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

# FastChat vs pinferencia

*GraphCanon updated Jul 11, 2026*

## Verdict

Pick FastChat when tags unique to FastChat: chatbots, distributed serving, evaluation system, large-language-models; pick pinferencia when tags unique to pinferencia: ai, artificial-intelligence, computer-vision, data-science.

[FastChat](https://github.com/lm-sys/FastChat) reports 39k GitHub stars, 4.8k forks, and 1.0k open issues, last pushed May 1, 2026. [pinferencia](https://pinferencia.underneathall.app) has 543 stars, 83 forks, and 17 open issues, last pushed Feb 14, 2023. Figures are from public GitHub metadata via [FastChat's repository](https://github.com/lm-sys/FastChat) and [pinferencia's repository](https://github.com/underneathall/pinferencia).

| | [FastChat](/tools/lm-sys-fastchat.md) | [pinferencia](/tools/underneathall-pinferencia.md) |
| --- | --- | --- |
| Tagline | An open platform for training, serving, and evaluating large language models | Python + Inference - Model Deployment library in Python. Simplest model inference server ever. |
| Stars | 39,490 | 543 |
| Forks | 4,788 | 83 |
| Open issues | 1,027 | 17 |
| 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 | Computer Vision, Inference & Serving, Model Training |

## Trust and health

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

| | [FastChat](/tools/lm-sys-fastchat.md) | [pinferencia](/tools/underneathall-pinferencia.md) |
| --- | --- | --- |
| Maintenance | Steady (60%) | Dormant (18%) |
| Days since push | 71d | 1242d |
| Open issues (now) | 1.0k | 17 |
| Security scan | No lockfile | 160 low (160 low) |
| Full report | [trust report](/tools/lm-sys-fastchat/trust.md) | [trust report](/tools/underneathall-pinferencia/trust.md) |

## Shared compatibility

- **Python**: [FastChat](/tools/lm-sys-fastchat.md) - Python runtime; [pinferencia](/tools/underneathall-pinferencia.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 Evaluation & Observability, LLM Frameworks.
- - You are looking to train and evaluate state-of-the-art models such as Vicuna or MT-Bench.

### Choose pinferencia if…

- Tags unique to pinferencia: ai, artificial-intelligence, computer-vision, data-science.
- Also covers Computer Vision.
- Leaner open-issue backlog (17).

## 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 pinferencia

- Last GitHub push was 1243 days ago (dormant maintenance, Feb 14, 2023). Validate activity before betting a new project on pinferencia.
- Inference & Serving: Self-hosting rarely beats a hosted API on cost until you have steady, high-volume traffic.
- Model Training: Try prompting and RAG first; fine-tuning is the answer to style/format, not missing knowledge.

## Common questions

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

FastChat: An open platform for training, serving, and evaluating large language models. pinferencia: Python + Inference - Model Deployment library in Python. Simplest model inference server ever.. See the comparison table for live GitHub stats and shared categories.

### When should I choose FastChat over pinferencia?

Choose FastChat over pinferencia when Tags unique to FastChat: chatbots, distributed serving, evaluation system, large-language-models; Also covers Evaluation & Observability, LLM Frameworks; - You are looking to train and evaluate state-of-the-art models such as Vicuna or MT-Bench.

### When should I choose pinferencia over FastChat?

Choose pinferencia over FastChat when Tags unique to pinferencia: ai, artificial-intelligence, computer-vision, data-science; Also covers Computer Vision; Leaner open-issue backlog (17).

### 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 pinferencia?

Last GitHub push was 1243 days ago (dormant maintenance, Feb 14, 2023). Validate activity before betting a new project on pinferencia. Inference & Serving: Self-hosting rarely beats a hosted API on cost until you have steady, high-volume traffic. Model Training: Try prompting and RAG first; fine-tuning is the answer to style/format, not missing knowledge.

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

FastChat has more GitHub stars (39,490 vs 543). Stars measure visibility, not whether either tool fits your constraints.

### Are FastChat and pinferencia open source?

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

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

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

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

FastChat: Steady. pinferencia: 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 pinferencia?

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