Visual Form Builders for Web Agencies (Open Source Guide)

For modern web agencies and developers, time is money. Whether you're launching a marketing site, onboarding users, or collecting customer feedback, forms are everywhere. And yet, they remain one of the most repetitive parts of front-end development.

Enter the visual form builder.

Instead of hand-coding every input and validation rule, visual form builders let you drag and drop your way to working forms — reducing dev time, empowering non-technical collaborators, and delivering better UX to your clients.

And when these tools are open source, self-hostable, and developer-friendly? You get speed, flexibility, and control.

In this post, we’ll explore:

• Why visual form builders make business sense for agencies
• The top open-source form builder options today
• And why Better Stack’s Form Builder plugin is a top contender for teams building with modern full stack frameworks

Why Use a Visual Form Builder?#

1. Build Faster, Bill Smarter#

Time spent wiring up inputs, validations, and layouts is time you’re not spending on custom features or shipping projects. Visual builders streamline the routine — allowing your team to move faster and deliver on tighter deadlines.

2. Empower Non-Tech Contributors#

Marketers, content editors, and project managers shouldn’t have to open VS Code to update a form. Visual builders let them build and tweak forms directly, reducing dev bottlenecks.

3. Improve UX and Conversion#

Forms that are interactive, styled well, and broken into logical steps perform better. Builders that support conditional logic, multi-step layouts, and validation out-of-the-box make it easy to launch high-converting forms.

4. Own Your Data and UX#

Open-source builders let you self-host and keep control of your data — ideal for privacy-focused clients or compliance-heavy industries. You’re not locked into a SaaS product or design system.

Top Open Source Form Builders for Developers and Agencies#

Here’s a breakdown of standout form builders (with a spotlight on Better Stack’s new Form Builder plugin):

🧰 Budibase#

A low-code platform that includes a visual form builder, built-in database, and automation. Great for internal tools and dashboards.

• Drag-and-drop UI with theming
• Works with external databases
• Plugin system for customization

Best for: internal apps, CRUD tools, business platforms

🏢 Form.io#

Enterprise-level form builder with REST API generation and complex validation. Ideal for SaaS apps that rely on dynamic forms.

• Form builder + automatic API backend
• Supports Angular, React, Vue
• Role-based access, PDF exports

Best for: complex, backend-integrated workflows

🦙 Alpaca Forms#

A developer-centric library to render forms from JSON schema. No GUI builder, but very flexible.

• Schema-driven (JSON)
• Template support (Bootstrap, jQuery UI)
• Purely client-side rendering

Best for: static sites, custom JS-heavy apps

📊 Formbricks#

An open-source alternative to Typeform/Qualtrics focused on feedback forms, surveys, and in-app micro-surveys.

• One-question-per-screen format
• Slack/Zapier integrations
• Self-host or use their cloud

Best for: user research, embedded feedback, NPS

⚙️ Shadcn Form Builder (hasanharman)#

A polished, React-based drag-and-drop builder using Shadcn/UI and Zod. Developer-first, no backend built-in.

• Uses Tailwind + Radix UI
• Outputs clean React code
• Real-time builder interface

Best for: teams already using React/Next.js + Shadcn

🧩 Better Stack Form Builder Plugin (for @btst/stack)#

If you're building on Better Stack, the Form Builder plugin is a powerful, fully-integrated drag-and-drop form solution. Built with modern dev experience in mind, it gives teams a polished admin UI and full programmatic control.

✅ Highlights:#

• Drag-and-drop builder with live preview
• JSON Schema-based storage
• Frontend rendering by slug via <FormRenderer />
• Submission tracking with IP/user-agent
• Auth, rate limiting, and backend hooks

📦 Minimal setup:#

// Register backend plugin
formBuilder: formBuilderBackendPlugin({
  hooks: {
    onBeforeListForms: async (ctx) => {
      const session = await getSession(ctx.headers)
      return session?.user?.isAdmin === true
    }
  }
})

// Render public form
<FormRenderer slug="contact-us" onSuccess={() => toast("Submitted!")} />

🔄 Built on JSON Schema, the Better Stack Form Builder gives you full control over validation, storage, and customization — while providing a smooth editing experience for non-devs.

Why Better Stack’s Form Builder Plugin Stands Out#

If your team is building full stack apps with Better Stack, the Form Builder plugin provides a perfect balance:

• ✅ Developer control via JSON Schema, hooks, and headless APIs
• ✅ Editor-friendly UI with drag-and-drop, live preview, and field options
• ✅ First-class integration with Better Stack plugins and auth system
• ✅ Production-ready out of the box — rate limiting, spam filtering, CRM/webhook integrations

And because it's part of Better Stack’s plugin system, you can:

• Render forms dynamically via route slug
• Handle submissions securely with lifecycle hooks
• Extend the UI with custom field components

No need for an external SaaS — you can own the experience end-to-end, from form creation to data handling.

Want to see it in action? View the demo plugin

Wrapping Up#

Visual form builders are no longer just a convenience — they’re a competitive edge. For developers and agencies, they mean:

• Less time on boilerplate
• More time for what matters
• Faster iteration with clients

Open source options like Better Stack’s Form Builder, Budibase, and Form.io put control back in your hands. Whether you’re looking to improve internal workflows or build stunning client experiences, there’s a visual builder ready to fit into your stack.

Want to try Better Stack’s form builder? 👉 Start here