JMeter vs Postman | Top 10 Key Differences

Functional testing helps to validate the functionality of web applications. Non-functional requirement testing (NFR Testing) helps to ensure the web application runs healthy under different circumstances. Both functional and non-functional testing are important in web applications. Functional testing can be done at different levels. Functionality testing at the user interface level is called end-to-end testing. Where we test the end-to-end flow and end-to-end components of web applications. Functionality testing can also be done at the application programming interface (API) level often we refer as API Testing. API testing is more stable and less flaky. Compared to user interface testing, API testing is much faster. Postman is a popular API testing tool and JMeter is popular performance testing however it can also be used for API testing. Let’s compare JMeter vs Postman to understand in detail.

Overview of Postman and JMeter

Postman and JMeter both can be used for API testing, both provide a rich user interface. Postman is more user-friendly. On the other hand, JMeter can help in Performance testing and chaos testing as well. Let’s look into them one by one.

What is JMeter?

JMeter is an open-source Performance and API testing tool. JMeter comes with an Apache 2.0 license hence no cost involved to use. JMeter has a visual editor, that provides the functionality to drag and drop to build the JMeter scripts. Additionally, JMeter also provides scripting functionality, allowing users to execute the Groovy and Javascript codes to meet their requirements. JMeter tests can be executed using the UI and command line tool (CLI). If you are using the JMeter for performance testing, as the number of users increases the UI may become laggy, hence it is recommended to use the CLI executor for performance tests.

JMeter is known for its extensibility, many open-source plugins are available for building the scripts, reporting, reading the files, parallel execution, etc. One can easily hook plugins to their framework and extend the required functionality. Additionally, many cloud vendors like Blazemeter also support JMeter which eliminates the infrastructure setup and maintenance.

What is Postman?

Postman is an API testing tool, it provides both a free version and a priced version with additional features. Postman is not an open-source tool. Using Postman one can test their APIs manual or automation. Postman tests can be executed using the user interface or using the command line tool newman. Interestingly, the whole collection of your API tests can be exported as a .json file and can be imported by others. 

Postman’s priced version has more advanced features like collaboration, advanced features like mocking, unlimited request and response, etc. Postman is not meant for performance testing, though you can execute the API tests in a loop it may not be able to mimic real user scenarios. Furthermore, Postman can be used for data-driven testing. Another interesting feature of Postman is it can be easily integrated with CI/CD and with the plugin support you can even generate a rich HTML report.

JMeter vs Postman – Key Differences

Postman is a good tool for your basic API testing. JMeter is more advanced and provides more features compared to Postman. Let’s understand the key differences between JMeter vs Postman.

Functionality and Purpose

Postman is primarily used for API testing. It supports both manual and automation testing of APIs. It is easy for beginners as the Postman interface is self understandable, you can just enter the API URL and add the required headers. Once you make the request, the response will be shown automatically in the response tab along with response headers. JSON response is pretty formatted hence there is good readability.

JMeter is primarily used for load and performance testing. JMeter can also be used for API testing. If you require to test only APIs then you might feel JMeter is complicated. As a performance testing tool, JMeter is widely popular and it can simulate thousands of real-time users and provide the metrics for you but as an API testing tool, JMeter may be difficult to use.

User Base

Postman is mostly used by the developers, test engineers, manual QA and automation QAs during API development, debugging, and testing the APIs

JMeter is used by performance engineers, to evaluate the system’s performance under different conditions.

Interface and Operation

Postman interface is more intuitive and easy to use. It comes with a rich visual editor where you can enter all the required details to test the API. Postman also provides console features to debug the APIs. The mocking feature helps to mock your dependent API data and test only the required APIs. Postman provides a command line interface called Newman. It is a nodeJS tool, which helps to execute the test in CI/CD.

JMeter has lots of features, it provides all different features support via user interface. Users might feel JMeter laggy if they are using a lower configuration system. However, when you talk about JMeter features and drag-and-drop support for those features, it feels rich and easy. You can use the JMeter UI for script development and execution, you can use the JMeter CLI.

Test Types

Postman is mainly used for API testing and integration testing. It may not fit well for performance testing. JMeter can be used for Performance testing and load testing. Though you can use the JMeter for API testing you may feel more complicated compared to Postman. 

Supported Protocols

Postman supports HTTP, HTTPS, and WebSocket protocols. JMeter supports HTTP, HTTPS, Websocket, JMS, FTP, SOAP, etc.

Primary Use Case

Postman’s primary use case is API testing which may include validating the API contracts, schema, JSON, Status, headers, etc.

JMeters primary use case is load and performance testing which may include capturing the performance metrics such as latency, response time, throughput, error rate etc.

User Interface

Postman has a rich and intuitive UI. The learning curve is less in Postman. JMeter UI is rich but there may be a good amount of learning required to use it. JMeter supports drag-and-drop features to build the test scripts.

Testing Scope

Postman is a great tool for API testing, you can build data-driven API tests and execute them on multiple iterations. You can even target the environments using the environment configurations. 

JMeter is a popular tool for Performance testing, it helps to build the tests and you can simulate the load on a web server. JMeter provides many performance metrics that help to identify the performance bottlenecks of your web application.

Supported Scripting Languages

Postman supports Javascript language for automation and API testing. These automated API tests can be integrated into popular CI/CD tools.

JMeter supports Groovy and Javascript languages. However, only advanced usage may require scripting in JMeter as most of the functionality can be achieved using the drag-and-drop feature.

Team Collaboration

Postman has a feature called Workspace, which helps to collaborate with team members in API testing and analysis. Postman collections can be exported to a .json file and others can import them hence it is easy to collaborate.

JMeter doesn’t have any collaboration feature out of the box, the only way to collaborate is by transferring the .jmx files.

Execution Modes

Postman supports both GUI and CLI execution modes. CLI mode is called Newman. One needs to export the Postman collection as a .json file and specify the path while running the tests via CLI. 

JMeter also has both UI and CLI execution modes. If you are creating hundreds of user loads then CLI mode is most preferred over GUI mode. 

Reporting Capabilities

Postman provides a rich validation report in HTML format. Optionally you can also choose JUnit reporting structure in Postman.

JMeter provides different types of reports such as HTML, JUnit, CSV, table format, etc. JMeter also provides an easy way to customize your reports.

Extensibility and Plugins

Postman provides limited integration and plugins, though it can serve all of your basic needs of API testing. But if you have specific customization requirements then it may be difficult using the Postman.

JMeter is an open source tool hence there are a lot of community-driven plugins available for free. It is easy to extend and customize the JMeter for your specific requirements.

Pros and Cons of Apache JMeter

Pros of JMeter

• Open source
• Platform-independent
• Supports different testing techniques
• Drag and drop support
• Highly extensible:

Cons of JMeter

• Not scalable GUI
• Lack of real-time monitoring
• Difficult to co-relate for recorded scripts
• high learning curve

Pros and Cons of Postman

Pros of Postman

• The free version helps to cover all basic API testing requirements
• Intuitive UI
• Supports API automation
• Supports collaboration feature
• Supports data-driven testing
• Easy-to-debug API tests
• Good community support

Cons of Postman

• A free tool has some limitations like maximum requests per day
• Consumes a lot of system resources
• Doesn’t support performance testing

When to Convert Postman Tests to JMeter Tests

Postman may only fulfill some of your testing requirements, Postman is built for specific purposes and the features of Postman are limited by design. You might have to think about converting Postman tests into JMeter tests in below scenarios

• When you want to capture end-to-end performance metrics
• If you want to mimic the user loads on your system
• If you have a requirement to find the bottlenecks of your API endpoints
• If you are looking for multithreaded execution.

How to Convert Postman API Tests to JMeter Tests

It’s easy to convert your Postman API scripts into JMeter scripts, as JMeter supports recording features. By following simple steps you can convert your tests into JMeter tests.

Step 1 – Prepare JMeter for Recording

Use the JMeter HTTPS script recorder to record the script. To do that, first start with adding the  HTTP(S) Test Script Recorder to your project.

• Go to the JMeter main menu choose File -> Templates -> Recording and click on “Create”
• Choose the HTTP(S) Test Script Recorder and click on start
• Enter the API hostname

Step 2 – Prepare Postman for Recording 

• JMeter generates a self-signed certificate when you launch JMeter’s HTTP(S) Test Script Recorder. A certificate with the name ApacheJMeterTemporaryRootCA.crt will be generated under the bin folder where you installed JMeter
• Navigate to Postman Settings > Certificates and toggle on CA certificates. Import the JMeter Certificate ApacheJMeterTemporaryRootCA.crt.

• Add a custom proxy configuration in your Postman by navigating to Postman’s Settings > Proxy > Proxy configurations for sending requests option
• Choose the Proxy Type HTTPS and HTTP  and use the localhost as a proxy server. Use 8888 as a proxy port

Step 3 – Record Your Tests

After completion of Step 3 Postman and JMeters interconnected. When you send the request from the Postman, JMeter will automatically capture those requests and convert them into JMeter scripts. If there are any headers then it will be added to the HTTP Header Manager.

Automatizing a Postman test with JMeter

Postman tests can be added to CI/CD pipelines but Postman cannot provide you the performance metrics. JMeter can support both API testing and performance testing. That means when you run your API tests you can also get performance insights into that particular endpoint.

Once you convert your Postman tests into JMeter tests using the above approach, you can easily integrate them into CI/CD pipelines or any other JMeter-supported automation framework to capture the API testing results, and performance metrics. You can also add assertions to performance metrics using the JMeter.

Alternatives to JMeter and Postman

Postman is a good tool for API testing, it is easy to perform API testing using the intuitive Postman UI. You can also perform API testing automation using Postman. JMeter can additionally provide the performance metrics. If you require to do the API automation then Postman may require good programming skills. Postman supports Javascript programming language for automation. That means you need to write the logic and assertions in JavaScript to automate the API endpoint testing. Manual testers may disappoint and may need help to automate the API endpoints. However, the Testsigma tool can help you to automate APIs without any prior coding knowledge. Testsigma is a go-to alternative for Postman.

Testsigma is a no-code testing tool that can support different types of testing such as functionality testing, API testing, mobile testing, responsive testing, etc.  You can automate API testing just by doing the drag and drop without going in-depth to the implementation level. Interestingly, you can use one tool for all your testing requirements such as functional and API testing. 

Which is better, Postman or JMeter?

Both Postman and JMeter are popular tools and are widely used for testing. They both developed to serve a different purpose. Postman is developed to make API testing fast and easy. JMeter is developed to make performance testing efficient and more reliable. Based on your requirements you can choose either one of them.

Conclusion

Functional testing and non-functional testing are the two most crucial types of testing. Functional testing includes both API testing and UI testing. Postman can help you to perform the API testing, it can also help in debugging APIs during the development. When it comes to nonfunctional testing performance testing is a must-have in web applications. User experience, branding, and reputation rely on the performance of web applications. JMeter is a popular tool for performance testing; it can simulate thousands of real user loads and provide the metrics to your system. However, JMeter can also help in API testing. You can easily convert the Postman test into JMeter tests by doing some configurations. However, these tools are very technical, if someone doesn’t have technical expertise it may be difficult for them to use Postman and JMeter for API test automation. Testsigma can help anyone to automate the API without any requirement of prior coding knowledge.

Frequently Asked Questions

What are the advantages of Postman over JMeter?

Postman provides a user-friendly interface for creating and debugging the API tests. The API response is more readable and does not need explicit pretty formatting, Postman does it by default. Writing automation scripts for APIs is much easier compared to JMeter.