Frontend Testing vs Backend Testing: Differences You Must Know

Frontend and backend testing are two complementary major testing methodologies to validate different facets of an application.

In this article, we will cover the differences between frontend and backend testing, their types, the steps involved, and the best tools for testing. By the end, you will clearly understand the differences between these testing methodologies and why they matter in the development process.

What is Frontend Testing?

Frontend testing focuses on the elements that are to be tested on the display of web, mobile, or desktop applications, particularly the user interface and user experience.

Frontend testing focuses mostly on the following -

• Visual elements: Buttons, links, images, and other UI components.
• Layout and design: Responsiveness across different devices and screen sizes.
• Functionality: Ensuring all features and interactions work correctly.
• Usability: Testing for ease of navigation and intuitive user flows.

Types of frontend testing

1. Unit testing: Testing conducted on single or unit components of your frontend code such as each method call or function.
2. Integration testing: This is used to test the integration or communication between the different elements of the front end.
3. Functional testing: This is intended to check the features and functionality implemented in the frontend application against the requirement document.
4. UI testing: This is a type of testing that focuses solely on the visual appearance of the app to provide validation of the correct display and a good screen look.
5. Usability testing: Ensuring that the end-users find the navigation around the application easy, frictionless, and intuitive.
6. Performance testing: It measures the response time, load capacity, and performance of the application itself.
7. Cross-browser testing: This makes sure that the application runs on most major web browsers and devices.

Example of Frontend Testing with Steps

Scenario: Consider an e-commerce product details page to view the product description, its images, and customer reviews, along with the “Add to Cart” button.

Here are the frontend testing steps:

Step 1: Visual inspection

• Verify that the product image is correctly displayed and in good quality.
• Check that the product name, description, price, and other relevant information are displayed accurately.
• Ensure that the “Add to Cart” button is visible and functional.

Step 2: Layout and responsiveness

• Test the page’s layout on different screen sizes (desktop, tablet, mobile) to ensure it is responsive and easy to read.
• Ensure elements are aligned properly and there are no overlapping or missing elements.

Step 3: Functionality testing

• Click the “Add to Cart” button and verify that it populates in the shopping cart.
• Check that the quantity can be adjusted and that the total price is updated accordingly.
• Test the “Buy Now” button, so that it will navigate the user to the checkout page.

Step 4: Usability testing

• Assess how easy it is for users to find the product they are looking for.
• Check the clarity and conciseness of product information.
• Check if the navigation is intuitive and that users can easily go back or forward.

Step 5: Performance testing

• Measure the page’s loading time to ensure it loads quickly.
• Test the page’s performance under different load conditions (e.g., multiple users accessing the page simultaneously).

Step 6: Cross-browser testing

• Test the page in various web browsers such as Chrome, Firefox, Safari, and Edge, and mobile devices with iOS and Android, to ensure appropriate rendering and course functionality.

Best Frontend Testing Tools

Broadly speaking, frontend testing tools can be categorized into two main types: developer-driven tools and codeless tools.

Developer-driven tools target developers, hence they require knowledge of programming languages and script tests. These tools offer much flexibility and are highly customizable. The other category is the codeless tools, which target non-technical people and allow them to develop tests without coding. More often, codeless tools are user-friendly and easier to learn and use. However, they are less flexible and have limited customization.

Here is a list of the best front-end testing tools that are the market leaders.

Testsigma

Testsigma is a cloud-based, AI-powered all-in-one test automation tool that supports all frontend testing needs with features such as low-code testing, visual regression testing, cross-device and cross-browser testing, testing on devices hosted on clouds, and much more. It features an intuitive user interface with good integration built for enterprise-grade CI/CD infrastructure.

• Test creation in natural language: It allows the creation of test cases through plain English, making it fairly easy for absolutely any team member to come up with tests.
• Self-heal: Testsigma can detect and auto-heal test failures due to UI changes, bringing down the maintenance efforts.
• Record Test Cases: You can use the Testsigma recorder to record the elements on a web page and create test cases on the fly.
• Parallel Test Execution: The test cases can be executed at the same time on several devices and under different types of testing environments, which increases the testing process speed.
• Integrations with popular tools such as Jira, Jenkins, and Slack are natively supported in Testsigma for effortless collaboration and reporting.
• Cross-browser and cross-platform compatibility: Test cases can be executed on 3000+ combinations of devices, browsers, and operating systems.
• Visual Testing: Testsigma allows you to compare screenshots of web pages to determine the visual differences.

You can sign up for a free trial of Testsigma Cloud and start automating your UI testing in minutes.

Selenium

Selenium is a multi-dimensional, open-source testing tool for web-based applications. It supports various programming languages; thus, it can easily fit into various development environments with divergent needs. It supports cross-browser and cross-platform, and it ensures tests run on different browsers and operating systems. In addition, it integrates very well with CI/CD pipelines to have continuous testing and automation. However, one major limitation of Selenium concerns the likely maintenance issues of scripts, as frequent changes are made to the UI of a web app.

Appium

Appium is the ultimate solution for mobile app testing. It supports both native and hybrid application testing, thus, one can have a comprehensive testing solution. Appium also supports cross-platform testing. It means that you create tests once and run them on iOS and Android. Moreover, it integrates well with the CI/CD pipelines, making mobile testing easy. However, its biggest drawback may be the complex setup and configuration of the environment involved in testing, especially for beginners.

What is Backend Testing?

Back-end testing is a testing process for the server-side components of a software application. It ensures that all data processing and logic work as they are supposed to. This type of testing covers databases, APIs, servers, and other back-end processes abstracted from end users but critical in functionality.

It makes sure that data is stored, retrieved, and updated correctly and APIs return expected results upon invocation. The main areas for testing usually include database integrity, server-side logic, data migration processes, and security.

In contrast to frontend testing, which deals with UI and user interactions, backend testing requires a deep understanding of the application architecture, data flow, and business logic. Testers often leverage SQL queries, API testing tools like Postman, and automation frameworks to validate the backend.

Backend Testing Types

Backend testing encompasses various types, each with its focus:

1. Unit testing: Testing each unit or component of the backend code independently.
2. Integration testing: It tests the interaction of various components in the backend.
3. Functional testing: This makes sure that the functionality of the backend meets the requirements specified.
4. Performance testing: Involves back-end response time, load capacity, and overall performance measurement.
5. Security testing: Identification and elimination of all probable security back-end vulnerabilities, such as SQL injection, cross-site scripting, and unauthorized access.
6. Database testing: This ensures that the database is functioning correctly and that data is stored, retrieved, and updated as expected.
7. API testing: It is a way to confirm that APIs return the right set of data and responses.
8. Data validation testing: Testing the entry of data that goes into the back-end to ensure it’s proper and meets the requirements.
9. Concurrency testing: It ensures how the back-end process carries out multiple requests or processes at the same time.
10. Fault tolerance testing: Determines how well the backend can restore a state in cases of failures.
11. Scalability testing: This kind of testing verifies how well the backend can scale with rising workloads and how it can grow automatically.
12. Stress testing: This tests the backend’s performance under extreme conditions to identify its breaking point.

Example of Backend Testing with Steps

Scenario: Consider a new order processing system is being launched for an e-commerce site. The system is expected to handle order placement, payment processing, inventory management, and shipping.

Steps of Backend Testing:

Step 1: API testing

• Test the endpoints of the API available for submitting an order, processing the payment, and then retrieving the status.
• Verify that the API returns the correct responses and data formats.
• Ensure that the API handles error conditions gracefully.

Step 2: Database testing

• Test the queries of the database for saving information about the order, customer data, and inventory details.
• Verify that data is stored, retrieved, and updated correctly.
• Ensure data integrity constraints are enforced.

Step 3: Business logic testing

• Test the system’s calculations for order totals, shipping costs, and taxes.
• Verify that the system correctly handles different payment methods and currencies.
• Ensure that the system updates inventory levels accurately.

Step 4: Performance testing

• Test the system’s performance under different load conditions, including, but not limited to, the peak traffic during sales periods.
• Determine the response times and pinpoint any bottlenecks.
• Ensure the system can handle the expected workload.

Step 5: Security testing

• Check for exposure to vulnerabilities like SQL Injection, Cross-Site Scripting, and Unauthorized Access.
• Ensure that sensitive customer information is kept secure.
• Verify that payment processing is secure.

Step 6: Data Validation Testing

• Test that inputted data (e.g. order quantities, payment information) entered into the system is validated.
• Make sure that invalid data is rejected and proper error messages are human-oriented.

Step 7: Error handling testing

• Test how the system responds to errors such as payment failure and lack of inventory.
• Provide the user with proper error messages.

By following these steps, you can ensure that the e-commerce order processing system is functioning correctly, secure, and can handle the expected workload.

Best Backend Testing Tools

Now that we have understood what Backend testing is, let’s discuss the best tools available in the market for automating backend testing processes.

Testsigma

Testsigma is a cloud-based, AI-powered test automation tool that has a user-friendly interface to create, run, and maintain tests easily. You can easily perform parallel testing of APIs, integration testing, regression testing, and much more on 3000+ devices hosted on the cloud. Testsigma is a low-code, no-code test creation platform that allows you to create tests using a simple natural English language.

Features of Testsigma:

• API testing: Testsigma facilitates the creation and execution of API tests in natural language, hence easily defining test cases by validation of API responses.
• Data-driven testing: You can parameterize test data to test different scenarios and ensure the robustness of an API.
• Integration with popular tools: Testsigma integrates with popular tools such as Postman, Swagger, and OpenAPI for easy API testing. It has inbuilt self-healing capabilities.
• Parallel test execution: Test cases, across multiple environments, can be run concurrently, which speeds up the testing.
• Integrates with CI/CD pipelines: Testsigma integrates with popular CI/CD tools like Jenkins, GitLab, and Azure DevOps for continuous testing.

Postman

Postman is a widely used tool for API development and testing. It provides a very user-friendly interface for creating, sending, and testing API requests. You can easily define request parameters and headers with bodies using Postman and inspect the responses. It also supports features related to environment variables, collections, and automation, which makes it an excellent tool for back-end testing. However, Postman shines in manual testing, on the other end, it lacks a bit in efficiency when large-scale automation scenarios are organized.

JUnit

JUnit is a testing framework for creating unit tests in Java applications, developed to provide a simple and flexible API for creating and running test units. It can run tests for individual methods or even particular classes of the backend codebase. Writing unit tests means that individual unit components are functioning well and it isolates the bugs at a very early development stage. However, JUnit is not perfectly well-suited when the functional relations of components are complex.

Frontend Testing vs Backend Testing — Major Differences

Conclusion

Frontend and backend testing are the two crucial types of testing in the software development process. Frontend testing ensures the best possible user interface and user experience, while backend testing focuses on checking the server-side components for proper functioning and interaction with databases and APIs. Understanding these differences between the two types of testing and using test automation proper tools, will help developers construct robust, reliable, and high-quality software that will benefit both users and stakeholders.