Comparison
leva vs FastChat
Verdict
Pick leva when leva is primarily Ruby; FastChat is Python; pick FastChat when fastChat is primarily Python; leva is Ruby.
Markdown twin · leva alternatives · FastChat alternatives
GraphCanon updated today
Trust & integrity
| Signal | leva | FastChat |
|---|---|---|
| Maintenance | Steady (37d since push) As of today · github_public_v1 | Steady (71d since push) As of 1d · github_public_v1 |
| Provenance | Not a fork · Personal account As of today · github_public_v1 | Not a fork · Organization account As of 1d · github_public_v1 |
| Security (OSV) | No lockfile As of today · none | No lockfile As of 1d · none |
Tagline
- leva
- LLM Evaluation Framework for Rails apps to be used with production data.
- FastChat
- An open platform for training, serving, and evaluating large language models
Stars
- leva
- 141
- FastChat
- 39k
Forks
- leva
- 7
- FastChat
- 4.8k
Open issues
- leva
- 4
- FastChat
- 1.0k
Language
- leva
- Ruby
- FastChat
- Python
Adopt for
- leva
- -
- 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
- leva
- -
- FastChat
- -
Runtime
- leva
- -
- FastChat
- -
License
- leva
- MIT
- FastChat
- Apache-2.0
Last pushed
- leva
- Jun 3, 2026
- FastChat
- May 1, 2026
Categories
- leva
- Evaluation & Observability, LLM Frameworks
- FastChat
- Evaluation & Observability, Inference & Serving, LLM Frameworks, Model Training
Trust and health
Days since push
- leva
- 37d
- FastChat
- 71d
Open issues (now)
- leva
- 4
- FastChat
- 1.0k
Owner type
- leva
- User
- FastChat
- Organization
Full report
- leva
- Trust report
- FastChat
- Trust report
Choose leva if…
- leva is primarily Ruby; FastChat is Python.
- License: leva is MIT, FastChat is Apache-2.0.
- Tags unique to leva: llm, llm-evaluation, ruby, ruby-on-rails.
When NOT to use leva
- 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.
Choose FastChat if…
- FastChat is primarily Python; leva is Ruby.
- License: FastChat is Apache-2.0, leva is MIT.
- 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 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 (kieranklaassen/leva) · observed Jul 11, 2026
- GitHub forks (kieranklaassen/leva) · observed Jul 11, 2026
- Last push (kieranklaassen/leva) · observed Jun 3, 2026
- License file (MIT) · observed Jul 11, 2026
- Trust scan (lockfile / OSV) · observed Jul 11, 2026
- 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 on cards: leva 141 · FastChat 39k (synced Jul 11, 2026).
Common questions
- What is the difference between leva and FastChat?
- leva: LLM Evaluation Framework for Rails apps to be used with production 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 leva over FastChat?
- Choose leva over FastChat when leva is primarily Ruby; FastChat is Python; License: leva is MIT, FastChat is Apache-2.0; Tags unique to leva: llm, llm-evaluation, ruby, ruby-on-rails.
- When should I choose FastChat over leva?
- Choose FastChat over leva when FastChat is primarily Python; leva is Ruby; License: FastChat is Apache-2.0, leva is MIT; 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 avoid leva?
- 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.
- 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 leva or FastChat more popular on GitHub?
- FastChat has more GitHub stars (39,490 vs 141). Stars measure visibility, not whether either tool fits your constraints.
- Are leva and FastChat open source?
- Yes - both are open-source projects on GitHub (leva: MIT, FastChat: Apache-2.0).
- Where can I find alternatives to leva or FastChat?
- GraphCanon lists graph-backed alternatives at leva alternatives and FastChat alternatives (leva 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, leva or FastChat?
- leva: Steady. FastChat: Steady. 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 leva and FastChat?
- GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: leva trust report; FastChat trust report.