specifically, still under active development, open source and accepting contributions. The core model: you construct Form and Field objects in C#, and the library renders the HTML (Model.RenderHtml()) — the Form object graph can be persisted across requests via serialization to a hidden field, TempData, or your own storage. A genuinely lightweight, no-JS-framework-dependency approach if you want dynamic forms defined and rendered entirely in C# rather than via a client-side JSON schema.

FormFactory — reflection-based, auto-generates forms from your object model

• Renders complex object forms automatically by reflecting over an object model or method signature, building an intermediate model representing the form and properties, then rendering via customizable templates. Can build complex nested forms with rich content pickers, and by following a few code conventions, properties with multiple choices and suggested values can be written in a few lines of code. FormFactory.Standalone can also be used in non-ASP projects (console apps, services, WebAPI). Best if your forms map directly to existing C# model classes and you want the form generated automatically from that shape, rather than authored as a separate schema.

Telerik UI for ASP.NET MVC — commercial UI-kit approach

• Telerik's ASP.NET MVC Forms component supports creating dynamic forms populated through a JSON file — a reasonable option if you're already licensing Telerik's broader component suite and want dynamic form generation integrated with the rest of that UI kit rather than adopting a separate library.

How to choose

• Want the most feature-complete, actively maintained, JSON-schema-driven builder with a visual authoring UI → SurveyJS.
• Want a lightweight, purely server-side C# solution with no client-side JS framework dependency → MvcDynamicForms (or the .NET 7 fork, MvcDynamicFormsNetCore).
• Want forms auto-generated by reflecting over your existing C# model classes → FormFactory.
• Already using Telerik's commercial component suite → Telerik UI for ASP.NET MVC's JSON-driven Forms.

Bottom line: for a genuinely dynamic, well-documented, and actively maintained ASP.NET MVC/Core form builder, SurveyJS is the clearest choice — it's the only option here with a real visual builder, ongoing maintenance, and dedicated ASP.NET Core integration examples. If you specifically want to avoid any client-side JSON-schema library and keep everything in C#, MvcDynamicForms (or its .NET 7 fork) and FormFactory are the lighter-weight, code-first alternatives worth evaluating.