head to head · open source
LibreChat vs sim
LibreChat has 44,418 GitHub stars, 9,122 forks, 732 open issues and last shipped today. sim has 29,680 stars, 3,843 forks, 336 open issues and last shipped today. LibreChat leads on adoption by 50% (44,418 vs 29,680 stars). LibreChat is written in TypeScript under MIT; sim is written in TypeScript under Apache-2.0. LibreChat has attracted 21% as many forks as stars, sim 13%. LibreChat was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 4 topic tags (ai, anthropic, deepseek, gemini), 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
| LibreChat | sim | |
|---|---|---|
| GitHub stars | ★ 44K | ★ 30K |
| License | MIT | Apache-2.0 |
| Written in | TypeScript | TypeScript |
| Last push | 2026-09-20 | 2026-09-20 |
| Forks | ⑂ 9.1K | ⑂ 3.8K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick LibreChat if
- You weight community size — 44K stars and counting
- You want the MIT license terms
- Your stack matches TypeScript
- 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 LibreChat
LibreChat is an open source, self hostable chat interface designed as an enhanced ChatGPT clone. It unifies access to multiple AI models—including OpenAI, Anthropic, Google Gemini, DeepSeek, Mistral, AWS Bedrock, Azure OpenAI, and others—within a single web application. Built in TypeScript, it supports real time streaming, multi model switching, and advanced agent workflows while providing features like message search, artifacts, code interpreter, and secure multi user authentication.
read the full LibreChat overview →
About sim
Sim is an open source collaborative workspace for building, deploying, and monitoring AI agents and workflows. It lives in the TypeScript ecosystem and is distributed under the Apache 2.0 license, with a repository that has accumulated roughly 29,600 stars and 3,800 forks over its two year history. The project positions itself as a single surface where chat, workflows, tables, files, and knowledge coexist, whether accessed through a browser or a desktop application for macOS.
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Frequently asked questions
Is LibreChat or sim more popular?
LibreChat has 44,418 GitHub stars and sim has 29,680. LibreChat has the larger community by that measure.
Are LibreChat and sim free?
Both are open source. LibreChat is licensed under MIT and sim under Apache-2.0. Neither carries a licence fee.
What is the difference between LibreChat and sim?
LibreChat is written in TypeScript 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, LibreChat or sim?
Choose LibreChat if you want the larger community (44,418 stars) or its MIT licence terms. Choose sim if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.