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APIs are the backbone of modern applications, enabling seamless communication between different services, from payment gateways in e-commerce apps to authentication systems in social platforms. API testing is essential to ensure these APIs function correctly, securely, and efficiently. Unlike UI testing, which focuses on how the application looks and behaves for the end user, API testing validates the underlying services logic, reliability, performance, and security.
Comparison of the 5 Best API Testing Tools
| Features |  | Apidog | ContextQA | vREST | Insomnia |
|---|---|---|---|---|---|
| Support for multiple protocols | REST, GraphQL | REST, GraphQL, WebSocket, gRPC | REST, GraphQL | REST | REST, GraphQL, gRPC, WebSocket |
| Request building and parameterization | GET, POST, PUT, DELETE, PATCH with variables | Yes | Only with data support | Only CRUD support and parameterization | Yes |
| Response validation | Status codes, headers, JSON schema, body content | Schema validation, assertions | Functional validation | Yes | Yes |
| Authentication and authorization | OAuth 2.0, JWT, API keys, Basic Auth, Bearer | Yes | OAuth 2.0, API key | Basic | Yes |
| Different environments support | Dev, staging, prod + variable sets | Yes | Yes | Yes | Yes |
| Automation | API Automation ready | Limited | Yes | Limited | Limited |
| Integrations | Jenkins, GitHub, GitLab, Azure DevOps, CircleCI, etc. | Git, Swagger / OpenAPI, Postman import/export | CI/CD tools, Slack, Jira | CI/CD pipelines, Jenkins, reporting tools | Git sync, Postman import/export, CLI integrations |
14 Best API Testing Tools in 2025
Here is the list of the top 16 best tools for API testing in 2025. You can choose yours based on your
organization′s requirements
Testsigma
Testsigma is an Agentic AI-powered test automation platform that simplifies Automated API testing for QA teams of all sizes. Its no-code approach and intelligent agents enable teams to validate APIs quickly and efficiently. Beyond APIs, Testsigma also supports web, mobile, desktop, browser, Salesforce, and ERP testing all in one platform. With self-healing tests, AI-powered test creation, reduced flakiness, a rich device lab, and cross-platform support, QA teams can unify their testing strategy.
Features of Testsigma
- Create and run tests without code – Build API requests in plain English, no scripting required.
- Supports all HTTP methods – GET, POST, PUT, PATCH, DELETE with headers and payloads.
- Easy response validation – Assert status codes, headers, response times, and schema validations.
- Data-driven testing – Run the same test across multiple datasets for broader coverage.
- Environment & variable management – Reuse variables across dev, staging, and prod environments.
- Authentication support – Seamlessly test secure APIs with OAuth 2.0, JWT, API keys, and Basic/Bearer auth.
- Chained requests – Pass outputs like tokens or IDs from one API call into another for end-to-end workflows.
- Test Management - Built-in test management features for organizing cases.
- CI/CD integration – Plug API tests into Jenkins, GitHub Actions, GitLab, or Azure DevOps pipelines.
Apidog
Apidog is an all-in-one API development, documentation, and testing platform designed for developers and QA teams. It combines API design, debugging, testing, and mocking in a single interface, making it a strong choice for teams that want a collaborative API lifecycle tool. It combines the features of tools like Postman and Swagger.
Features of Apidog
- Comprehensive protocol support – Supports Test REST, GraphQL, WebSocket, and gRPC APIs.
- Powerful request builder – Configure GET, POST, PUT, DELETE, PATCH requests with headers, parameters, and payloads.
- Schema & response validation – Validate status codes, headers, and JSON schema with assertions.
- Environment management – Manage dev, staging, and production environments with variables for tokens, URLs, and headers.
- Authentication handling – Supports OAuth 2.0, JWT, API keys, and Basic authentication.
ContextQA
ContextQA is a modern, AI-powered test automation platform designed to simplify testing across APIs, web, and mobile applications. It focuses on providing codeless automation, making it accessible to QA teams of all skill levels, while still offering flexibility for advanced testing.
Features of ContextQA
- Protocol support – Test REST and GraphQL APIs directly within the platform.
- Easy request building – Configure GET, POST, PUT, DELETE requests with headers, parameters, and request bodies.
- Response validation – Validate status codes, response payloads, headers, and schema rules with assertions.
- Authentication handling – Supports OAuth 2.0, API keys, and token-based authentication.
- Environment management – Create and switch between environments (dev, staging, production) with reusable variables.
vREST
vREST is a specialized API testing tool focused on functional and regression testing of REST APIs. It provides a structured approach for designing, automating, and managing test cases for API testing without requiring heavy scripting. It is especially useful for QA teams that want simplicity and consistency in API testing.
Features of vREST
- Request building – Configure standard HTTP methods like GET, POST, PUT, DELETE with headers, parameters, and payloads.
- Response validation – Validate status codes, headers, and response payloads with assertions.
- Authentication support – Works with Basic Auth, API keys, and token-based authentication.
- Environment & variable management – Create multiple environments and reuse variables across test cases.
- Automation-ready – Automated regression testing for APIs; tests can be included in CI/CD pipelines.
- Chained requests – Use responses from one request as input to another for end-to-end validation.
- Reporting & debugging – Provides structured test reports and logs for quick troubleshooting.
- Integrations – Works with Jenkins and other CI/CD tools for continuous testing workflows.
Insomnia
Insomnia is a lightweight yet powerful API client built for developers and testers who want to quickly design, debug, and test APIs. Known for its clean UI and speed, Insomnia supports multiple protocols and is especially popular among teams that work with modern API architectures like REST, GraphQL, and gRPC.
Key features of Insomnia include:
- Protocol support – REST, GraphQL, gRPC, and WebSocket APIs.
- Request building – Full support for GET, POST, PUT, DELETE, PATCH with headers, parameters, and payloads.
- Response validation – Inspect responses like status codes, headers, and payloads, with the ability to add assertions through plugins or scripting.
- Authentication handling – OAuth 2.0, JWT, Basic Auth, API keys, and Bearer tokens.
- Environment & variable management – Manage multiple environments with reusable variables, tokens, URLs, etc.
- Chained requests – Reuse outputs like tokens or IDs from one request into another.
- Collaboration – Share collections and environments with team members.
Hoppscotch
Hoppscotch is an open-source, lightweight API testing and collaboration platform designed as a faster alternative to tools like Postman. It runs in the browser, making it highly accessible, and focuses on simplicity, speed, and privacy-friendly testing. It′s especially popular among developers who want a minimal setup without cloud lock-in.
Features of Hoppscotch
- Request building – Create GET, POST, PUT, and DELETE requests with headers, query parameters, and payloads.
- Response validation – Inspect status codes, headers, and response bodies in real time.
- Authentication handling – Supports Basic Auth, Bearer tokens, API keys, and OAuth 2.0 flows.
- Environment & variables – Define environments and use variables for URLs, tokens, and parameters.
- Collaboration – Share API requests and collections with teams; cloud sync available but optional.
- Mocking & proxying – Built-in API mocking and proxy support for testing under different conditions.
- Automation – Limited; more suited for manual API exploration than large-scale automated test suites.
- Integrations – Import/export Postman collections, OpenAPI/Swagger support, GitHub sync.
Postman
Postman is one of the most widely used API testing tools, offering a robust suite for designing, debugging, documenting, and automating APIs. Its intuitive interface and vast ecosystem make it popular with developers and QA teams.
Features of Postman
- Protocol support - Supports REST, SOAP, and GraphQL protocols.
- Response validation - Rich request builder with headers, params, and payloads.
- Authorization - Assertions for status codes, headers, and schema validation.
- Authentication - Support types like OAuth 2.0, JWT, API keys for authentication.
- Multiple environment support - Provides different environments and variable management.
- Automation - Collection Runner for automation.
- Integration - Integrations with Git, CI/CD tools, and monitoring dashboards.
Soap UI
SoapUI is a well-established tool for testing SOAP and REST APIs, and it is popular in enterprise environments. It offers both a free open-source edition and a commercial version (ReadyAPI).
Features of SoapUI
- Protocol support - Strong SOAP and REST API testing with dedicated support for both protocols.
- Test functions - WSDL support for SOAP services, making it easy to import and test operations.
- Test support - Functional, security, and load testing built into a single platform.
- Advanced features - Data-driven testing with external files like CSV, Excel, or databases.
- Automation - Supports automation for advanced operations.
- CI/CD integration - CI/CD integrations for seamless pipeline execution.
Swagger
Swagger (now part of the OpenAPI ecosystem) is a framework for API design, documentation, and testing. Tools like Swagger UI and SwaggerHub allow teams to define APIs and test them quickly.
Features of Swagger
- API Definition - Define APIs using OpenAPI specifications.
- Documentation - Generate interactive API documentation.
- Test support - Swagger UI for manual testing.
- Code generation - Client and server code generation.
- Integration - Seamless integration with CI/CD pipelines for enhanced workflows.
Apache JMeter
JMeter is an open-source performance testing tool widely used for load and stress testing APIs. Though primarily for performance, it also supports functional API testing.
Features of Apache JMeter
- Load & Stress Testing - Simulate heavy traffic and concurrent users to measure API performance for REST and SOAP services.
- Parameterization & Data-Driven Testing - Run tests with dynamic inputs from CSV, databases, or variables to mimic real-world usage scenarios.
- Response Validation - Add assertions to verify response codes, data, and performance metrics.
- Reporting & Analysis - Generate detailed reports with graphs and charts for insights into latency, throughput, and errors.
- CI/CD Integration - Integrate with Jenkins, Git, or other CI/CD tools to run automated performance tests as part of pipelines.
REST Assured
REST Assured is a powerful Java-based library designed specifically for automating REST API testing. Unlike GUI-based tools, it is code-centric, making it ideal for developers and QA engineers who are comfortable with scripting. It integrates seamlessly with popular testing frameworks like JUnit and TestNG, enabling easy test management and reporting within existing test suites.
Features of REST Assured
- Fluent Java DSL - Provides a simple, readable Domain-Specific Language (DSL) in Java for writing expressive API tests.
- HTTP Method Support - Covers all major HTTP methods like GET, POST, PUT, and DELETE for RESTful API testing.
- Schema Validation - Enables JSON and XML schema validation to ensure response structure correctness.
- CI/CD Compatibility - Works smoothly within CI/CD pipelines, enabling automated API testing as part of the development workflow.
Parasoft SOAtest
Parasoft SOAtest is an enterprise-grade tool that supports functional, security, and compliance testing for APIs, microservices, and complex systems.
Features of Parasoft SOAtest
- Multi-Protocol Support - Supports REST, SOAP, GraphQL, and message queue (MQ) protocols for broad API coverage.
- Comprehensive Testing - Covers functional, load, and security testing in one platform.
- Service Virtualization - Simulates unavailable or incomplete APIs and services to enable early and parallel testing.
- Compliance Testing - Validates APIs against industry standards and regulations to ensure compliance (e.g., PCI, HIPAA).
- Enterprise Integrations - Integrates with CI/CD pipelines, test management tools, and enterprise ecosystems for large-scale adoption.
Runscope
Runscope, acquired by BlazeMeter, focuses on API monitoring and testing in production environments. It′s cloud-based and designed for continuous validation of live APIs.
Features of Runscope
- Cloud-Based Platform - Provides API testing and monitoring directly from the cloud without complex setup.
- Protocol Support - Supports both REST and SOAP APIs for versatile testing needs.
- Environment & Variables - Enables environment switching and variable management for reusable test configurations.
- Monitoring & Alerts - Offers detailed dashboards, performance metrics, and real-time alerts for API health monitoring.
- Integrations - Integrates seamlessly with CI/CD pipelines, Slack, and other collaboration tools for efficient workflows.
Taurus
Taurus is an open-source test automation framework for performance and functional testing. It provides a simplified YAML/JSON layer over tools like JMeter, Locust, and Selenium.
Features of Taurus
- Simplified Scripting - Allows test creation using easy-to-read YAML/JSON configurations, reducing scripting complexity.
- Multiple Backend Support - Works with popular load-testing tools like JMeter, Locust, Gatling, and others as execution engines.
- Performance & Load Testing - Enables scalable performance and load testing for APIs and services.
- CI/CD Integration - Fits smoothly into CI/CD pipelines to run automated performance tests during development cycles.
- Unified Reporting - Provides consolidated reporting with metrics and logs across different testing backends.
Factors To Consider While Choosing The Best
API Testing Tool
When selecting an API testing tool, teams should look beyond just feature checklists. Here are key factors to evaluate:
Protocol Support – Ensure the tool supports the types of APIs you use (REST, SOAP, GraphQL, gRPC, MQ, etc.).
Ease of Use – Codeless or low-code tools benefit non-technical users, while code-based frameworks may suit developer-heavy teams.
Automation & CI/CD Integration – Look for tools that seamlessly fit into your DevOps pipelines for continuous testing.
Scalability – The tool should handle growing project complexity, higher test volumes, and larger teams.
Environment & Data Management – Features like parameterization, test environments, and data-driven testing are essential for realistic test coverage.
Collaboration & Reporting – Built-in dashboards, real-time reporting, and integrations with project management or bug-tracking tools improve team productivity.
Cost & Licensing – Balance between open-source flexibility and enterprise-grade paid solutions based on budget and support needs.
Community & Support – A strong user community, active documentation, and vendor support can speed up adoption and troubleshooting.
Conclusion
By carefully considering factors like protocol support, ease of use, CI/CD compatibility, and reporting capabilities, you can select a tool that aligns with your workflow and helps deliver high-quality software at speed. Whether you need a lightweight open-source API testing framework or an enterprise-grade AI-powered platform, the best API testing tool in 2025 ensures faster releases, fewer defects, and more reliable digital experiences.
Frequently Asked Questions
What is API Testing Tool?
Importance of API Testing Tool
Is Testsigma the Best API Testing Tool?
Which automated API testing tools are considered top choices for 2025?
Are there any open source API testing Tools mentioned in the List?
