---
title: Feature Comparison
description: OpenUI vs json-render (Vercel), A2UI (Google), and CopilotKit OpenGenerativeUI.
---

# The Generative UI Landscape

**Four frameworks. Which one ships to production?**

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## At a Glance

|                            | **[OpenUI](https://github.com/thesysdev/openui)** | **[json-render](https://github.com/vercel-labs/json-render)** (Vercel) | **[A2UI](https://github.com/google/A2UI)** (Google) | **[CopilotKit OpenGenUI](https://github.com/CopilotKit/OpenGenerativeUI)** |
| -------------------------- | ------------------------------------------------- | ---------------------------------------------------------------------- | --------------------------------------------------- | -------------------------------------------------------------------------- |
| **Tokens**                 | **1x**                                            | 3x                                                                     | 3x                                                  | 4x                                                                         |
| **Latency (60 tok/s)**     | **4.9s**                                          | 14.2s                                                                  | 14.2s                                               | ~20s                                                                       |
| **Streaming**              | Yes                                               | Yes                                                                    | Yes                                                 | Partial                                                                    |
| **Consistent output**      | Yes                                               | Yes                                                                    | Yes                                                 | No                                                                         |
| **Design system**          | Yes                                               | Yes                                                                    | Yes                                                 | No                                                                         |
| **Components**             | Library + custom                                  | Library + custom                                                       | Custom only                                         | None                                                                       |
| **Built-in data fetching** | Yes                                               | No                                                                     | No                                                  | No                                                                         |
| **Chat UI included**       | Yes                                               | No                                                                     | No                                                  | Yes                                                                        |
| **Multi-platform**         | Web, mobile, email                                | Web, mobile, PDF, email, video                                         | Web, iOS, Android                                   | Web                                                                        |
| **Security risk**          | Minimal                                           | Minimal                                                                | Minimal                                             | Medium                                                                     |
| **License**                | MIT                                               | Apache 2.0                                                             | Apache 2.0                                          | MIT                                                                        |

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## Best For

- **Data-driven chat UIs and dashboards** → OpenUI
- **One UI across web, mobile, PDF and email** → OpenUI
- **Multi-agent systems across iOS, Android, and web** → OpenUI
- **Creative one-off visuals (animations, generative art)** → CopilotKit OpenGenUI
