Observability & MonitoringSchemathesis
Automated property-based testing for Open API / Swagger specs
- Status
- Generally available
- Last checked
- Aging · Sep 3, 2026
- License
- Open source
- Pricing
- Free tier · from $0
What it is
Schemathesis is a tool that automatically tests web applications built with Open API or Swagger specifications, ensuring they behave as expected according to their documentation.
Schemathesis stands out by providing automated property-based testing specifically tailored to applications built with OpenAPI / Swagger specifications, ensuring robust and consistent API behavior.
When it fits — and when it doesn’t
A good fit for
Developers working on RESTful services who need to ensure their APIs adhere strictly to OpenAPI or Swagger specifications.
Teams that want to automate the process of generating test cases based on API documentation.
Look elsewhere if
Projects where the API does not use OpenAPI or Swagger for its specification
Testing non-RESTful services (e.g., GraphQL APIs)
Known weaknesses
Each one links to the public issue, changelog or docs page it came from, where we have one.
- 01
Limited support for non-OpenAPI specifications
Primarily designed for Open API and Swagger, lacking comprehensive support for other specification formats like RAML or AsyncAPI
- 02
Performance issues with large APIs
Test generation and execution can become slow when dealing with extensive API specifications and complex schemas
What it does well
Automated property-based testing for Open API / Swagger specs
Generates test cases based on the schema
Detects inconsistencies between the spec and implementation
Pricing
- Free tier
- YesOpen source — free to use
- Paid from
- $0
- Model
- Flat rate
- Enterprise plan
- No
Pricing not independently confirmed — check the vendor’s page.
Performance benchmarks
How Fast Is It?
Set up Schemathesis
Setup steps, common gotchas and what to check after 30 days.