Home/Compare/openchat vs FastChat

Comparison

openchat vs FastChat

Verdict

Pick openchat if a Python library for training large language models with imperfect data using transformers; pick FastChat if 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.

Markdown twin · openchat alternatives · FastChat alternatives

GraphCanon updated 2d

openchat logo

openchat

imoneoi/openchat

5.5kpushed Sep 13, 2024
vs
FastChat logo

FastChat

lm-sys/FastChat

40kpushed May 1, 2026

Trust & integrity

SignalopenchatFastChat
Maintenance
Dormant (703d since push)
As of 2d · github_public_v1
Slowing (98d since push)
As of 1w · github_public_v1
Provenance
Not a fork · Personal account
As of 2d · github_public_v1
Not a fork · Organization account
As of 1w · github_public_v1
OSV dependency advisories
No lockfile (source not queried)
As of 1mo · osv@v1
No lockfile (source not queried)
As of 1mo · osv@v1
deps.dev advisories
Not queried
deps.dev@v1
Not queried
deps.dev@v1
OpenSSF Scorecard
Not queried
openssf-scorecard@v1
Not queried
openssf-scorecard@v1

Tagline

openchat
Advancing Open-source Language Models with Imperfect Data
FastChat
An open platform for training, serving, and evaluating large language models

Stars

openchat
5.5k
FastChat
40k

Forks

openchat
432
FastChat
4.8k

Open issues

openchat
137
FastChat
1.0k

Language

openchat
Python
FastChat
Python

Adopt for

openchat
A Python library for training large language models with imperfect data using transformers.
FastChat
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

openchat
-
FastChat
-

Runtime

openchat
-
FastChat
-

License

openchat
Apache-2.0
FastChat
Apache-2.0

Last pushed

openchat
Sep 13, 2024
FastChat
May 1, 2026

Categories

openchat
LLM Frameworks, Model Training
FastChat
Evaluation & Observability, Inference & Serving, LLM Frameworks, Model Training

Trust and health

Maintenance

openchat
Dormant (18%)
FastChat
Slowing (36%)

Days since push

openchat
703d
FastChat
98d

Open issues (now)

openchat
137
FastChat
1.0k

Stars delta

openchat
+2 (30d)
FastChat
Unknown

Open issues delta

openchat
+1 (30d)
FastChat
Unknown

Owner type

openchat
User
FastChat
Organization

Full report

openchat
Trust report
FastChat
Trust report

Choose openchat if…

  • Tags unique to openchat: apache license 2.0, cuda, open-source, pytorch.
  • You need to train models on datasets with noise or missing information
  • Leaner open-issue backlog (137).

When NOT to use openchat

  • If your dataset is clean and well-structured, reducing model inaccuracies
  • Projects that cannot depend on Apache License 2.0 or install PyTorch with CUDA support

Choose FastChat if…

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

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.

Explore

Sources

Every stat on this page traces to a dated GitHub sync, license file, enrichment field, or trust scan.

GitHub stars on cards: openchat 5.5k · FastChat 40k (synced Aug 17, 2026).

Common questions

What is the difference between openchat and FastChat?
openchat: Advancing Open-source Language Models with Imperfect Data. FastChat: An open platform for training, serving, and evaluating large language models. See the comparison table for live GitHub stats and shared categories.
When should I choose openchat over FastChat?
Choose openchat over FastChat when Tags unique to openchat: apache license 2.0, cuda, open-source, pytorch; You need to train models on datasets with noise or missing information; Leaner open-issue backlog (137).
When should I choose FastChat over openchat?
Choose FastChat over openchat when Tags unique to FastChat: chatbots, distributed-serving, evaluation system; Also covers Evaluation & Observability, Inference & Serving; - You are looking to train and evaluate state-of-the-art models such as Vicuna or MT-Bench.
When should I avoid openchat?
If your dataset is clean and well-structured, reducing model inaccuracies Projects that cannot depend on Apache License 2.0 or install PyTorch with CUDA support
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.
Is openchat or FastChat more popular on GitHub?
FastChat has more GitHub stars (39,517 vs 5,487). Stars measure visibility, not whether either tool fits your constraints.
Are openchat and FastChat open source?
Yes - both are open-source projects on GitHub (openchat: Apache-2.0, FastChat: Apache-2.0).
Where can I find alternatives to openchat or FastChat?
GraphCanon lists graph-backed alternatives at openchat alternatives and FastChat alternatives (openchat markdown twin, FastChat markdown twin), 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 mirrors this page for agents and LLM crawlers, with the same stats table and FAQ answers.
Which is better maintained, openchat or FastChat?
openchat: Dormant. FastChat: Slowing. 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 openchat and FastChat?
GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: openchat trust report; FastChat trust report.

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