Comparison
FastChat vs CTranslate2
Verdict
Pick FastChat when fastChat is primarily Python; CTranslate2 is C++; pick CTranslate2 when cTranslate2 is primarily C++; FastChat is Python.
Markdown twin · FastChat alternatives · CTranslate2 alternatives
GraphCanon updated today
vs
Trust & integrity
| Signal | FastChat | CTranslate2 |
|---|---|---|
| Maintenance | Steady (71d since push) As of today · github_public_v1 | Active (8d 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 |
Tagline
- FastChat
- An open platform for training, serving, and evaluating large language models
- CTranslate2
- Fast inference engine for Transformer models
Stars
- FastChat
- 39k
- CTranslate2
- 4.6k
Forks
- FastChat
- 4.8k
- CTranslate2
- 498
Open issues
- FastChat
- 1.0k
- CTranslate2
- 271
Language
- FastChat
- Python
- CTranslate2
- C++
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
- CTranslate2
- -
Persona
- FastChat
- -
- CTranslate2
- -
Runtime
- FastChat
- -
- CTranslate2
- -
License
- FastChat
- Apache-2.0
- CTranslate2
- MIT
Last pushed
- FastChat
- May 1, 2026
- CTranslate2
- Jul 3, 2026
Categories
- FastChat
- Model Training, LLM Frameworks, Evaluation & Observability, Inference & Serving
- CTranslate2
- Model Training, Inference & Serving
Trust and health
Maintenance
- FastChat
- Steady (60%)
- CTranslate2
- Active (82%)
Days since push
- FastChat
- 71d
- CTranslate2
- 8d
Open issues (now)
- FastChat
- 1.0k
- CTranslate2
- 271
Full report
- FastChat
- Trust report
- CTranslate2
- Trust report
Shared compatibility
- Python · FastChat: Python runtime · CTranslate2: Python runtime
Choose FastChat if…
- FastChat is primarily Python; CTranslate2 is C++.
- License: FastChat is Apache-2.0, CTranslate2 is MIT.
- 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.
Choose CTranslate2 if…
- CTranslate2 is primarily C++; FastChat is Python.
- License: CTranslate2 is MIT, FastChat is Apache-2.0.
- Tags unique to CTranslate2: avx, deep-learning, cpp, cuda.
When NOT to use CTranslate2
- 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.
Explore
Sources
Every stat on this page traces to a dated GitHub sync, license file, enrichment field, or trust scan.
- GitHub stars (lm-sys/FastChat) · observed Jul 11, 2026
- GitHub forks (lm-sys/FastChat) · observed Jul 11, 2026
- Last push (lm-sys/FastChat) · observed May 1, 2026
- License file (Apache-2.0) · observed Jul 11, 2026
- Decision facts (enrichment) · observed Jul 11, 2026
- Trust scan (lockfile / OSV) · observed Jul 11, 2026
- GitHub stars (OpenNMT/CTranslate2) · observed Jul 11, 2026
- GitHub forks (OpenNMT/CTranslate2) · observed Jul 11, 2026
- Last push (OpenNMT/CTranslate2) · observed Jul 3, 2026
- License file (MIT) · observed Jul 11, 2026
- Trust scan (lockfile / OSV) · observed Jul 11, 2026
GitHub stars on cards: FastChat 39k · CTranslate2 4.6k (synced Jul 11, 2026).
Common questions
- What is the difference between FastChat and CTranslate2?
- FastChat: An open platform for training, serving, and evaluating large language models. CTranslate2: Fast inference engine for Transformer models. See the comparison table for live GitHub stats and shared categories.
- When should I choose FastChat over CTranslate2?
- Choose FastChat over CTranslate2 when FastChat is primarily Python; CTranslate2 is C++; License: FastChat is Apache-2.0, CTranslate2 is MIT; 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 CTranslate2 over FastChat?
- Choose CTranslate2 over FastChat when CTranslate2 is primarily C++; FastChat is Python; License: CTranslate2 is MIT, FastChat is Apache-2.0; Tags unique to CTranslate2: avx, deep-learning, cpp, cuda.
- 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 CTranslate2?
- 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 CTranslate2 more popular on GitHub?
- FastChat has more GitHub stars (39,490 vs 4,566). Stars measure visibility, not whether either tool fits your constraints.
- Are FastChat and CTranslate2 open source?
- Yes - both are open-source projects on GitHub (FastChat: Apache-2.0, CTranslate2: MIT).
- Where can I find alternatives to FastChat or CTranslate2?
- GraphCanon lists graph-backed alternatives at FastChat alternatives and CTranslate2 alternatives (FastChat markdown twin, CTranslate2 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 CTranslate2?
- FastChat: Steady. CTranslate2: 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 CTranslate2?
- GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: FastChat trust report; CTranslate2 trust report.