head to head · open source
CopilotKit vs assistant-ui
CopilotKit has 37,403 GitHub stars, 4,640 forks, 295 open issues and last shipped today. assistant-ui has 12,194 stars, 1,183 forks, 207 open issues and last shipped today. CopilotKit leads on adoption by 207% (37,403 vs 12,194 stars). CopilotKit is written in TypeScript under MIT; assistant-ui is written in TypeScript under MIT. CopilotKit has attracted 12% as many forks as stars, assistant-ui 10%. CopilotKit was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (copilot), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| CopilotKit | assistant-ui | |
|---|---|---|
| GitHub stars | ★ 37K | ★ 12K |
| License | MIT | MIT |
| Written in | TypeScript | TypeScript |
| Last push | 2026-09-18 | 2026-09-18 |
| Forks | ⑂ 4.6K | ⑂ 1.2K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick CopilotKit if
- You weight community size — 37K stars and counting
- You want the MIT license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick assistant-ui if
- You want the assistant-ui feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches TypeScript
- You evaluated both and assistant-ui fits your workflow better
About CopilotKit
CopilotKit is a frontend SDK for building agent native applications and generative UI experiences. It provides tooling and protocols to connect AI agents—regardless of backend framework—to user interfaces across web, mobile, and messaging platforms. It lives in the agentic AI ecosystem, specifically targeting developers who need to embed intelligent assistants into products without rebuilding agent logic for each surface.
read the full CopilotKit overview →
About assistant-ui
assistant ui is an open source TypeScript and React library, released under the MIT licence, for building production grade AI chat experiences quickly, and it is aimed at frontend and full stack developers who need the user experience of ChatGPT inside their own React application.
read the full assistant-ui overview →
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Frequently asked questions
Is CopilotKit or assistant-ui more popular?
CopilotKit has 37,403 GitHub stars and assistant-ui has 12,194. CopilotKit has the larger community by that measure.
Are CopilotKit and assistant-ui free?
Both are open source. CopilotKit is licensed under MIT and assistant-ui under MIT. Neither carries a licence fee.
What is the difference between CopilotKit and assistant-ui?
CopilotKit is written in TypeScript and assistant-ui in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, CopilotKit or assistant-ui?
Choose CopilotKit if you want the larger community (37,403 stars) or its MIT licence terms. Choose assistant-ui if its feature set, stack or MIT licence fits better. Both are self-hostable.