gym

A toolkit for developing and comparing reinforcement learning algorithms.

DecliningOpen SourceLow lock-in

Pricing

Free tier

Flat rate

Adoption

Cooling

License

Open Source

Data freshness

Aging · Jun 8, 2026

Overview

What is gym?

Gym is a toolkit for developing and comparing reinforcement learning algorithms. It provides a standard API to interact with environments, making it easier to test different RL methods across various tasks.

Key differentiator

Gym provides a standardized and extensible framework for developing, testing, and comparing reinforcement learning algorithms across various environments.

Capability profile

Capability Radar

Ease of StartEcosystemValueMaturityFlexibilityScale Ready

Honest assessment

Strengths & Weaknesses

↑ Strengths

Standardized API for reinforcement learning environmentsmedium

Wide range of pre-built environments for testing algorithmsmedium

Easy to extend with custom environmentsmedium

↓ 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 support for non-standard environmentshigh

Custom environment integration requires significant effort and documentation is sparse on this topic

Performance bottlenecks in large-scale deploymentsmedium

Gym's architecture can lead to performance issues when scaling up the number of parallel environments

Fit analysis

Who is it for?

✓ Best for

Researchers looking to benchmark their reinforcement learning algorithms against standard environments

Developers who need a consistent API for interacting with various reinforcement learning environments

✕ Not a fit for

Projects requiring real-time interaction with physical systems (due to its local nature)

Teams needing cloud-based solutions for large-scale RL training

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 gym

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

View Setup Guide →