API testing has become an integral part of the modern software development process. In 2025, there are new solutions and updates that make this process more automated, faster and more accurate. Below is an overview of the most relevant and in-demand tools today.

Postman (updated in 2025)

What’s New: Postman remains the market leader due to its stability, support for collections, environments, and automation. Added in 2025:

• AI tests (based on Postbot machine learning models);
• Deep integration with GitHub Copilot and Bitbucket;
• Multiprotocol support (gRPC, WebSocket, GraphQL).

Pros:

• Comfortable UI;
• Automation support (CI/CD);
• Extensibility with plugins.

Minuses:

• Limited functionality in the free version.

Insomnia (v2025.1)

Developed by Kong, Insomnia continues to evolve as an alternative to Postman.

New 2025 features:

• Extended work with OpenAPI 3.1;
• Environment templates with variables imported from Kubernetes and Docker;
• AI-generated query generation based on natural language description.

Pros:

• Minimalistic interface;
• Swagger/OpenAPI support;
• Excellent integration with Kong Gateway.

Minuses:

• Smaller community compared to Postman.

Hoppscotch (formerly Postwoman)

Hoppscotch is a progressive open-source tool for rapid API testing right in the browser.

Features 2025:

• Full-fledged PWA (can be used as a desktop application);
• Integration with WebSockets, MQTT, SSE;
• Advanced CLI utility (hoppscotch-cli).

Pros:

• Lightweight, fast and free;
• Simple interface;
• Great for REST and GraphQL.

Minuses:

• Not suitable for complex automation scenarios.

REST Assured (Java library).

For automated API testing in the Java ecosystem, REST Assured is still relevant.

In 2025:

• Support for JUnit 5, TestNG 8, and Spring Boot 3.2;
• Improved handling of OAuth2 and JSON Schema Validation.

Pros:

• Flexibility and power;
• Integration with CI/CD Pipelines.

Minuses:

• Requires Java knowledge;
• Less convenient for manual testing.

Katalon Studio (v9.0).

Katalon offers all-in-one from UI to API testing. The 2025 version includes:

• Integration with OpenTelemetry and Prometheus to analyze API performance;
• Improved TestOps for test case management;
• Support for SOAP, REST, and GraphQL.

Pros:

• Versatility;
• Support for no-code/low-code.

Minuses:

• High system requirements;
• There may be problems with customization.

Paw (macOS)

A macOS exclusive tool that recently received a support update:

• gRPC;
• OpenAPI Codegen;
• Synchronization with SwaggerHub.

Pros:

• Beautiful interface;
• Flexible work with authorization.

Minuses:

• MacOS only;
• No Windows/Linux version.

Conclusion

In 2025, API testing tools are becoming increasingly intelligent, agile and integrated into modern DevOps and CI/CD processes. The main trends are support for various protocols (REST, GraphQL, gRPC), active implementation of artificial intelligence for test generation and analysis, and advanced automation.

The choice of the appropriate tool depends on the specific tasks of the team. For simple and visual manual testing, Postman or Insomnia are suitable. Developers working in the Java ecosystem should pay attention to REST Assured. If automation and visual interface are important, Katalon Studio is an excellent choice. And for those who prefer lightweight and fast open source solutions, Hoppscotch is ideal.

Effective API testing is not just a functionality check, but an important part of ensuring stability, security and quality of digital products. Using modern tools can significantly reduce development time and increase the reliability of services.