head to head · open source
Open WebUI vs Kai
Open WebUI has 157,498 GitHub stars, 22,901 forks, 294 open issues and last shipped yesterday. Kai has 1,330 stars, 211 forks, 127 open issues and last shipped 10 days ago. Open WebUI leads on adoption by 11,742% (157,498 vs 1,330 stars). Open WebUI is written in Python under a custom or non-standard licence; Kai is written in Kotlin under Apache-2.0. Open WebUI has attracted 15% as many forks as stars, Kai 16%. Open WebUI was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (ai), 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
| Open WebUI | Kai | |
|---|---|---|
| GitHub stars | ★ 157K | ★ 1.3K |
| License | Custom / other | Apache-2.0 |
| Written in | Python | Kotlin |
| Last push | 2026-11-02 | 2026-10-24 |
| Forks | ⑂ 23K | ⑂ 211 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Open WebUI if
- You weight community size — 157K stars and counting
- You want the Custom / other license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick Kai if
- You want the Kai feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Kotlin
- You evaluated both and Kai fits your workflow better
About Open WebUI
Open WebUI 👋 Open WebUI is a home for AI , a self hosted AI platform that's extensible , feature rich , user friendly, and built to run entirely offline . With support for Ollama and OpenAI compatible APIs , it gives you a powerful, provider agnostic interface for both local and cloud based models. Passionate about open source AI? Join our team → [!TIP] Looking for an Enterprise Plan? – Speak with Our Sales Team Today! For more information, be sure to check out our Open WebUI Documentation. Key Features of Open WebUI ⭐ 🚀 Effortless Setup : Install seamlessly via pip, uv, Docker, or Kubernetes (kubectl…
read the full Open WebUI overview →
About Kai
Kai 9000 An open source AI assistant with persistent memory that runs on Android, iOS, Windows, Mac, Linux, and Web . Website Documentation Sponsor: Atlas Cloud Installation Homebrew (macOS): AUR (Arch Linux): Winget (Windows): Direct Downloads AI That Builds Screens, Not Just Text Kai 9000's Interactive UI lets the AI generate full interactive screens — quizzes, dashboards, recipes, brainstorms, and more. Navigate by tapping buttons instead of scrolling through chat. Features Persistent memory — Kai remembers important details across conversations and uses them automatically Customizable soul — Define the AI's…
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Frequently asked questions
Is Open WebUI or Kai more popular?
Open WebUI has 157,498 GitHub stars and Kai has 1,330. Open WebUI has the larger community by that measure.
Are Open WebUI and Kai free?
Both are open source. Open WebUI has no licence declared in this registry, and Kai is licensed under Apache-2.0. Both are free to self-host.
What is the difference between Open WebUI and Kai?
Open WebUI is written in Python and Kai in Kotlin. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Open WebUI or Kai?
Choose Open WebUI if you want the larger community (157,498 stars) or its Custom / other licence terms. Choose Kai if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.