head to head · open source
Open WebUI vs sim
Open WebUI has 157,575 GitHub stars, 22,923 forks, 294 open issues and last shipped yesterday. sim has 29,974 stars, 3,879 forks, 336 open issues and last shipped yesterday. Open WebUI leads on adoption by 426% (157,575 vs 29,974 stars). Open WebUI is written in Python under a custom or non-standard licence; sim is written in TypeScript under Apache-2.0. Open WebUI has attracted 15% as many forks as stars, sim 13%. sim 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 | sim | |
|---|---|---|
| GitHub stars | ★ 158K | ★ 30K |
| License | Custom / other | Apache-2.0 |
| Written in | Python | TypeScript |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 23K | ⑂ 3.9K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Open WebUI if
- You weight community size — 158K 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 sim if
- You want the sim feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches TypeScript
- You evaluated both and sim 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 sim
A workspace to build, deploy and manage AI agents and workflows. Quickstart Cloud hosted: sim.ai Self hosted Open Desktop: macOS macOS 12+, Apple Silicon and Intel. See the desktop docs to point it at a self hosted deployment. Capabilities Connect 1,000+ integrations and every major LLM Add Slack, Notion, HubSpot, Salesforce, databases, and more Build agents visually, conversationally, or with code Ingest files, knowledge bases, and structured table data Monitor runs, logs, schedules, and workflow activity One workspace, every surface Chat and workflows are just the start — tables, files, and knowledge all live…
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Frequently asked questions
Is Open WebUI or sim more popular?
Open WebUI has 157,575 GitHub stars and sim has 29,974. Open WebUI has the larger community by that measure.
Are Open WebUI and sim free?
Both are open source. Open WebUI has no licence declared in this registry, and sim is licensed under Apache-2.0. Both are free to self-host.
What is the difference between Open WebUI and sim?
Open WebUI is written in Python and sim 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, Open WebUI or sim?
Choose Open WebUI if you want the larger community (157,575 stars) or its Custom / other licence terms. Choose sim if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.