LLMTest
LLMTest is an open-source, MIT-licensed Python library designed to facilitate robust testing of Large Language Models (LLMs).
Our verdict
Who it's for
Test your AI outputs like you test your code with pytest for LLMs.
Who should look elsewhere
Requires Python knowledge and familiarity with pytest
Pros
- +Leverages familiar pytest framework for easy adoption by Python developers
- +Reduces testing costs by avoiding LLM judge calls for most assertions
- +Provides robust validation for complex agent behaviors
- +Open-source and MIT licensed, promoting community contributions and flexibility
- +Supports a wide range of popular LLM providers
Cons
- −Requires Python knowledge and familiarity with pytest
- −Newer tool (v0.1.0) may have evolving features or limited community resources compared to mature tools
Key features
- ✓Pytest integration for LLM testing
- ✓22+ built-in assertions (text, performance, agent, composable)
- ✓Multi-provider support (OpenAI, Anthropic, Ollama, DeepSeek, Gemini, Mistral)
- ✓Zero LLM calls for most assertions (deterministic and instant)
- ✓Pydantic integration for auto-validation and JSON serialization
- ✓Agent testing capabilities (tool call validation, loop detection, call ordering)
- ✓Built-in retry support for non-deterministic outputs
Pricing
| Plan | Price | Billing | Notes |
|---|---|---|---|
| Open Source | — | month | MIT licensed; Pytest for LLMs; OpenAI, Claude, Ollama, DeepSeek, Gemini, Mistral support |