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

# FastChat vs garak

*GraphCanon updated Jul 11, 2026*

## Verdict

Pick FastChat when tags unique to FastChat: chatbots, distributed serving, evaluation system, large-language-models; pick garak when tags unique to garak: ai, llm-evaluation, llm-security, 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. [garak](https://discord.gg/uVch4puUCs) has 8.4k stars, 1.1k forks, and 367 open issues, last pushed Jul 10, 2026. Figures are from public GitHub metadata via [FastChat's repository](https://github.com/lm-sys/FastChat) and [garak's repository](https://github.com/NVIDIA/garak).

| | [FastChat](/tools/lm-sys-fastchat.md) | [garak](/tools/nvidia-garak.md) |
| --- | --- | --- |
| Tagline | An open platform for training, serving, and evaluating large language models | the LLM vulnerability scanner |
| Stars | 39,490 | 8,400 |
| Forks | 4,788 | 1,079 |
| Open issues | 1,027 | 367 |
| Language | Python | Python |
| 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 | Apache-2.0 |
| Categories | Evaluation & Observability, Inference & Serving, LLM Frameworks, Model Training | Evaluation & Observability, LLM Frameworks, Vector Databases |

## Trust and health

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

| | [FastChat](/tools/lm-sys-fastchat.md) | [garak](/tools/nvidia-garak.md) |
| --- | --- | --- |
| Maintenance | Steady (60%) | Very active (96%) |
| Days since push | 71d | 1d |
| Open issues (now) | 1.0k | 367 |
| Security scan | No lockfile | 54 low (54 low) |
| Full report | [trust report](/tools/lm-sys-fastchat/trust.md) | [trust report](/tools/nvidia-garak/trust.md) |

## Shared compatibility

- **Python**: [FastChat](/tools/lm-sys-fastchat.md) - Python runtime; [garak](/tools/nvidia-garak.md) - Python runtime

## 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…

- Tags unique to FastChat: chatbots, distributed serving, evaluation system, large-language-models.
- Also covers Inference & Serving, Model Training.
- - You are looking to train and evaluate state-of-the-art models such as Vicuna or MT-Bench.

### Choose garak if…

- Tags unique to garak: ai, llm-evaluation, llm-security, python.
- Also covers Vector Databases.
- More recently updated (last pushed Jul 10, 2026).

## 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 garak

- Evaluation & Observability: Defer heavyweight eval infra only until you have real traffic - never skip it once users depend on answers.
- LLM Frameworks: Avoid a framework for a single prompt-and-retrieve call; the abstraction can cost more than it saves.
- Vector Databases: Don't reach for a dedicated vector DB under ~100k vectors; pgvector on your existing Postgres is simpler to operate.

## Common questions

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

FastChat: An open platform for training, serving, and evaluating large language models. garak: the LLM vulnerability scanner. See the comparison table for live GitHub stats and shared categories.

### When should I choose FastChat over garak?

Choose FastChat over garak when Tags unique to FastChat: chatbots, distributed serving, evaluation system, large-language-models; Also covers Inference & Serving, Model Training; - You are looking to train and evaluate state-of-the-art models such as Vicuna or MT-Bench.

### When should I choose garak over FastChat?

Choose garak over FastChat when Tags unique to garak: ai, llm-evaluation, llm-security, python; Also covers Vector Databases; More recently updated (last pushed Jul 10, 2026).

### 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 garak?

Evaluation & Observability: Defer heavyweight eval infra only until you have real traffic - never skip it once users depend on answers. LLM Frameworks: Avoid a framework for a single prompt-and-retrieve call; the abstraction can cost more than it saves. Vector Databases: Don't reach for a dedicated vector DB under ~100k vectors; pgvector on your existing Postgres is simpler to operate.

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

FastChat has more GitHub stars (39,490 vs 8,400). Stars measure visibility, not whether either tool fits your constraints.

### Are FastChat and garak open source?

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

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

GraphCanon lists graph-backed alternatives at [FastChat alternatives](/tools/lm-sys-fastchat/alternatives) and [garak alternatives](/tools/nvidia-garak/alternatives) ([FastChat markdown twin](/tools/lm-sys-fastchat/alternatives.md), [garak markdown twin](/tools/nvidia-garak/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-nvidia-garak.md) mirrors this page for agents and LLM crawlers, with the same stats table and FAQ answers.

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

FastChat: Steady. garak: Very active. 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 garak?

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