Gymnasium

A library for developing and comparing reinforcement learning algorithms.

EstablishedOpen SourceLow lock-in

Pricing

Free tier

Flat rate

Adoption

Rising

License

Open Source

Data freshness

Verified · Jul 16, 2026

Overview

What is Gymnasium?

Gymnasium is a successor to OpenAI Gym, providing a framework for creating environments to test and compare reinforcement learning algorithms. It's essential for researchers and developers working on AI-driven decision-making systems.

Key differentiator

Gymnasium offers a community-driven, improved version of OpenAI Gym, focusing on robustness and extensibility in reinforcement learning environments.

Capability profile

Capability Radar

Ease of StartEcosystemValueMaturityFlexibilityScale Ready

Honest assessment

Strengths & Weaknesses

↑ Strengths

Successor to OpenAI Gym, with improved features and support.medium

Extensive library of environments for testing reinforcement learning algorithms.medium

Community-driven development and maintenance.medium

↓ Weaknesses

Steep learning curve for non-Python developershigh

API requires Python-specific patterns, TypeScript SDK is community-maintained

Frequent breaking changes between versionsmedium

v0.1 to v0.2 migration required rewriting chain definitions

Limited documentation for advanced use caseshigh

Core documentation focuses on basic usage, lacks detailed guides for complex scenarios

Performance bottlenecks in large-scale simulationsmedium

Not optimized for real-time or high-frequency reinforcement learning tasks

Fit analysis

Who is it for?

✓ Best for

Academics and researchers who need a robust framework for testing RL algorithms.

Developers working on projects that require reinforcement learning environments.

✕ Not a fit for

Projects requiring real-time interaction with physical systems (Gymnasium is more suited for simulation).

Applications where the overhead of setting up an environment outweighs the benefits.

Cost structure

Pricing

Free Tier

Available

Open source — free to use

Starts at

$0

Model

Flat rate

Enterprise

None

Performance benchmarks

How Fast Is It?

Ecosystem

Relationships

Next step

Get Started with Gymnasium

Step-by-step setup guide with code examples and common gotchas.

View Setup Guide →