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Comparison

FastChat vs dia

Verdict

Pick FastChat when tags unique to FastChat: evaluation system, large-language-models, chatbots, distributed serving; pick dia when tags unique to dia: ai, text-to-speech, python, open-weight.

Markdown twin · FastChat alternatives · dia alternatives

GraphCanon updated today

FastChat logo

FastChat

lm-sys/FastChat

★ 39kpushed May 1, 2026
vs
dia logo

dia

nari-labs/dia

★ 19kpushed Nov 19, 2025

Trust & integrity

SignalFastChatdia
Maintenance
Steady (71d since push)
As of today · github_public_v1
Slowing (233d since push)
As of today · github_public_v1
Provenance
Not a fork · Organization account
As of today · github_public_v1
Not a fork · Organization account
As of today · github_public_v1
Security (OSV)
No lockfile
As of today · none
No lockfile
As of today · none
FastChat trust reportdia trust reportTrust methodology

Tagline

FastChat
An open platform for training, serving, and evaluating large language models
dia
A TTS model capable of generating ultra-realistic dialogue in one pass.

Stars

FastChat
39k
dia
19k

Forks

FastChat
4.8k
dia
1.7k

Open issues

FastChat
1.0k
dia
91

Language

FastChat
Python
dia
Python

Adopt for

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
dia
-

Persona

FastChat
-
dia
-

Runtime

FastChat
-
dia
-

License

FastChat
Apache-2.0
dia
Apache-2.0

Last pushed

FastChat
May 1, 2026
dia
Nov 19, 2025

Categories

FastChat
Model Training, LLM Frameworks, Inference & Serving, Evaluation & Observability
dia
Model Training, Speech & Audio, Inference & Serving

Trust and health

Maintenance

FastChat
Steady (60%)
dia
Slowing (36%)

Days since push

FastChat
71d
dia
233d

Open issues (now)

FastChat
1.0k
dia
91

Full report

FastChat
Trust report
dia
Trust report

Shared compatibility

  • Python · FastChat: Python runtime · dia: Python runtime

Choose FastChat if…

  • 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 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.
GitHubDetails

Choose dia if…

  • Tags unique to dia: ai, text-to-speech, python, open-weight.
  • Also covers Speech & Audio.
  • Leaner open-issue backlog (91).

When NOT to use dia

  • Last GitHub push was 234 days ago (slowing maintenance, Nov 19, 2025). Validate activity before betting a new project on dia.
  • 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.
GitHubDetails

Explore

FastChat trust report →dia trust report →Model Training category →LLM Frameworks category →Inference & Serving category →Evaluation & Observability category →Speech & Audio category →All comparisonsStack workflowsTrending tools

Sources

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

GitHub stars on cards: FastChat 39k · dia 19k (synced Jul 11, 2026).

Common questions

What is the difference between FastChat and dia?
FastChat: An open platform for training, serving, and evaluating large language models. dia: A TTS model capable of generating ultra-realistic dialogue in one pass.. See the comparison table for live GitHub stats and shared categories.
When should I choose FastChat over dia?
Choose FastChat over dia when 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 dia over FastChat?
Choose dia over FastChat when Tags unique to dia: ai, text-to-speech, python, open-weight; Also covers Speech & Audio; Leaner open-issue backlog (91).
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 dia?
Last GitHub push was 234 days ago (slowing maintenance, Nov 19, 2025). Validate activity before betting a new project on dia. 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 dia more popular on GitHub?
FastChat has more GitHub stars (39,490 vs 19,340). Stars measure visibility, not whether either tool fits your constraints.
Are FastChat and dia open source?
Yes - both are open-source projects on GitHub (FastChat: Apache-2.0, dia: Apache-2.0).
Where can I find alternatives to FastChat or dia?
GraphCanon lists graph-backed alternatives at FastChat alternatives and dia alternatives (FastChat markdown twin, dia 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, FastChat or dia?
FastChat: Steady. dia: 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 FastChat and dia?
GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: FastChat trust report; dia trust report.