Quick Overview
- 1#1: Postman - Comprehensive API platform for designing, testing, documenting, and automating APIs with collaboration features.
- 2#2: Insomnia - Powerful open-source API client for designing, debugging, and testing REST and GraphQL APIs.
- 3#3: ReadyAPI - Enterprise-grade API testing tool supporting functional, performance, and security testing for REST and SOAP.
- 4#4: SoapUI - Open-source tool for functional testing of SOAP and REST web services with scripting support.
- 5#5: Apache JMeter - Open-source application testing tool focused on load and performance testing of APIs.
- 6#6: Hoppscotch - Lightweight open-source API client for sending HTTP requests and testing endpoints with real-time collaboration.
- 7#7: Bruno - Offline-first open-source API client that stores requests in plain files for easy version control.
- 8#8: Katalon Studio - All-in-one test automation platform with robust API testing capabilities using record-and-playback.
- 9#9: HTTPie - User-friendly command-line HTTP client for testing APIs with human-readable syntax.
- 10#10: Karate - Open-source framework for API test automation using BDD Gherkin syntax and built-in HTTP client.
We selected and ranked these tools based on features (including functionality, collaboration, and scalability), user experience, performance consistency, and value, ensuring the most impactful and versatile solutions are prioritized.
Comparison Table
This comparison table examines leading API testing tools, such as Postman, Insomnia, ReadyAPI, SoapUI, Apache JMeter, and others, to aid in selecting the most suitable solution for your testing requirements. It breaks down key features, strengths, and ideal use cases, empowering readers to make informed choices for efficient API validation and workflow optimization.
| # | Tool | Category | Overall | Features | Ease of Use | Value |
|---|---|---|---|---|---|---|
| 1 | Postman Comprehensive API platform for designing, testing, documenting, and automating APIs with collaboration features. | specialized | 9.7/10 | 9.9/10 | 9.2/10 | 9.5/10 |
| 2 | Insomnia Powerful open-source API client for designing, debugging, and testing REST and GraphQL APIs. | specialized | 9.2/10 | 9.5/10 | 9.3/10 | 9.7/10 |
| 3 | ReadyAPI Enterprise-grade API testing tool supporting functional, performance, and security testing for REST and SOAP. | enterprise | 9.1/10 | 9.6/10 | 8.7/10 | 8.4/10 |
| 4 | SoapUI Open-source tool for functional testing of SOAP and REST web services with scripting support. | specialized | 8.2/10 | 9.1/10 | 6.4/10 | 9.3/10 |
| 5 | Apache JMeter Open-source application testing tool focused on load and performance testing of APIs. | specialized | 8.7/10 | 9.2/10 | 7.0/10 | 10/10 |
| 6 | Hoppscotch Lightweight open-source API client for sending HTTP requests and testing endpoints with real-time collaboration. | other | 8.7/10 | 8.2/10 | 9.5/10 | 9.8/10 |
| 7 | Bruno Offline-first open-source API client that stores requests in plain files for easy version control. | specialized | 8.8/10 | 8.2/10 | 9.1/10 | 10/10 |
| 8 | Katalon Studio All-in-one test automation platform with robust API testing capabilities using record-and-playback. | enterprise | 8.2/10 | 8.4/10 | 8.1/10 | 9.0/10 |
| 9 | HTTPie User-friendly command-line HTTP client for testing APIs with human-readable syntax. | specialized | 8.7/10 | 8.2/10 | 9.6/10 | 9.5/10 |
| 10 | Karate Open-source framework for API test automation using BDD Gherkin syntax and built-in HTTP client. | specialized | 8.7/10 | 9.2/10 | 8.5/10 | 9.8/10 |
Comprehensive API platform for designing, testing, documenting, and automating APIs with collaboration features.
Powerful open-source API client for designing, debugging, and testing REST and GraphQL APIs.
Enterprise-grade API testing tool supporting functional, performance, and security testing for REST and SOAP.
Open-source tool for functional testing of SOAP and REST web services with scripting support.
Open-source application testing tool focused on load and performance testing of APIs.
Lightweight open-source API client for sending HTTP requests and testing endpoints with real-time collaboration.
Offline-first open-source API client that stores requests in plain files for easy version control.
All-in-one test automation platform with robust API testing capabilities using record-and-playback.
User-friendly command-line HTTP client for testing APIs with human-readable syntax.
Open-source framework for API test automation using BDD Gherkin syntax and built-in HTTP client.
Postman
specializedComprehensive API platform for designing, testing, documenting, and automating APIs with collaboration features.
Postman Workspaces for real-time team collaboration and the public API Network for discovering and forking pre-built API collections
Postman is a leading API development and testing platform that enables users to design, build, test, and document APIs with an intuitive graphical interface. It supports sending HTTP requests, automating tests via JavaScript scripting, managing collections and environments, and integrating with CI/CD pipelines through Newman CLI. Additionally, it offers team collaboration features, API monitoring, mocking, and a public API Network for discovering shared APIs.
Pros
- Comprehensive testing tools including automated test suites, assertions, and data-driven testing
- Seamless collaboration with workspaces, real-time editing, and version control
- Extensive integrations with tools like Git, Jenkins, and Newman for CI/CD automation
Cons
- Free plan limits (e.g., 25 collections, 1K API calls/month) restrict heavy usage
- Desktop app can be resource-intensive on lower-end machines
- Advanced features like API governance require higher-tier plans
Best For
API developers, QA engineers, and dev teams requiring collaborative, scalable API testing and automation.
Pricing
Free plan for individuals; paid tiers start at $12/user/month (Basic), $29/user/month (Professional), with Enterprise custom pricing.
Insomnia
specializedPowerful open-source API client for designing, debugging, and testing REST and GraphQL APIs.
Interactive GraphQL query builder with automatic schema introspection and documentation generation
Insomnia is a powerful open-source API client for designing, testing, and debugging REST, GraphQL, gRPC, and WebSocket APIs with a clean, intuitive interface. It supports environments, variables, request chaining, multiple authentication types, and a robust plugin ecosystem for extensibility. Acquired by Kong, it offers optional cloud sync and team collaboration while prioritizing offline-first performance.
Pros
- Open-source core with no cost for individual use and full offline functionality
- Excellent native support for GraphQL (including introspection and query builder) and gRPC
- Lightweight, fast, and intuitive UI with advanced features like plugins and environments
Cons
- Team collaboration and cloud sync require paid subscription
- Smaller plugin ecosystem and community compared to Postman
- Limited built-in API documentation and reporting capabilities
Best For
Developers and small teams seeking a free, high-performance API testing tool with strong GraphQL and gRPC support.
Pricing
Free open-source desktop app; Insomnia Cloud team plans start at $5/user/month for collaboration and sync.
ReadyAPI
enterpriseEnterprise-grade API testing tool supporting functional, performance, and security testing for REST and SOAP.
Integrated service virtualization for creating mock APIs without relying on live backends or third-party services
ReadyAPI by SmartBear is a comprehensive API testing platform supporting REST, SOAP, GraphQL, and JMS protocols for functional, load, security, and virtualization testing. It features a low-code graphical interface for test creation, advanced Groovy scripting, and seamless integration with CI/CD pipelines like Jenkins and Bamboo. The tool enables teams to validate APIs end-to-end, simulate environments via virtualization, and generate detailed compliance reports.
Pros
- All-in-one support for functional, performance, security testing, and virtualization
- Strong CI/CD integrations and detailed reporting capabilities
- Low-code drag-and-drop interface with powerful scripting options
Cons
- Higher pricing limits appeal for small teams or startups
- Learning curve for advanced scripting and customization
- Can be resource-heavy during large-scale load tests
Best For
Enterprise and mid-sized teams needing integrated API testing with virtualization and performance validation in complex environments.
Pricing
Subscription-based; starts at $699/user/year for ReadyAPI Test Pro, with add-ons for LoadUI Pro ($999/user/year) and virtualization.
SoapUI
specializedOpen-source tool for functional testing of SOAP and REST web services with scripting support.
Deep native support for SOAP WS-* standards and WS-Security testing
SoapUI is a popular open-source API testing tool designed for testing SOAP and REST web services, enabling users to create functional, load, security, and compliance tests. It supports test case development with reusable steps, assertions, data-driven testing, and service mocking. With Groovy scripting integration, it allows for complex automation scenarios in API validation workflows.
Pros
- Extensive support for SOAP, REST, and other protocols with functional, load, and security testing
- Powerful Groovy scripting for advanced customization and automation
- Free open-source version with robust core features
Cons
- Outdated and cluttered user interface
- Steep learning curve for beginners
- Performance issues with large projects or high loads
Best For
Experienced QA engineers and developers handling complex SOAP-heavy API testing environments who need scripting flexibility.
Pricing
Free open-source edition; ReadyAPI Pro subscription starts at $699/user/year for functional testing, with add-ons for performance and security.
Apache JMeter
specializedOpen-source application testing tool focused on load and performance testing of APIs.
Distributed testing mode for simulating massive concurrent loads across multiple remote machines
Apache JMeter is an open-source Java-based tool primarily designed for load and performance testing of applications, servers, and APIs. It supports comprehensive API testing through HTTP/HTTPS samplers, REST, SOAP, JDBC, and more, allowing users to create test plans with assertions, variables, and scripting for functional and scalability validation. While versatile, it shines in simulating high loads and measuring response times across diverse protocols.
Pros
- Completely free and open-source with no licensing costs
- Broad protocol support including REST, SOAP, WebSocket, JMS, and databases
- Highly extensible via plugins, custom samplers, and scripting (BeanShell, Groovy)
Cons
- Steep learning curve due to XML-based test plans and complex GUI
- Resource-heavy, consuming significant CPU/memory during large-scale tests
- Basic functional testing requires manual setup of assertions and lacks intuitive UI like modern tools
Best For
Development and QA teams needing robust, customizable performance and load testing for APIs without budget constraints.
Pricing
Free (open-source under Apache License 2.0).
Hoppscotch
otherLightweight open-source API client for sending HTTP requests and testing endpoints with real-time collaboration.
Unified interface supporting multiple protocols like GraphQL, WebSockets, and SSE alongside traditional REST in a single, blazing-fast client
Hoppscotch is an open-source API testing tool that provides a lightweight, intuitive alternative to Postman for sending HTTP requests, GraphQL queries, WebSocket connections, and more. It features a clean web-based interface with support for collections, environments, variables, and various authentication methods. Available as a progressive web app, desktop client, CLI, and self-hostable backend, it emphasizes speed and simplicity for API development and testing workflows.
Pros
- Completely free and open-source with no usage limits for core features
- Intuitive, modern UI that's faster and less bloated than competitors
- Broad protocol support including REST, GraphQL, WebSockets, SSE, and Socket.IO
Cons
- Lacks advanced enterprise features like API mocking, automated testing, or monitoring
- Team collaboration and advanced sharing require paid Pro plans
- Fewer third-party integrations compared to tools like Postman
Best For
Solo developers, small teams, or hobbyists seeking a free, lightweight API client for quick testing and prototyping without unnecessary complexity.
Pricing
Free for individuals with unlimited use; Pro/Teams plans start at $5/user/month for collaboration and advanced features.
Bruno
specializedOffline-first open-source API client that stores requests in plain files for easy version control.
Plain text (.bru) file format for requests and collections, enabling effortless Git version control without proprietary lock-in.
Bruno is a lightweight, open-source API client for testing, debugging, and documenting APIs, available as a desktop app for Windows, macOS, and Linux. It allows users to create collections of HTTP requests, supports GraphQL, authentication methods, variables, scripting, and tests in JavaScript. Unlike cloud-based tools, Bruno stores everything as plain text files in a folder structure, enabling native Git version control and full offline functionality.
Pros
- Fully free and open-source with no usage limits
- Plain text file storage for seamless Git integration and collaboration
- Fast, lightweight performance with excellent offline support
Cons
- No built-in cloud sync or team collaboration features
- Limited advanced enterprise tools like API mocking or monitoring
- Younger tool with occasional UI polish and plugin ecosystem gaps
Best For
Solo developers or small Git-savvy teams seeking a simple, local-first API testing tool.
Pricing
Completely free (open-source, no paid tiers).
Katalon Studio
enterpriseAll-in-one test automation platform with robust API testing capabilities using record-and-playback.
Low-code API recorder that automatically generates executable tests from live traffic captures
Katalon Studio is a versatile test automation platform that provides robust API testing capabilities for REST, SOAP, and GraphQL endpoints alongside web, mobile, and desktop testing. It features a low-code recorder for capturing and generating API tests, custom scripting in Groovy or JavaScript, and support for data-driven testing with built-in assertions and validation. The tool integrates with CI/CD pipelines like Jenkins and offers comprehensive reporting, making it a solid choice for teams seeking an all-in-one solution.
Pros
- Powerful free Community edition with full API testing features
- Intuitive record-and-playback for quick API test creation
- Strong CI/CD integrations and cross-platform test management
Cons
- Steeper learning curve for advanced Groovy scripting
- Occasional performance lags with very large test suites
- Limited native API mocking compared to specialized tools
Best For
QA teams and developers needing a cost-effective, all-in-one automation tool with reliable API testing in agile environments.
Pricing
Free Community edition; Team plan starts at $25/user/month; Enterprise custom pricing.
HTTPie
specializedUser-friendly command-line HTTP client for testing APIs with human-readable syntax.
Elegant, natural-language-like syntax for crafting complex HTTP requests effortlessly
HTTPie is a user-friendly command-line HTTP client designed as a modern alternative to curl, making it exceptionally easy to test and interact with APIs directly from the terminal. It supports features like intuitive syntax for requests, automatic JSON pretty-printing with colorized output, sessions for persistent auth, plugins for extensibility, and advanced capabilities such as HTTP/2, streaming, and file uploads. A newer Desktop GUI version extends its accessibility beyond CLI users, positioning it as a versatile tool for API development and testing workflows.
Pros
- Intuitive, human-readable syntax far superior to curl
- Beautiful colorized output and automatic JSON handling
- Lightweight, fast, and highly scriptable for automation
Cons
- Primarily CLI-focused with limited GUI capabilities in the free version
- Lacks advanced testing features like assertions, collections, or visual workflows
- No built-in team collaboration or reporting tools
Best For
Developers and DevOps professionals who prefer terminal-based API testing and scripting.
Pricing
Free open-source CLI; Desktop app with generous free tier and Pro plans starting at $9/user/month for teams.
Karate
specializedOpen-source framework for API test automation using BDD Gherkin syntax and built-in HTTP client.
Plain-English DSL for writing API tests that doubles as living documentation
Karate is an open-source API testing framework that uses a simple, readable DSL inspired by Cucumber Gherkin, enabling automated tests for REST, GraphQL, SOAP, and more without boilerplate code. It supports end-to-end testing including UI automation via Selenium integration, performance testing, and contract validation. Designed for developers and testers, it runs on JVM, requires no external dependencies, and provides built-in reporting and parallel execution.
Pros
- Human-readable, BDD-style test scripts that are easy to maintain
- Comprehensive API support including auth, mocks, and performance testing
- Zero dependencies and cross-platform execution
Cons
- Limited native IDE integration and debugging tools
- JVM requirement may deter non-Java users
- Reporting lacks advanced customization compared to enterprise tools
Best For
Development teams seeking a lightweight, script-based API testing solution for agile environments without heavy setup.
Pricing
Core framework is free and open-source; paid options include Karate Cloud (starts at $99/month) and enterprise support.
Conclusion
The top API testing tools reviewed showcase Postman as the unrivaled choice, with its comprehensive integration of design, testing, documentation, and collaboration. Insomnia and ReadyAPI follow, offering distinct strengths—Insomnia's open-source flexibility and ReadyAPI's enterprise-focused performance and security testing. Whether for small projects or large-scale needs, these tools highlight robust solutions, but Postman leads as a versatile, end-to-end platform.
Explore Postman to leverage its all-in-one capabilities and simplify your API testing journey, or dive into Insomnia or ReadyAPI based on your specific requirements.
Tools Reviewed
All tools were independently evaluated for this comparison