January 8, 2024
12 Best API Testing Tools To Ensure Reliability But Not Issues In 2024
Long Story Short
Selecting the right API testing tool is A critical choice that directly affects the effectiveness and reliability of software development processes. There are many various types of API testing tools available. Each one has special advantages suited to a certain set of requirements.
The best API testing tool ultimately comes down to the unique requirements, tastes, and demands of a development team. Whether prioritizing simplicity, performance, or comprehensive API management, each tool in this diverse landscape has strengths. The optimal choice hinges on aligning these strengths with the unique demands of the development environment.
Do you need assistance choosing the right tool set? We are here to help you. Reach out to us, and we will choose the best API testing tools for your project.
This challenge is choosing the right automated API testing tools. The modern, ever-changing IT market offers a myriad of them. It helps companies streamline the testing lifecycle and enhance test coverage. However, this turns the choosing process into a real challenge.
Based on our experience, we gathered our TOP 12 API automation testing tools.
API Testing Challenge That Requires Special Attention
Postman simplifies API testing and quickly integrates it into the CI/CD pipeline, allowing for accelerated development, testing, and monitoring. The Postman API development environment includes collections, built-in tools, and workspaces. You can execute requests, debug, test, create, and document simulation scenarios, as well as monitor APIs.
Postman is useful for monitoring, debugging, testing, etc.
Versatility
Postman's community offers extensive knowledge and documentation.
Community and documentation
Postman integrates well with other development tools and services. It makes it a valuable part of the development workflow.
Integration
Postman receives regular updates and improvements, ensuring relevance to evolving technologies.
Regular updates
The free basic pricing plan offers all the required capabilities.
Free basic plan
Strengths
Postman can be resource-intensive. This affects performance on less powerful machines.
Resource intensive
Some developers prefer command-line tools. Postman's reliance on a graphical interface may not cater to everyone's preferences.
Dependency on a GUI
The quantity of requests, monitoring, and other sophisticated capabilities are restricted in the free edition.
Limited free tier
Weaknesses
Swagger, now known as the OpenAPI Specification, is not an API testing tool per se; instead, it is a framework for describing RESTful APIs. It can also automatically generate client SDKs and documentation.
OpenAPI Specification is widely adopted and supported, promoting interoperability between tools and frameworks.
Open standard
Many enterprises use and support OpenAPI. It's like a collection of their knowledge from building many APIs over the years.
Huge user base
Generating client libraries in various languages reduces the effort developers need to use the API.
Client libraries
Strengths
For beginners, understanding and using OpenAPI efficiently may be challenging.
Complexity
Using OpenAPI may be seen as overkill for small, simple APIs, adding unnecessary complexity.
Overhead
Weaknesses
SoapUI is a cross-platform, open-source API testing tool. It allows testers to perform automated regression, functional, load, security, and compliance testing. It supports API testing because SoapUI is compatible with standard protocols such as SOAP/WSDL, JMS, REST, AMF, JDBC, etc.
SoapUI supports both SOAP and REST. It is suitable for testing a wide variety of web services.
Support for multiple protocols
Both beginners and experienced testers can create and execute tests efficiently.
Intuitive interface
SoapUI supports data-driven testing. This means testers can cover various scenarios using different input data.
Flexible data handling
You can extend SoapUI through plugins and custom scripts. It helps you tailor the tool to your specific needs.
Extensions and plugins
Strengths
SoapUI is easy to start with. However, some of its features might have a steeper learning curve.
Complex features
Running extensive test suites or load tests can be resource-intensive.
Resource usage
The Pro version offers advanced capabilities but has an additional fee.
Pro version features
Weaknesses
Insomnia is a simple tool for testing and debugging APIs. It enables you to send requests, view responses, and analyze errors. Insomnia supports a broad range of capabilities for interacting with various APIs: a set of HTTPs methods, calls to gRPC APIs, as well as custom methods with their parameters.
Insomnia is available on multiple platforms, including Windows, macOS, and Linux.
Multiple platforms
Insomnia includes a plugin system. It helps modify processes, add new features, or integrate additional tools.
Extensibility
Users can easily create HTTP requests using various methods (GET, POST, etc.). Additionally, they can customize headers, parameters, and body content.
Flexible request building
Insomnia allows users to generate code snippets in various programming languages based on the requests they create, facilitating integration with code projects.
Code generation
Strengths
While Insomnia excels in testing RESTful APIs, it might not be the best choice for projects heavily reliant on other protocols like SOAP.
Focused on REST
Some functionalities required for extensive corporate API testing may not be available in Insomnia.
Enterprise-level features
Insomnia primarily focuses on creating and testing individual requests and responses. It may lack some of the advanced testing features found in more comprehensive testing tools.
Focused on request/response
Weaknesses
Katalon Studio facilitates the automation of web, mobile, and desktop application testing as well as API testing. It is highly functional and operates on Windows, Linux, and macOS.
The user-friendly design of Katalon Studio is beneficial to testers of all experience levels.
Low learning curve
Katalon Studio includes a built-in object repository for managing test objects enhancing test maintenance and reusability.
Object repository
Katalon Studio supports BDD by integrating tools like Cucumber and Gherkin, enabling collaboration between developers, testers, and other stakeholders.
Behavior-driven development (BDD)
Katalon Studio offers features for organizing and managing test cases. It facilitates test suite scaling and maintenance for teams.
Test case management
Katalon Studio can integrate with popular version control systems like Git, facilitating collaboration and versioning of test scripts.
Version control
Katalon Studio provides built-in reporting features, offering insights into test execution results.
Test reporting
Strengths
Katalon Studio supports scripting in Groovy. However, some users prefer more common programming languages.
Scripting language
Smaller teams or individual testers on a tight budget might find Katalon Studio's pricing plan unsuitable.
Pricing structure
Katalon Studio is suitable for many testing scenarios that are out of the box. More advanced customization options might be limited compared to tools with a more open architecture.
Advanced customization
Weaknesses
Charles Proxy is a web debugging proxy application commonly used by developers, testers, and network administrators. It allows users to monitor, inspect, and manipulate network traffic between a computer or mobile device and the internet. Charles Proxy is widely used for various purposes, including monitoring and testing API requests and responses.
Charles Proxy offers a comprehensive view of HTTP and HTTPS traffic. This facilitates the understanding and debugging of client-server interactions.
Traffic monitoring and inspection
Developers can set breakpoints to intercept and inspect requests and responses. This simplifies debugging and analyzes how a server and an application communicate.
Breakpoints
Charles Proxy supports SSL proxying, allowing users to inspect encrypted HTTPS traffic by acting as a man-in-the-middle. This is beneficial for debugging secure connections.
SSL proxying
It allows users to simulate different network conditions by throttling the bandwidth. This helps assess application performance on various network speeds.
Bandwidth throttling
Strengths
Charles Proxy may be overwhelming for beginners, especially those new to network debugging.
Complexity for beginners
The full version of Charles Proxy is paid. Depending on the user's needs, the cost may be a consideration.
Cost
Weaknesses
RestSharp is a popular open-source library. It simplifies making HTTP requests and handling responses and facilitates interaction with RESTful APIs in .NET projects.
RestSharp is designed with RESTful principles. It supports standard HTTP methods like GET, POST, PUT, DELETE, etc.
Support for RESTful principles
RestSharp supports various authentication mechanisms. This makes it versatile for interacting with APIs that require authentication.
Authentication support
Support for serializing and deserializing XML and JSON data is included in RestSharp. This simplifies interacting with RESTful APIs and processing complicated data structures.
Serialization and deserialization
RestSharp allows developers to make asynchronous HTTP requests, improving the performance of applications that handle multiple requests simultaneously.
Asynchronous support
Strengths
RestSharp's documentation cannot be thorough enough. In specific use cases, users must rely on community resources.
Limited built-in documentation
RestSharp doesn't provide a standalone user interface or test runner. You need to integrate it into a .NET application.
Not a standalone tool
The open-source community works to create and maintain RestSharp. You have to consider that some security upgrades and new features won't be supported immediately.
Updates and maintenance
Weaknesses
JMeter is a free, open-source tool for load, functional, unit testing, etc. It is primarily used for web applications, but it can also be used for basic performance monitoring.
Apache JMeter is used for performance testing and simulating multiple users. It is required to test the performance and scalability.
Performance testing
JMeter supports distributed testing, allowing users to scale their tests across multiple machines to simulate a larger number of virtual users and increase testing capacity.
Distributed testing
JMeter is compatible with many protocols and servers. These are LDAP, FTP, HTTP, HTTPS, SOAP, etc.
Rich set of protocols
JMeter allows users to create custom plugins and functions. It helps meet specific testing requirements.
Extensibility
Strengths
JMeter's reporting capabilities may not be enough over some commercial performance testing tools.
Limited reporting
Individual testers often use JMeter. It’s because its collaboration features may not be enough as in some other testing tools for team environments.
Limited collaboration features
Weaknesses
Paw is a powerful API testing and development tool designed for macOS. It provides a user-friendly interface for developing, testing, and debugging APIs. This tool allows businesses to check APIs, make requests, create client code, save API details, etc. Paw makes teamwork easier by letting users sync their tests.
Paw supports dynamic values and environments. Users can use it to design requests adaptable to various scenarios. This is useful for handling authentication tokens, variables, and dynamic data.
Dynamic values and environments
Drawing from predefined API requests, Paw can produce code snippets in multiple programming languages. This feature accelerates the development process.
Code generation
Paw supports environment variables and configurations. You can use different parameters for testing in various environments.
Environment variables and configurations
Paw supports importing and exporting API requests and configurations. It facilitates collaboration and sharing of test cases among team members.
Import and export
Strengths
Paw is available only for macOS, which limits its usability for users on other operating systems.
macOS exclusive
Paw offers a free trial. But you must purchase a license to use all of its features.
Paid software
Weaknesses
Karate combines API testing, test automation, and performance testing. It streamlines API testing by employing a straightforward syntax based on the Gherkin language.
Karate uses a BDD syntax. This makes it accessible to technical and non-technical team members.
BDD syntax
Karate supports data-driven testing. It simplifies changing and parameterizing test scenarios depending on various data types.
Data-driven testing
While Karate itself is primarily based on the Java Virtual Machine (JVM), it allows the inclusion of JavaScript for scripting purposes, providing flexibility for users with JavaScript expertise.
JavaScript integration
Karate minimizes the amount of boilerplate code needed for API testing. It simplifies testing for non-programmers.
No coding required
Karate can handle API and performance testing within the same framework. It reduces the need for separate tools for different testing phases.
2-in-1
Karate generates detailed HTML reports that include information on test results, scenarios, and timelines, aiding in the analysis of test execution results.
Detailed test reports
Strengths
Karate is pretty popular but still doesn’t have an extensive community or ecosystem. It could result in fewer resources and third-party integrations.
Limited ecosystem and community support
Compared to general-purpose programming languages, Karate might be less extensible for implementing custom functionality or integrations beyond its built-in capabilities.
Less extensible
Karate is built on the JVM. Utilizing many platforms or programming languages could be a limitation.
Java dependency
Weaknesses
REST-Assured is a Java-based domain-specific language that lets you write readable and powerful tests for RESTful APIs (not for SOAP APIs). As a Java library, it easily integrates with Junit, TestNG, or other Java frameworks and quickly fits into CI/CD processes. The code is human-readable as it supports the Given-when-then notation, similar to if-else statements.
REST-Assured uses a declarative syntax. It helps write tests in a natural and readable way.
Declarative syntax
REST-Assured is a Java library that seamlessly integrates with Java-based projects.
Integration with Java
REST-Assured supports a BDD approach to test writing, allowing users to describe test scenarios in a natural language format. This is achieved through the use of Given-When-Then syntax.
Support of the BDD approach
Setting up REST Assured for API testing is relatively straightforward and requires minimal configuration. This simplicity can be beneficial for getting started quickly.
Easy to Set Up
REST Assured supports various authentication mechanisms. This is crucial for testing APIs that require secure access.
Authentication support
REST-Assured is extensible. You can implement custom logic or integrate it with other libraries.
Extensibility
Strengths
As a Java library, REST-Assured is suitable for Java projects. When working with multiple programming languages, alternative tools could be needed.
Java dependency
REST-Assured is a full-featured Java library. It could be overkill for small projects with basic testing requirements. Simpler tools or frameworks might be more suitable.
Overkill for small projects
Weaknesses
Apigee is a tool for managing API gateways facilitating data exchange between cloud applications and services. It acts as a proxy, concealing the backend services' APIs. Apigee consists of two main components. Firstly, Apigee services enable API proxy server creation, deployment, and management. Secondly, the Apigee runtime environment processes and handles all API traffic. AI-based monitoring of APIs allows the quick identification of any issues with just a few clicks.
Apigee covers the entire API lifecycle. This end-to-end approach allows organizations to manage APIs efficiently.
Full API lifecycle management
Apigee includes robust analytics and monitoring capabilities. It also provides data on API performance, usage, and any problems.
API analytics and monitoring
Apigee is designed to process large-scale API deployments. This makes it suitable for enterprises with complex API requirements. It can scale horizontally to accommodate increasing API traffic.
Scalability
Apigee supports deployment in various cloud environments, providing flexibility for organizations that operate in multi-cloud or hybrid cloud architectures.
Multi-cloud deployment
Apigee includes many security features. It ensures that APIs are secure and compliant with industry standards.
Security features
Strengths
For simple projects or small-scale API implementations, Apigee's feature set could be excessive. Organizations with less complex requirements may find simpler tools more suitable.
Complexity for simple projects
Users opting for Apigee as an API testing tool are bound to the Apigee platform.
Dependency on the Apigee platform
The pricing structure is often inappropriate for small or budget-constrained projects.
Cost
Apigee's testing capabilities are more integrated with its API management features. It might be a limitation for offline testing.
Limited offline testing
Weaknesses
The reality turns out to be harsh. Software development requires seamless communication between components. So, API testing unfolds with multiple challenges.
Where can you step on a rake?
Sounds Сool, But How Does It Work in Practice?
Setting up a proper test environment that mimics the production one is like assembling a house of cards. Especially if the API relies on third-party services or external dependencies. You are stacking each card carefully, hoping that the slightest breeze (or API hiccup) doesn't make your carefully crafted structure tumble.
Test environment setup
Handling different data types is much like attempting to juggle multiple fruits simultaneously. Just as juggling requires a keen sense of coordination, handling data variety demands a thorough approach to ensure nothing gets dropped or mixed up.
Data management
Dependency on external systems
APIs may depend on external services. In this case, testing these dependencies can be challenging. The reliability of API tests may be impacted by the following:
Modifications made to third-party APIs
Issues with the network
Service interruptions
Security concerns
Challenges in this area include the following:
Handling authentication tokens
Securing sensitive data in transit
Protecting against common security threats like SQL injection or cross-site scripting
It looks like a digital James Bond mission, doesn’t it?
APIs must pass performance tests in a variety of scenarios. You can’t ensure scalability without identifying and resolving bottlenecks in API performance.
Performance testing
In case of invalid requests, APIs must return error responses. But clear reporting issues can be difficult.
Error handling
Despite the crucial role automation plays in enhancing API testing efficiency, the creation and upkeep of automated scripts pose formidable challenges. The fluid nature of APIs, dynamic data, and evolving requirements introduces complexities that demand adept handling to ensure the sustained effectiveness of automated testing processes.
Automation challenges
Both manual and automated approaches are available for API testing. But why do businesses prefer automated testing? It’s because of its several advantages over manual testing.
To Automate, or Not to Automate, That is the Question
Speed and efficiency: Automation allows for fast test scenario execution, significantly reducing the testing lifecycle. This rapid feedback loop helps identify and address potential issues promptly.
1.
CI/CD pipelines: To streamline and improve the efficiency of the development workflow, integrate automated testing into these pipelines. This integration ensures that each code change undergoes rigorous testing automatically. It promotes a more reliable and stable codebase.
2.
Better coverage: Automated tests cover various scenarios, edge cases, and input variations. It helps identify potential issues overlooked in manual testing.
3.
Software validation: API testing provides complete software validation by extending its capabilities to acceptance and load testing. In acceptance testing, automated scripts can simulate real user interactions, validating that the API functions as expected in various scenarios. Load testing helps evaluate the system’s performance under various stress conditions.
4.
Handling complex and repetitive tasks: APIs often involve intricate interactions, and automated tests consistently replicate these interactions. This lessens the possibility of human error.
5.
Every day, we use applications on our phones, work on the internet through a browser, make purchases using bank cards, and perform numerous other actions with electronic gadgets that communicate with each other through APIs.
Fun fact: APIs make up over 83% of Internet traffic. They assist in creating omnichannel experiences, expediting innovation, enhancing business efficiency, and generating new revenue streams.
Moreover, public API can help our customers expand their market reach. The client offers a public API integrating with CRM platforms and third-party services that attract a broader customer base. The enhanced capabilities and seamless integrations positioned the client as a leader in the telecommunications industry. This, in turn, led to increased adoption and market share.
You must give a high degree of consistency when utilizing APIs. It is required to make the development process predictable. This method helps integrate software with already-existing programs without its modification. Seeking such a level of quality involves the use of API testing processes.
Various parts of applications are generally not tightly connected. At the same time, APIs reside in the ever-changing business layer. By utilizing API testing tools, any alterations in the request/response format or within the API itself can be identified in the early stages of testing. This streamlines the integration and regression testing phases, leading to a reduction in the software testing lifecycle.
Table of contents
Table of contents
Share on Social Media
Share
Let’s Discuss!
We are ready to assist you in your success!
You may also like
Outbound Calls
All you want to know about outbound call automation and its business benefits.
Speech Analytics
From pitfalls to benefits and practical insights — dive into the simplicity and impact of speech recognition technologies.
