responses

A utility library for mocking out the requests Python library.

EstablishedOpen SourceLow lock-in

Pricing

Free tier

Flat rate

Adoption

Stable

License

Open Source

Data freshness

Aging · Jun 8, 2026

Overview

What is responses?

Responses is a utility library that allows developers to mock HTTP responses in their tests without needing an internet connection. It's particularly useful for testing code that interacts with external APIs or web services.

Key differentiator

Responses stands out as a lightweight, easy-to-use library specifically designed for mocking HTTP responses in Python tests, making it ideal for developers who need reliable and isolated testing conditions.

Capability profile

Capability Radar

Ease of StartEcosystemValueMaturityFlexibilityScale Ready

Honest assessment

Strengths & Weaknesses

↑ Strengths

Simplifies testing by mocking HTTP responsesmedium

Does not require an internet connection for testsmedium

Easy to use with popular Python testing frameworksmedium

↓ 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 and examples for advanced use caseshigh

Official docs lack comprehensive guides on complex scenarios like dynamic response generation

Small community support and slow issue resolutionmedium

GitHub issues often remain unresolved for extended periods, with limited activity from maintainers

Fit analysis

Who is it for?

✓ Best for

Developers who need to mock HTTP responses for testing purposes

Projects where internet connectivity is unreliable or unavailable during testing

Teams that require consistent and predictable test results without external dependencies

✕ Not a fit for

Scenarios requiring real-time interaction with live APIs

Testing environments where network behavior needs to be accurately simulated

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 responses

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

View Setup Guide →