---
title: "FastChat vs TNN"
type: "comparison"
canonical_url: "https://www.graphcanon.com/compare/lm-sys-fastchat-vs-tencent-tnn"
tools: ["lm-sys-fastchat", "tencent-tnn"]
---

# FastChat vs TNN

*GraphCanon updated Jul 11, 2026*

## Verdict

Pick FastChat when fastChat is primarily Python; TNN is C++; pick TNN when tNN is primarily C++; FastChat is Python.

[FastChat](https://github.com/lm-sys/FastChat) reports 39k GitHub stars, 4.8k forks, and 1.0k open issues, last pushed May 1, 2026. [TNN](https://github.com/Tencent/TNN) has 4.6k stars, 773 forks, and 318 open issues, last pushed May 9, 2025. Figures are from public GitHub metadata via [FastChat's repository](https://github.com/lm-sys/FastChat) and [TNN's repository](https://github.com/Tencent/TNN).

| | [FastChat](/tools/lm-sys-fastchat.md) | [TNN](/tools/tencent-tnn.md) |
| --- | --- | --- |
| Tagline | An open platform for training, serving, and evaluating large language models | TNN: developed by Tencent Youtu Lab and Guangying Lab, a uniform deep learning inference framework for mobile、desktop and server. TNN is distinguished by several outstanding features, including its cr |
| Stars | 39,490 | 4,640 |
| Forks | 4,788 | 773 |
| Open issues | 1,027 | 318 |
| Language | Python | C++ |
| Adopt for | FastChat is a comprehensive open platform for managing large language models (LLMs) that includes capabilities for training, serving, evaluating, and comparing chatbot models via web UIs and RESTful APIs. It powers ChatB | - |
| Persona | - | - |
| Runtime | - | - |
| License | Apache-2.0 | Other |
| Categories | Model Training, LLM Frameworks, Inference & Serving, Evaluation & Observability | Model Training, Computer Vision, Inference & Serving |

## Trust and health

_Sourced signals - not a safety guarantee. No winner column._

| | [FastChat](/tools/lm-sys-fastchat.md) | [TNN](/tools/tencent-tnn.md) |
| --- | --- | --- |
| Maintenance | Steady (60%) | Dormant (18%) |
| Days since push | 71d | 428d |
| Open issues (now) | 1.0k | 318 |
| Full report | [trust report](/tools/lm-sys-fastchat/trust.md) | [trust report](/tools/tencent-tnn/trust.md) |

## Decision facts: FastChat

- **Adopt for:** FastChat is a comprehensive open platform for managing large language models (LLMs) that includes capabilities for training, serving, evaluating, and comparing chatbot models via web UIs and RESTful APIs. It powers ChatB

## Choose when

### Choose FastChat if…

- FastChat is primarily Python; TNN is C++.
- License: FastChat is Apache-2.0, TNN is Other.
- Tags unique to FastChat: evaluation system, large-language-models, chatbots, distributed serving.
- Also covers LLM Frameworks, Evaluation & Observability.
- - You are looking to train and evaluate state-of-the-art models such as Vicuna or MT-Bench.

### Choose TNN if…

- TNN is primarily C++; FastChat is Python.
- License: TNN is Other, FastChat is Apache-2.0.
- Tags unique to TNN: deep-learning, ncnn, face-detection, mnn.
- Also covers Computer Vision.
- TNN ships Docker support for self-hosted deployment.

## When NOT to use FastChat

- - You require a proprietary or closed-source framework; FastChat is open-source under Apache-2.0 license and its use might be unsuitable for environments requiring proprietary solutions.
- - Your chatbot evaluation needs do not align with the types of data used in FastChat's datasets (e.g., human votes, MT-Bench evaluations).
- - You prefer a more user-friendly setup without the need to clone a repository and manually install dependencies; FastChat requires installation from source with additional steps for Rust and CMake on
- + Mac.

## When NOT to use TNN

- Last GitHub push was 429 days ago (dormant maintenance, May 9, 2025). Validate activity before betting a new project on TNN.
- Model Training: Try prompting and RAG first; fine-tuning is the answer to style/format, not missing knowledge.
- Inference & Serving: Self-hosting rarely beats a hosted API on cost until you have steady, high-volume traffic.

## Common questions

### What is the difference between FastChat and TNN?

FastChat: An open platform for training, serving, and evaluating large language models. TNN: TNN: developed by Tencent Youtu Lab and Guangying Lab, a uniform deep learning inference framework for mobile、desktop and server. TNN is distinguished by several outstanding features, including its cr. See the comparison table for live GitHub stats and shared categories.

### When should I choose FastChat over TNN?

Choose FastChat over TNN when FastChat is primarily Python; TNN is C++; License: FastChat is Apache-2.0, TNN is Other; Tags unique to FastChat: evaluation system, large-language-models, chatbots, distributed serving; Also covers LLM Frameworks, Evaluation & Observability; - You are looking to train and evaluate state-of-the-art models such as Vicuna or MT-Bench.

### When should I choose TNN over FastChat?

Choose TNN over FastChat when TNN is primarily C++; FastChat is Python; License: TNN is Other, FastChat is Apache-2.0; Tags unique to TNN: deep-learning, ncnn, face-detection, mnn; Also covers Computer Vision; TNN ships Docker support for self-hosted deployment.

### When should I avoid FastChat?

- You require a proprietary or closed-source framework; FastChat is open-source under Apache-2.0 license and its use might be unsuitable for environments requiring proprietary solutions. - Your chatbot evaluation needs do not align with the types of data used in FastChat's datasets (e.g., human votes, MT-Bench evaluations). - You prefer a more user-friendly setup without the need to clone a repository and manually install dependencies; FastChat requires installation from source with additional steps for Rust and CMake on + Mac.

### When should I avoid TNN?

Last GitHub push was 429 days ago (dormant maintenance, May 9, 2025). Validate activity before betting a new project on TNN. Model Training: Try prompting and RAG first; fine-tuning is the answer to style/format, not missing knowledge. Inference & Serving: Self-hosting rarely beats a hosted API on cost until you have steady, high-volume traffic.

### Is FastChat or TNN more popular on GitHub?

FastChat has more GitHub stars (39,490 vs 4,640). Stars measure visibility, not whether either tool fits your constraints.

### Are FastChat and TNN open source?

Yes - both are open-source projects on GitHub (FastChat: Apache-2.0, TNN: Other).

### Where can I find alternatives to FastChat or TNN?

GraphCanon lists graph-backed alternatives at [FastChat alternatives](/tools/lm-sys-fastchat/alternatives) and [TNN alternatives](/tools/tencent-tnn/alternatives) ([FastChat markdown twin](/tools/lm-sys-fastchat/alternatives.md), [TNN markdown twin](/tools/tencent-tnn/alternatives.md)), ranked by typed relationship edges rather than popularity votes.

### Is there a machine-readable version of this comparison?

Yes. The markdown twin at [this comparison](/compare/lm-sys-fastchat-vs-tencent-tnn.md) mirrors this page for agents and LLM crawlers, with the same stats table and FAQ answers.

### Which is better maintained, FastChat or TNN?

FastChat: Steady. TNN: Dormant. Compare maintenance labels, days since push, and release cadence in the trust section below - stars alone do not measure maintenance.

### Where are the full trust reports for FastChat and TNN?

GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: [FastChat trust report](/tools/lm-sys-fastchat/trust); [TNN trust report](/tools/tencent-tnn/trust).

---

**Machine-readable endpoints**

- JSON: [`/api/graphcanon/graph?tool=lm-sys-fastchat`](/api/graphcanon/graph?tool=lm-sys-fastchat)
- LLM index: [/llms.txt](/llms.txt)
- Full corpus: [/llms-full.txt](/llms-full.txt)

_GraphCanon - The knowledge graph for AI development. https://www.graphcanon.com/_
